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Bulletin of the Scientific Instrument Society No. 46 September 1995 Bulletin of the Scientific Instrument Society LSSN0956-8271

For Table of Contents, see inside back cover

President Gerard Turner

Honorary Committee Howard Dawes, Chairman Stuart Talbot, Secretary John Didcock, Treasurer Willem Hackmann, Editor Michael Cowham, Ad~wtising Manager Trevor Waterman, Meetings Secretary Gloria Clifton Jane [nsley Arthur Middleton Alan Morton

Membership and Administrative Matters The Executive Officer (Wing Cmdr. Geoffnm] Bennett) 31 High Street Stanford in the Vale Faringdon Tel: 01367 710223 Oxon SN7 8LH Fax: 01367 718963 See inside back cover for information on membership

Editorial Matters Dr. Willem D. Hackmann Museum of the History of Science Old Ashmolean Building Tel: 01865 277282 (office) Broad Street Fax: 01865 277288 Oxford OXI 3AZ Tel: 01865 54058 (home)

Advertising Mr Michael Cowham The Mount "loft Tel: 01223 263532/262684 Cambridge CB3 7RL Fax: 01223 263948

Organization of Meetings Mr Trevor Waterman 75a Jermyn Street Tel: 0171-930 2954 London SWIY 6NP Fax: 0171-321 0212

Typesetting and Printing Lithoflow Lid 26-36 Wharfdale Road Kings Cross Tel: 0171-833 2344 London NI 9RY Fax: 0171-833 8150

Price: £6 per issue, including back numbers where available. (Please enquire 04 Exec. Officer if sets are required.) The Scientific Instrument Society is Registered Charity No. 326733

X-ray image of a metal grid taken in THE EM)iF.'.; G.A,ZETTL Crookes' laboratory, but not by him as he -. + .__ was in South Africa when Rontgen's discovery was announced. There is also the metal grid and the X-ray tube used in producing this image. Among the selec- tion of early X-ray tubes are several ~n~anl..,m,u' u '1 tl u+ I* "+~ • ~., ,~ .,.l.~,,~l..,- 6o. all~ III It X |! r-+-''-- ~,~.ll. Jackson focus tubes, the version used in the Middlesex Hospital in c. 18b%7, the tube and induction coil (a fine specimen by Alfred Apps) used by A.A. Campbell Swinton, and a 'Penetrator' tube from MI 4 early 1900 as marketed by W.Watson & Fig.l Eric Fraser's poster fi~r the Post Sons. The ephemera include two X-ray Office celebrating Hertz~ 1888 disco~¢ry. postcards (1914 and 1918) and a charming Christmas card (1902). The core of the Apart from the wrong date, the artist has ...... k ~ 0. + ,. :I al + • erroneously turned Hertz's laboratory experi- exhibition is based on the IEE's Silvanus ment into a wireless telegraphy set operated P. Thompson collection, augmented by by a Morse key. An etvcatit~ poster which material from elsewhere such as the teaches us to beu~are of artistic (historical) Science Museum and the British Institute n~constructions. of Radiology.

Fig.2 Skeletal lady in The Ladies Gazette Making Waves The University of Siena held a very fine of 7 March 1896. X-ray exhibition in May and in the usual I suggested in March (No. 44), that the Italian manner produced a lavish catalo- theme of the September issue should be report on the AGM). The other papers gue? The most interesting are probably the twin discoveries of wireless and X- were Peter Delehar's 'Wheatstone the early X-ray sets, including a twin- rays, whose centenaries we are celebrat- Abroad?', John Bradley's 'Early Aircraft plate Wimshurst by A. Dall'Eco of Florence which is exhibited with a ing this year. Since no one dissented, this Instruments', my own 'Marconi and the 'Maltese Cross' Crookes' tube and hand- is what I have done.' The scene is set by Transition from Telegraphy to Wireless screen, a fine portable machine with Tony Constable, an historian of early Telegraphy', and Stuart Talbot's 'Astro- Ruhmkorff coil, and an even more wireless and a founding member of the labes and Electrotypes: an Enquiry'. This portable Spanish machine in a suitcase British Vintage Wireless Society. His 'The paper was got ready in time for by SANCHEZ Piedrabuena, 1912. There Birth Pangs of Radio' (Fig. 1) was given publication in this issue. are also a variety of X-ray tubes and at the First Session of the international many other accessories. Another exhibi- conference on 100 Years of Radio, hosted The discovery of X-rays and wireless lion is held in the Montreal Museum of recently by the Institution of Electrical fired the public imagination. The possi- Science and Technology (see 'Current and Engineers in London. ~ Paolo Brenni bilities of the new science-based technol- Future Events'). continues the theme by taking as his ogies seemed to be boundless. subject Eug#ne Ducretet, the foremost Contemporary humorists, cartoonists French maker contemporaneous with (Fig. 2), and poets found them a rich Bologna, the birthplace of Marconi, was Popov and Marconi who pioneered the source of inspiration. 'Lines on an X-ray the venue earlier this year of a beautifully marketing of wireless apparatus. In the Portrait of a Lady' published in Life of designed exhibition (judging by the twenties this firm produced commercial 27 March 1896 has caught the mood catalogue) entitled Radio Fram l~arconi sets that are now prized collectors pieces. splendidly: to the Music of the Unit~erse." ih~ides Ralph Barrett is known for his reenact- unique photegraphs featuring Edouard ment of famous scientific experiments, She is so tall, so slender, and her i~mes Branly, Alexander Popov and Agusto but for the IEE conference he was Those frail phosphates, those carbonates of lime Righi (Marconi's scientific patron), and Marconi. His performance was not only Are well produced by cathode rays of course of Marconi and his family, there credible but also evocative. He demon- sublime, were also exhibited some ve~' interesting strated Marconi's epoch-making experi- By oscillatkms, amperes and by ohms. original pieces of apparatus such as a ment of 1895 (repeated in England on Her dorsal vertebrae are not concealed 'bastardised' 10-inch induction coil used several occasions, including on Salisbury By epidermis, but are well revealed... to allow weak Morse signals coming Plain in 1896). Ralph's models of this from the other side of the Atlantic to be apparatus and that of Popov is the There have also been a number of heard on a telephone receiver, replicas of subject of this issue's 'Facsimile File'. present-day exhibitions, large and small, the Righi tw,cillator (transmitter) and Little of the pioneering wireless appara- several of which have come to my coherer as used by Marconi in his 18•5 tus has survived as most was canniba- attention. The WiJrzburg exhibition was experiments, the famous 'multiple tuner' lised for later experiments. Among the described in the previous Bulletin (p. 3). produced by Marconi Wireless Co. in c+ most perfect surviving specimens are The X-ray exhibition nearest to home 1907, a 'mock-up' (including some those of 1897 in Teyler's Museum which opened in the lEE (London) in August original material) of a Marcimi's ship set will he reproduced in the next issue. and closes on 28 September. ~ This of c. 1902, a fine WWI French-made compact exhibition includes several military transmitter, and a beautiful The celebration of the discovery of X-rays antecedents of the X-ray tube such as an example of the Marconi MR I]4 vah'e is represented by Nell Brown's 'A New intricate early Geissler tube, Crookes' receiver. The story is brought right up to Kind of Rays'. This was one of the five 'Maltese Cross' tube of the 1870s, and a date with the intn~uction of Intemet in papers given at this year's AGM held on (Philip) Leonard tube for the study of the 1970s for military purposes and now 6 July at the Society of Antiquaries in cathode rays which set R6ntgen on the used universally (see Giles Hudson's London (see 'Announcements' for the course of his discovery. There is the first 'Instruments Caught in the Web' below).

Bulletin of the Scientific Instrument Society No. 46 (1995) L Exhibition Talks in Museum of the History of Science

There will be a series of exhibition talks in association with 'The Measurers' Exhibition. These will be held at 6 p.m. in November. The dates are the 6th (Jim Bennett), 7th (Gerard Turner), 8th (A. Meskens), and the 10th (A. Simpson). Details from the Museum.

Antique Telescope Society Fig.3 Set of apparatus for Hertz's u¢~e experiments, including one pair of parah)lic mirrors Hransmitter and receitvr) and a wire frame This American society was founded in polarizer. From Baird and Tatlock Catalogue of 1924, p. 546. 1990 and is dedicated to the study, use and preservation of early astronomical instruments and related material. Their Complex devices such as wireless tele- 5. G. Pancaldi (ed.), D/Marconi alia musica quarterly Journal of the Antique Telescope graphy or X-rays are made up of delle stelle (lh~logna: Gratis Edizioni). The exhibition was held from 9 April - 4 June in Society deals with all aspects of telescope components with different origins which collecting, including technical informa- have been grouped together to create or Bologna and other venues outside Italy are being planned. tion, restoration tips, and historical make use of a new effect. In the history, of papers. They are pursuing the idea of physics new effects were usually created holding a meeting in the UK in 1996 or with existing apparatus. Once the dis- New Director of History of Astronomy Joins Adler Planetarium 1997. Details can be obtained from the covery has been made, the evolution of Secretary, Walter H. Breyer, at 30 Green the original components into increasingly Valley Road, Wallingford, PA 19086, specialised apparatus could begin. Thus, Dr Bruce Stephenson was appointed the USA. Tel: I (215) 556 2227. the crude prototypes turn into well new Director of Adler's renowned developed devices such as the apparatus collection of historical astronomical Auction Team K61n for the Hertzian wave experiments artifacts on 3 July. One of his first tasks marketed by Baird and Tatlock in the is to create a major exhibition concentrat- In their recent press release state that the (Fig. 1920s 3). ing on astronomical instruments and sales of technical antiques are booming in ideas from the 1500s to the 180(O. He is Germany and give some of the auction Marconrs death in 1937 was marked by a also responsible for engaging interna- prices that have been achieved: brass two-minute silence on all the world's tional scholars to work on the Adler microscope by R. Feuss of Berlin (£1,175), radio stations in order, it was said, to collection, developing and managing the original 'Zippo windproof lighter' of return the aether to the silence that collection'saccessibility through Internet, 1940 (£267), and an HMV Model 900 existed before Marconi's experiments and updating the catalogue. He has horizontal mirror TV of 1937 (£2,350). which have changed our lives for ever. written two books on Johannes Kepler. Notes and References Centre for the History of Defence Saturday Opening of Museum of the Electronics History of Science, Oxford I. I also promised that thisLssue would have the review bv Jim Bennett of Gloria Clifton's According to its publicity pack the broad Dzrecto~ ~. Brih~h Scwnt!ficInstrument Makers From the beginning of October the aim of this recently established Centre is 1550-18:30. l ht'~e that this review will now Museum changes its opening. Instead of to contribute to the study and public appear in the next Lssue. Monday to Friday, it will be open to the awareness of the history of electronics. 2. Thisconference which tca)kplace ~)m 5- public from Tuesday to Saturday, in line Initially the Centre will concentrate on 7 September was announced in BulletinNo. with the other museums of the Uni- radar, sonar, communications, and elec- 43. [t was organised by the Science,Education versity of Oxford. Opening hours re- tronic countermeasures, together with and Technology Division of the IEE. SIS main as 12 noon to 4 p.m. The Library their wider social consequences, by members should keep an eye on the activ- will not be available, but readers can means of actual apparatus and state-of- ities of this group as their occasional lectures continue to make appointments to attend the-art computer graphics. The latest at the IEE and Summer Weekend Conferences database technology will store and can be a useful source of information on the on Mondays. The office and other histon,,' of electrical technoh)gy including departments of the Museum will keep retrieve material that includes documen- instruments. The papers l(g) Years of Radio to the regular working week. tary, pictorial and oral archives. Thus, it have been published the IEE's Ctmference will become an important resource for Publication No. 411, given free to the the collector of this type of material. For delegates. Museum of the History of Science Graduate Course further information contact Dr John 3. A New Kind of VJ,~ion. The DIsc.rt~e~ qf X- Beavis, the Director of the Centre, or the Ra~,s (London: lEE Archives Exhibiti(m, 1995). Manager, Brian James, at the Department This is not an exhibition catalogue, but an This twelve-month M.Sc. course based on of Conservation Sciences, Boumemouth espy concerning the origins of ×-rays and of the Museum's collections and expertise University, Poole, Dorset BH12 5BB. Tel: computer aided tomography (CAT or CT will start in October 1996. The main focus 01202 595178/fax 01202 595255. scanner). will be on the rble of instruments in the 4. Paolo Stefani, Francesca Vannozzi and history of science and technology from Look it up in Ganot~ Fausto Cassi (eds), L'avwntura dei Ra)~gi X ancient times to the early twentieth ~1895-1995~. Dal radiah~o uni~'rsale... all'uni- century. It will also cover collecting and On my desk dropped recently a privately ~vr.~ de/Rag¢i X (Florence:Giori and Gambi, the place of museums in the history of printed pamphlet by my good friend V.K. 19~). Copynght: lstitutodi Scienze Eidiolo- science. Further information can be Chew. It is a descriptive list of papers, giche e RadiologJche delrUniversitAdi Siena. obtained from the Keeper. mostly, unpublished, which he wrote

2 Bulletin of the Scientific Instrument Society No. 46 (1995) during 1980-94 when a Research Fellow respect, the history of science and somewhat fluid state of lntemet stan- at the Science Museum, after he retired as instrumentation included. dards means that it has been necessary to the Keeper of Physics. It is full of gems provide two versions of every page: one such as the origins of Fletcher's trolley, The Museum of the History of Science in coded to HTML 2 standards and the the whereabouts of the hydroclimax, the Oxford has recently sought to take other to HTML 3 standards - the latter history of the Eureka can, the origins of advantage of these opportunities by providing for tables, coloured back- the Christie-Wheatstone bridge, and the launching an Intemet service (for want grounds, centred text and other razz- birth, life and death of the radiophone. of a better term) of its own. The matazz. The majority of images are The pamphlet is very rare as only ten Museum's pages (which can be found at supplied as interlaced GIF files, JPEG copies have been printed (and I promise the address files having been rejected despite their to return my copy to the author soon). h t t p ://www.ox.ac. uk/depart men ts/hooke/) smaller size due to the inability of some Having, over the years, read several of number around 350 with over 150 browsers to deal with them. his carefully researched papers (in manu- images. They include general informa- script form), ! am convinced that I will tion about the Museum, details of the never say about his work that 'lit] has In providing information via the World new graduate course, an illustrated list of Wide Web, the Museum of the History of taught me more about penguins than I the Museum's publications and post- wanted to know'. Science in Oxford joins a growing band cards, an electronic incarnation of of museums and other institutions in the Spha,ra (the Museum's newsletter), and field of science studies. The Istituto • Instruments Caught in the Web the beginnings of an Image Library, Museo di Storia della Scienza in Florence which at the moment contains pictures, has its own pages at As few can have failed to notice given the with brief captions, of instruments, "http://galileo.imss.firenze.itf', the Science exhaustive media attention it has portraits, early photographs and other Museum, London at ceived, the last few years have seen the material. In addition, and most notably, it "http:/~narw.nmsi.ac.uk/", and the Mus6e rapid growth of the Intemet - the World is possible to pay a 'virtual visit' through des Arts et M~.~tiers, Paris at Wide Web or 'global electronic super- the Museum's web pages to the current "http://u~b.cnamfr/museuraf', with Rice highway" as it is often called - which special exhibition The Measurers: a Flemish University's Galileo Pro~'t at now links together electronically a Image of Mathematics in the Sixteenth "http://es.rice.edu.80/ES/humsoc/Galileo/f'. frightening proportion of the world's Century. A useful index to other museums and population. Leaving aside such weighty related sources is the Virtual Library's issues as its implications for the creation For those interested in the technicalities, page at of an information Utopia, the Intemet, the Museum's pages are held on 'sable', "http://u,ww.asap.unimelb.edu.au/hstm/ more straightforwardly, offers some one of the University's UNIX mainframe hstm mus.htm". immediate opportunities for those computers; they occupy around 130 whose rble it is to educate and entertain megabytes of storage space, 95% of the public, or sections of it, in whatever which is occupied by the images. The Giles M. Hudson

Colin Ronan Colin gonan was not well-known to some of our members, but those of us who attended the joint meeting of our Society at the Royal Astronomical Society at Burlington House remember his robust assertion - and demonstration - that the reflecting telescope might well have been invented by Leonard Digges long before it was as,~embled by l.~ac Newton or William Herschel (see Bulletin, No. 37, pp. 1-6). Sadly, Colin died earlier this year at 72, and before he could complete many of the pro~, books or papers he had in mind. A Thanksgiving Service for his life took place on 27 July and two members of our Society attended to bid farewell. The venue was the Queen's Chapel of the Savoy. The Crown has held this by right since old John of Gaunt ('... time-honoured Lancaster..', Shakespeare, Richard ll, opening line) acquired the land in 1361. His son, Henry. Bolingbroke, became Henry lV in 1399. The service was marked by marvellous singing by the small male voice choir and three moving and entirely different tributes given by Donald Franke. Patric Moore, and Mark Ronan. It seems that Colin, apart from many different taJents and interests, was possessed of a wicked sense of humour, part of which was shown during his act as a talented amateur conjurer; halfway through the show he would wash his hands in a basin of water, and having dried them would then huh the contents of the basin at his startled audience, who would instinctively duck, only to find they had been showered with ... confetti. A little over an hour later we emerged into the hot sun but feeling glad to have been there. Colin had a wonderful send-off Arthur Middh'ton

Back Cover Illustration This charming cartoon from The Marconigraph of March 1913 by the cartoonist E.G.O. Beuttler, who was a regular contributor to this journal, is of a typical ship's 'wireless cabin' of this period. In fact, he may well have been inspired by a photograph of such a cabin published in The Marconigraph of June 191 l, except that their 'Marconi Officer' is attentively taking down a radio mess,ige. Our cart(x)nist, perhaps more true to life, has caught his operator having a quick nap at 'Five Bells'. The key items of this ~ K.W. ship set that can be identified are the small tuning lamp in the top left-hand corner, the battery charging panel at the right-hand side of the porthole, and on the table the multiple tuner which is connected to the magnetic detector (secured directly above it on the wall). The operator's earphones are connected to the detector. He is resting his feet on the main condenser. On the right of the multiple tuner are two morse keys, and to the right of them can just be seen the 10-inch induction coil of the trarmmitter. Several of these items, such as the magnetic detector and the multiple tuner have become much prized collector's items.

Bull~m of the Scientific Instrument Society No. 46 (1~) Announcements

MINUTES OF THE 11TH ANNUAL GENERAL MEETING

of the Scientific Instrument Society which was held at The Society of Antiquaries, Burlington House, London Wl ~m Thursday 6th July 1995 at 4.15 pm

H.A.L. Dawes, in the Chair 4. Trelsure#. Report The Chairman, concerned with i) Presentation and adoption of the membership confidentiality, sug- No apolol~s of absence were received. Accounts Year End 31st December gested that a flyer could be dis- 1994 tributed to Irish members with the A copy of the accounts was Bulletin who would then be free to 1. "['he minutes of the AGM held on circulated at the meeting and respond individually. Thursday 30th June 1994 were reflected a surplus of £950 for the approved. These were circulated in Bulh'tin No. 42. year. The principal costs were E) Ion Darius Memorial Lecture Bulletin printing and postal Arthur Middleton had attended the charges. The Treasurer paid tribute first Memorial Lecture and had 2. Chairman's Report to the efforts of the previous holder, The Chairman said that the year hoped to see more Scientific Instru- Brian Brass. Computerisation of ment Society members there. The had been both exciting and pro- records had greatly facilitated the gressive for the Society. A generous lecture had been inadequately pub- task and complete membership licised to members as the organisers donation of £15,000 from the confidentiality was assured. The Renais~nce Trust was gratefully had failed to contact the Editor or question of student subscriptions arrange a timely flyer for inclusion acknowledged. The Committee was raised by Dr. Charles Mollan - had decided to dispose of the with the Bulletin (it was announced this category had existed in pre- interest from this fund by support- in No. 44). It was hoped to rectify vious years but in view of the this in the future. ing r~arch into the history of printing and postage costs was not scientific instruments and the first c~msidered viable by the Treasurer. recipient of this Award was Dr. iii) Dr Gloria Clifton thanked the Stephen Johnston wht~se paper on ii) Re-election of Auditor Society for the support in the Anthmometers would be extracted Mr. S. Emin was re-elected Auditor publication of the Directory of for a future i~ue of the Bulh'tin.The to the Society being proptr~L-,d by T. British Scientific Instrument Makers Society had assisted the publication Waterman and seconded by A. 1550-1851 which had been pub- of The Dtrt'chn'y of British Scientific Middleton. lished to great acclaim in May 1995. Instrument Makers 1550-1851 by underwriting 150 copies which hacl Election of Members to the iv) The Chairman thanked Commit- been made available to members at tee members who were retiring at a preferential rate. Committee 1995/96 In accordance with the Constitution the AGM and made particular all Officers and Ordinary members reference to Peter Delehar, a foun- The Societ~"s Annual Lecture was of the Committee resign at the der member of the Society, for his given by Prof. David King in Annual General Meeting. contributions to the Committee over November 19q4, this was excellent so many years. He also then and well received. We look forward The kfllowing Officers were pro- thanked the five speakers for their to Prof. John Heilbron's Lecture in posed and elected for 1995/96: interesting variety of Lectures. December 1995. Officers 1995/96 In summing up, the Chairman said The Society's visit to Florence in Chairman - Howard Dawes the Society is nothing unless it March 199g was a great success and Treasurer - John Didcock maintains its high standard of the Meetings Secretary was to be Editor- Willem Hackmann academic influence in the Bulletins congratulated on the meticulous Hon. Secretary - Stuart Talbot and Lectures. We are very keen to organimtion. Meetings Secretary - nurture our close links with the Trevor Waterman Science Museum, the Museum of 3. Secretary's Report the History of Science in Oxford, the The Secreta~' inh~rmed the meeting Ordinary members 1995/96 National Maritime Museum and the that the current paid up member- Gloria Clifton Whipple Museum at Cambridge. ship numbered 560. This was a 1~, Mike Cowham Our Committee includes represen- incream over this time last year. Jane lnsley tatives from each of these great I'romotional avenues were always Arthur Middleton collections, with the exception of being sought. Over,as representa- Alan Morton the Whipple and a meeting is tives had received publicity materi- arranged there to forge closer al for distribution. The Society's 6. Any Other Businetm links. In short, the Society is in Executive Officer, W/Cdr Geoff~y i) Irish Memberships go~ heart and we look forward Bennett was congratulated on his Dr. Charles Mollan enquired to another interesting year. administration of the Society's whether it would be possible to affairs. have a list of members in Ireland. The Meeting closed at 4.45 pro.

Bulletin of the Scientific instrument Society No. 46 0995)

i SCIENTIFIC INSTRUMENT SOCIETY INCOME AND EXPENDITURE ACCOUNT FOR THE YEAR ENDED 31st DECEMBER 1994

1993 1994 RECEIPTS 15,073 Subscnptions and joining fees 17,651 566 Donations 59 572 Income from events (918) 1,161 Interest received 1,387 (3,035) Monograph sales 293 143 Profit on sale of ties and binders 169 £14,480 Total receipts for the year £18,641

EXPENDITURE 11,928 Bulletins - (Nos. 40-43) - cost 12,605 (3,821) Advertising receipts 4,304 (1,116) Sales 1,012 5,316 6,991 Net cost of bulletins 7,289 1,680 Secretarial costs 2,200 848 Cost of meetings 742 -- Insignia 307 5,261 Printing, postage and stationery 5,933 716 Sundry expenses 76~ 250 Accountant's remuneration 450 £15,746 Total expenditure for the year £17"690 14,480 RECEIPTS (see above) 18,641 15,746 EXPENDITURE (see above) 17,690 (1,266) EXCESS OF RECEIPTS OVER EXPENDITURE IN THE YEAR (1993 = deficit) 951 20,970 Add: Surplus brought forward 19,704 Special Fund - Donation from Renaissance Trust 15,000 £19,704 Accumulated Fund at 31st December 1994 £35,655 Represented by: Bank balances - Lloyds Bank 27,968 - National Westminster 15,000 22,970 42,96~ 175 Stock of ties and binders 175 322 Debtors and accrued income ~1 23,467 43,4M 3,763 Creditors 7,77q £19,704 Net assets at 31st December 1994 E.35,bg~

J. Didcock ~ H.A.L Dawes FCA Treasurer Chairman

ACCOUNTANTS REPORT TO THE MEMBERS OF SCIENTIFIC INSTRUMENT SOCIETY

1 have prepared the attached income and expenditure account for the year ended 31st December 1~4 fn,m the b~ks, records information and explanations furnished by the ~ciety and certi~, it to be correct in accordance therewith.

S.P Emin FCA, Chartered Accountant 19 Gh,ucester Hour, Courtland~ Sheen Road, Richmond. Surn'lt TWill 5BB 28ih April 1995

Bulletin of the Scientific Instrument Society No. 46 (1995) The Birth Pains of Radio

A.R. Constable

I Fig.3 Hertz's simple transmitting oscillator u~ich u~as connected to the h(c,h-z~oltac,e terminals of an reduction coil. See A. Constable, "The Hertz Experiments - A Centenary', Bulletin of the Scientific Instrument Society, No. 17 (1988), p. 11.

ago to reduce the above definition to the phrase Hertzian u,az~ wireless telegraphy and abbreviate it to HWT. Thus radio was born when HWT came into existence unequivocally.

When it arrived, the new technology of HWT brought together the well devel- Fig.l English telegraph office of the mid-nineteenth century.. From oped nearly sixty year old technology of D. Lardner, The Electric Telegraph Popularised (London: Walton electrical telegraphy and the incredible and Maberly, I855L p. 113. scientific achievement of Heinrich Hertz.

By the time Hertz was confidently It is quite clear that radio, however it is demonstrating the transmission and defined, has been with us for about a reception of electromagnetic radiation century. But, like many grand old over distances of twenty or thirty centenarians, there is perhaps a little wavelengths in 1888, electrical telegra- doubt about the timing of the moment phy was a fully developed technology of its birth. Such doubts may not be very with wires stretching across the con- surprising. New technologies often do tinents and oceans of the world (Fig.l). not have precise birth dates; they evolve into existence out of the interplay From the mid-nineteenth century, there between need and the devices created to was a fringe interest in telegraphy with- fill the need. Delayed births can occur out wires. Such men as Morse 0842), due to the slow appreciation of how new Lindsay (1853) and Preece (1882) used the scientific principles or discoveries may conductive properties of the earth and the contribute to existing needs. waters of rivers and estuaries. ~ Thus wireless telegraphy emerged as a proto- technology which occasionally filled a In the case of radio, difficultiesmay arise real need and thereby qualified as a true if we do not define the word carefully. technological development. Primitive The word radio, usually as an epithet, pre-Hertzian wireless telegraphy arose may simply mean that part of the electro- out of the highly specialised local need magnetic spectrum spectacularly re- to continue an existing telegraphic service vealed by Heinrich Hertz in 1888. It after a cable failure has occurred. This may also mean apparatus which can be small but important need found a used for what is nowadays called radio primitive solution from which the notion communication. of wireless telegraphy grew steadily. Its very existence prompted much specula- By radio we here mean the transmission and tion, the further recognition of need and Fig.2 I-tert:'~ orz~inal cot~fic,uration u4zici reception ,~ intell(g,ence using a u¢ll defined the frustration that came from the ,~l~,ed into his instruments with parabolic portion of the electromagnetic spectrum inadequacy of the technology, retl,'ctors. without the u~ of connecting wires between transmitter and recek~er, in the earliest The use of electromagnetic induction to forms of radio, Morse telegraphy alone achieve practical wireless telegraphy was was used to convey the intelligence and introduced by Preece from about lggS, 2, the defined portion of the electromagnetic and heralded an important move away spectrum was frequently referred to as from the earlier purely conductive Hertzian u~cs. Hence it is completely in methods. Inductive methods were relent- keeping with the technology of 100 years lessly pursued to the end of the century,

Bulletin of the Scientific Instrument Society No. 46 (1995) • .-.

- !

Fig.4 Close-up of Hertz's parat~,hc rt~et- tors with dipole transmitter (left) and receiver (right), with the radio waves drawn Fig.5 Hertz's diagrams in the Annalen der in. Physik und Chemie, 36 (1888) of his parabolic reflectors. Note that m his original apparatus (as illustrated here) the transmitter well after the application of Hertzian and receiver were placed in the better position waves to wireless telegraphy. However, the technique had severe limitations that behind the supporting strut in the focal plane of the reflectors, but he moved them to the would make it useless where the need Fig.6 A rectangular Hertzian detector with was greatest,for communication between front so that they could be better observed in ships at sea. lecture demonstrations. micrometer spark gap and viewing lens. He experimented with a varu'tv of /oops (as illustrated m Fig 3 of Bulletin, No. 17 Around the coasts 04 England, numerous (1988), p.l|. shipping disasters occurred and many 04 comparator method in his experiment them could have been rendered less entitled, 'On the Finite Velocity of severe had wireless communication Propagation of Electromagnetic Ac- been possible, often across quite short tions'.'This experiment could only have the adjustments and polish of his sparking distances. A lighthouse keeper might been understood by those already spheres to produce just the right crackle watch a floundering ship and be quite steeped in Hertz's previous work and that he learned to associate with good helpless without any means 04 summon- Maxwell's ideas. By itself, it would not radiation. Successful reception could only ing assistance from the mainland. Elec- have created the stir we normally be achieved with extreme perseverance. tr/cal cables were often unsustainable in associate with the work of Hertz for the Hertz measured the strength of the waves were still confined to the surfaces turbulent received signals by observing tiny sparks the seas between the mainland of conductors. However, a few days and the rocks where lighthouses were with a simple microscope and noting their afterwards, Hertz published his seminal brightness and length. With a key in the perched. The need for wireless commu- paper 'On Electromagnetic Waves in Air was fully recognised and fiad primary circuit of a spark coil, he operated nication and their Reflection', in which he a system which clearly dem(mstrated the burgeoned into one of considerable pro~ct~ his waves freely across space. ~ transmission and reception of electromag- urgency probably in proportion to the Throughout 1888 he developed his most netic wave pulses. Hertz had ~T~,.ned up advances made in wired telegraphy. All advanced system of apparatus (Figs.2-5) the whole subject of physics to the that had happened so far was to identify with which he showed that elecm~mag- thoughts of Maxwell and exposed what a real problem without any real practical netic waves obeyed the optical laws of solution from the prot~technoiogies of we now call the radio portion of the reflection, refraction and polarisation and electromagnetic spectrum. He had pro- conductive or inductive wireless telegra- he published his results early in 1889 vided a totally new set 04 measuring .phy. When Hertz completed his impress- under the title, 'On Electric Radiation'.' equipment which, without an alteration, ive work in Germany in 1888, the germ 04 Hertz's quite extraordinary experimental was also capable of demonstrating a new a solution was at hand. achievement constitutes what I believe to system 04 wireless telegraphy. Although be the most vivid 04 all experimental Hertz never so used his equipment, it was Hertz's contribution to fundamental vindications of a theoretical I~y of undoubtedly the germ of the future physics was quite astounding. All the knowledge in the entire history of technology, of HWT and the more distant hard thinking of James Clerk Maxwell physics. At a stroke, all other competing technology of global radio communica- and the deep theoretical work of Hertz theories of electricity must either be tion. himself was vindicated the moment Hertz abandoned or modified and absorbed was able to announce his observations of within the firm body of knowledge Do these clear publications of 1888 the dielectric polarizations in insulating prepared by Maxwell. qualify as announcements of the birth of media referred to by Maxwell. He did this radio? Here was the required Portion of with a most ingenious experiment in Hertzian waves were a reality. They were the spectrum thoroughly investigated 1887, 'On Electromagnetic Effects Pro- easily produced with a spark discharge at and theoretically understood and to duced by Electrical Disturbances in the centre of a half-wave dipole. They which, today, we attach the name radio. Insulators'. ~ His results gave credence to were easily detected by a micrometer With Hertz's waves came a completely Maxwell's controversial displacement spark gap in a resonant loop (Fig.6). novel set of equipment to which ail current. However, Maxwell's complete However, those who have tried repeating future systems of wireless telegraphy vindication occurred only when Hertz Hertz's experiments will know only too would be able to trace their origins. further demonstrated that electromag- well the enormous difficulties Hertz Although the scene was fully prepared, netic disturbances were propagated experienced throughout his work with no telegraphic communication was de- through space at a speed close to that of spark generators and resonant loop monstrated and we must be content with light. Hertz accomplished this task early receivers. Successful transmission could marking the occasion as the birth of only in 1888 using a brilliantly designed vector only be achieved by frequently renewing the pre-histo~,or radio.

Bulletin of the Scientific lrmcumen¢ Socie~ No, 46 (1~3) gt~ technology. Of course, understanding will produce better technologies, ones that may be better able to adapt to change.

The work of Hughes might suggest we should pu,~ back the date of the origin of

m.. m the pre-history of the new technology jl from 1888 to 1879. Perhaps so. How- Fig.7 The remains of David Hughes" "conduction through the air' ever, Hughes' work was essentially apparatus. forgotten and only recalled after the arrival of HWT. Such work often occurs in the history of newly forming technol- Technologies often have a recognised pre- for the learned men to (correctly) ogies, work that lies dormant and fails to history when it is possible to say, usually pronounce Hughes wrong. influence further developments. Hughes' in retrospect, that the move towards a work was, in principle, inspirational. But, new technology began here and pro- But Hughes was right. This u~as the new in practice, there was nobody present gressed, or waited without further phenomenon and, in the terminology of with a sufficiently open mind to receive progression, over a well defined peri(gi the time, air conducti(m (which became that inspiration. Between the work of before the full realisation of its potential. 'aerial electric waves' in his 1899 recollec- Hughes and the technology of radio The pre-histo~, commences when the tilms) was not an unreasonable descrip- communication, there was no continuity tools and the principles are established. tion. The Royal Society experts were - or almost none. Hertz's work marL~ the origin of a pre- wrong - it was not attributable to the h~sto~, which is demonstratablv contin- known laws of electromagnetic induc- New technologies can often be for~ uous with the later phases of the tion. Here was evidence of Maxwell's and we know only too well how such development of radio communication. displacement current loud and clear and gifted writers as Jules Verne, Aldous it was certainly not inappropriate for Huxley or Arthur C. Clarke can paint Hertz's equipment in all its scientific Hughes to refer to it as air conduction vivid pictures of future technologies. sophistication and technological crudity whatever that phrase might have con- When the imagined technologies arrive, was fully capable of being used to convert lured up in the minds of his contempor- we look back with astonishment at the his simple measurable signals of long and aries. Hughes was a man of invention prescience of these writers and wonder short duration into intelligent informa- and imagination. His Royal Society why the orthodox scientificor engineer- tion from 1888 onwards. But a similar visitors were unimaginative and not ing community did not take more notice situation had occurred nine years earlier. well acquainted with the ideas of or did not have similar ideas in the first Maxwell - whose scientific papers had place. The stock of facts which give rise in 1879 David Hughes had performed a been in circulation since 1864. There were to these foretellings are best known to the truly remarkable demonstration of trans- three visits from Royal Society 'experts' scientific and engineering communities mitting and detecting a (Fig.7) series of all equally disappointing. The upshot of but they are also common property for recognised pub, es of electromagnetic all this was for Hughes then to drop any anyone wishing freely to adapt them to radiation over distance of some 450 further experiments on the undi~overed imaginative scenarios. But the scientific metres along Great Portland Street in Hertzian waves, to tidy up the 'dirty community itself indulged in the fore- I.xmdon. ~ He was not at all sure of the joint' that had brought about his telling of HWT. scientific nature of his observation but he investigation of the phenomenon and to recognized it as a new phenomenon. He push it all to one side until prompted to The best known predictions of HWT are called in a most impressive list of recall it nearly twenty years later. those of ThrelfalP, Trotter*, Crookes'" colleagues from the Royal Society to However, this demonstration was fully (1892) and Tesla" (1893). The most witness the event and he sought their witnessed and can go down in history as imaginative and accurate was that of help in explaining it. To the eternal a most significant event. There it was, a William Crookes, one of the scientists shame of the Royal Societ,,; it was all complete and surprisingly advanced who had witnessed the demonstrations of explained away as probabl i, due to the system needing no additions for it to be David Hughes, He was well informed in well known effects of Faradav's laws of put into use immediately as a crude scientific matters and had recently been electromagnetic induction. Of" course we system of wireless telegraphy. But it President of the Institution of Electrical now know that Hughes was using the as was premature and a possible birth Engineers. He was familiar with the work yet undiscovered Hertzian waves, the became, perhaps, a stillbirth. of Maxwell and Hertz though not radi,~, portion of the electromagnetic thoroughly conversant with either. In spectrum, and we are acutely aware that The essential difference between the 1982 he saw with remarkable clarity that he was using a microphonic detector demonstrations of Hertz and those of a communication system might be device which may have functioned like Hughes was one of understanding. Hertz achieved using Hertzian waves and a self-restoring coherer or, a possibly, in understo(xt every nuance of his work in recalled at this ]ate stage having wit- manner ch~ely resembling the rectifying both theoretical and practical terms nessed something of the sort in 1879 in action of c~'stal detectors which came whereas both Hughes and his visitors Hughes' house in Great Portland Street. into u.,~" in 1~)6. We al~ believe that he were in total ignorance. But this was Crookes' essay on this subject shows how u~,d, but abandoned, a filings tube technology which may proceed without a well the knowledge of Hertz's experi- detector not unlike Lodge's of 1894 and full understanding of the scientific ments has seeped into the minds of well that he u.~,d a mercury and iron detector processes at work. Pragmatism is an informed scientists. He referred not only not unlike the so-called Italian Navv adequate motivation for the advance- to the mere passage of information on detector of |899. Hughes himself ment of technology and is often not out Hertzian waves but also to the possibility thought he had hit on a new form of of place in the advancement of pure of syntony, or resonant tuning, allowing 'conduction through the air' and much science. If it works and is capable of signals form different sources to be has been made of this as a valid rea.~m carrying out the task asked of it then it is selectively received. This knowledge

Bulletin of the Scientific Instrument ~¢iety No. 46 (1995) 7

Fig.9 A copy of Ll~ge's "borin)cs tube' coherer, so named becau~ he u.ced rather large iron or steel ix~rings.

/ 1894, RighP 2, or a few millimetres in 1895, B(w,e~, would be achieved. The opposite trend would have been more conducive to telegraphic applications. Secondly, Hertz's work was unique for its completeness and so did not offer quite the same incentive for research as did other trends in modern physics. Whatever fundamental questions might have been asked by scientificinvestiga- tors, they had already been answered by Hertz. As Heaviside" was to remark in a letter to Hertz in 1889, 'There is a lull in the electromagnetic 'boom' . . . perhaps you did your work so well that littlewas left for others'. Thirdly, despite his early training in engineering and his great practical ability, Hertz himself showed Fig.8 Apparatus used in Lodge's Hertz memorial lecture of 1894. no interest at all in applications of his Top left facing Lodge in his mid-4Os: his 'spherical radiator' mounted electromagnetic experiments to telegra- in a copper "hat" which, in turn, is fixed inside a metal-lined laaxlen phy despite hints of such possibilities.He box (as seen on stool below). This box has a variable-aperture rapidly moved in to the field of diaphragm. The receiver consists of a filings coherer (also in a copper theoretical mechanics and left all his "hat') with connecting wires to a galvanometer. Also shown are a great experiments to others. Finally, the paraffin prism and a polarizing grid. See A. Constable, 'Oliver Lodge practitioners of the proto-technoiogy of and the Hertz Memorial Lecture of 1894', Bulletin of the British pre-Hertzian wireless telegraphy had Vmtags Wireless Society, 19 (1994), p. 21. separated themselves from those strongly Maxweilian interests within the scientific community which could have was gleaned from the work of Hertz on later developments. Thus Hughes' led them towards achieving their goal where resonance played an important work, although dormant for so long, through the work of Hem. The so-called part in maximising signal strength and joined the true pred~istory of the new practicalmen were under the leadership of from that of Oliver Lodge who made such technology in 1892. William Preece, a man who was no good use of resonant circuits. Maxwellian. His actions and attitudes From 1888 onwards, the two main were often unpleasant and appear to ingredients of the new technology lay have been guided by ignorance, preju- Crookes' essay was composed with a dice and personal animoai .ty. His words clarity and a prescience that would earn side by side but did not interact. On the one hand, there was the work of Hertz in and his leadership were positively anti- for it a lasting place in history. Although Maxwellian. he did not mention the name of David all its dazzling scientific completeness. Hughes, he referred indirectly to the On the other there existed a well demonstrations he had witnessed. developed interest in wireless telegra- The tragic death of Heinrich Hertz on Ist Crookes thereby provided a thread of phy both conductive and inductive. This January 1894 at the young age of 36 continuity between Hughes and later proto-technoiogy had emerged with prompted a renewed interestin his work. technological developments. Thus it impeccable credentials as a real attempt Scientists and engineers all over the may be necessary to slightly revise to filla true social need, a need that was world could reproduce Hertz's results earlier estimates of Hughes' work. By becoming increasingly urgent. Hertz's with the greatestof ease and Hertz's later this faint thread it really did become waves remained isolated from this experiments were so simple to under- attached to the mainstream develop- technological movement for a number stand by the most practical men that the ments in the predtistory of HWT. It is no of reasons. next stage of progress surely lay within longer correct to state that it belongs to their grasp. The new technology was an abandoned backwater. It had affected Firstly, the nature of Hertz's experiments poised to make its appearance. The birth the thinking of Crookes sufficiently to and their obvious link with Maxwell's was overdue. allow him to make explicit mention of the work emphatically suggested optical effects he had observed 'some years analogies to the scientific community. As already remarked, Hertz's method of earlier' and this mention was sufficient This meant that the overall equipment detection was by no means easy to use. to bring Hughes' work into the picture in dimensions would diminish considerably But, over the six years since 1888 other good time for it to have an indirecteffect and wavelengths of a few centimetres in detection means had been devised.

Bulletin of the Scientific [nsmanent Society No. 46 0995) ,~.:,,--- ~-S'r_~'~~_~~ ~ ._~. ....-- .._...... Fig.ll Mm'h /,~,l'h~l:.cd /,Iwt,Nral,/t ot Alarcom taken shortl.v after he ,lrri~,ed itl Lond,,n in F,'brt,,l~ 1980. The apparatus on his right is a Ri~hi-tyt,e transmith'r, and ,m his h~ft the 'mysterious black box" which contained batteries, a coh,'r,'r a'Id tapl~'r, and relay.

is like that. l_~,vices are often left waiting It is quite p~sible that Lodge saw no in the wings for the moment of inspira- further need to enlarge upon what had tion which brings them onto centre stage. already appeared in flmr consecutive Fig.10 t .at't.;;,: ,,,it,, .Lt,:;,,;; .',trl Hcnrtt With all these devices ~i.,~,d for use the issues of The Eh,ctrician between 8 June Jackson. the R,ntal X'azw's plon,'er t!f wireh~,s new technology could hardly fail to and 6 July 1894.'" That said it all. After tch'gr,lt,h ~ it1 1897. receive a significant En~st at any time. the Oxford demonstrations Lodge went The time came on 1st June 18'~4 when on holiday and did not pursue what was Oliver Lodge delivered a k'cture at the potentially another major turning point Fttt(.k.rald had learned how to detect Royal Institution (Figs. 8-9) on the 'Work in the development of science and Hertzian waves with a DC galvanometer of Hertz' where he introduced his technology. His Oxford lectures lan- connected a.~vmmetricallv to a Hertzian coherer, a detector based on Branlv's guished but it was later recalled that his It~,p receiver. Lodge and lhrelfall had tube. The lecture was published in 1"he signals may have developed into recog- used Gei.,,sler's tubes as visual detectors. Eh'ctrician '~, and it al.,~) appeared as a nized Morse letters, though the recollec- Sara~in and Fh, la Rive had perfecttxl the ~=parately published b,n~klet. This was tions are .~mewhat ambivalent. orig,nal Hertz apparatus to .~uch a degree undoubtedly the significant boost nettled that ttertzian It~p receivers, though still to push a meandering pre-histo~ into the This did not really matter as far as the .~mewhat restricting, could now be fulh,' fledged technology of HWT. Was continuity of the technolo~/ was con- rcliabl.v employed as ~igna] detectors. this June lecture perhaps the moment cerned. His June lecture at the Royal when radio was born? Institution was the real turning point As well as these imprmement~ the about which everything else would hterature was full of interesting efforts Lodge had now assembled the most hinge. The historical continuity is trace- which scienti.~ts or engineers could, with ~,nsitive set of equipment ~) far encoun- able through this lecture alone.'Whatever ,~me etfort, have harnes.~,d to the .,,ame tered for bringing about the full and he did at Oxford played no part in purpo,~,, ttad the scientific world appre- practical application of Hertzian waves stimulating the emergence of the new ciated the importance of rectification in to wireless telegraphy. But in principle he technology. Lodge abandoned any ad- the detection pr~'t.~.~ much was avail- had, at this time, done little more than his vances he may have then introducecl. He able. The precur.,~r of the .,~did ~tate predece~,.,,ors, Hught~ and Hertz. His must have attached little or no iml~r- dio.te ~a~ reported by Braun" in 1~74 system was better and his understand- tance at the time to what additional but tt only came into u.,~" a~, a detector ing was without parallel. But in June effects he had demonstrated, but he was rectifier in I~I~. ,X~ early a~ 18/0, Edi~,n'" l~q4 he did not use his system for to attach a great deal of iml:mrtance to had ob-.erved and patented a thermionic wireless telegraph.,,' and nor did the them later. device that would not be recognized as a publi,,hed versions of his lecture state that it could be .,~, used. detector until Fleming almost acciden- The publication of his June Lecture, tally ,tumbled acro,~, it in 19114. Thermal however, was about to stir the imagina- dettx-tor,, were u.,~'d in 188'4 by Gregory"" tie rel~,ated his Io:ture later the same tions of three important characters, but they did not play a ~ignificant r61e ,,ear and by August some ~tandard Alexander l'opov, Henry Jackson until u*,d by Fe~,,enden in 19112. In 18th~ telegraphic instruments may have been (Fig.10) and Guglielmo Marconi. What- Branlv" hail di~cmered the effect of incorporated into his demonstrations in ever effect William Crookes had on the eltxtrical dl~harge,, on the rt'~,istance of ()xford at the instigation of Alexander world of science and invention, that of metallic powder,,, an effect which, in Muirhead. His audiences included the Lodge would outshine it completely. ~ariou,, guises, had appeared many general public physical ~ientists and Taken in combination the two publica- t~mc,, before, t:douard Branlv publi~he~[| physiologists but he made no attempt to tions could have been sensational. hl~ re~,ult,, dr, a ~.rit,, of measurements publish anything he did. Nor did the Significantly, Ix,th i'opov and Jaclc,~m unrt.lated to Hertzian wave dett~tion but engim~.,ring or scientific literature report were naval men fully aware of the need ,n a manner which allowed his filings anything at the time that would lead us to ~nd intelligent mes~ges in maritime tube to be taken up as reliabh, detector to believe that I~,clge had .said or done situations where connecting wires simply relay at any time from lSt~l. Technology anything relating to wireh.~s telegraphy. could not be used. Both men took their

l0 Bulletin of the .'Scientific instrument Society No, 46 (19'#5) guidance from Lodge's June lecture. proposals. He then went to England in 5. IBM.,pp. 124-136. Popov devised a totally automatic February 1896 (Fig.ll) and applied h~r a 6. Ibid.,pp. 172-18~. recording detector by about July 1895 patent on 5 March 1896 0oumal No: details of which were published in 5028) which survives in title only, 7. Fahie {note I), Appendix D, pp. 305-316 January 1896~, but there is no contem- Garratt." He then acquired a letter of 8. R. Threlfall,'The Present Stateof Electrical porary account of the use of this very introduction to William Preece ~m A.A. Knowledge', Presidentailaddress to Section A. sophisticated instrument for wireless Campbell Swinto# ~, dated 30 March Reports of the Australasian As.~xiation (18q0), telegraphy. It was later claimed (in 1896 which contains three important pp. 27-54. 1925) that Popov had transmitted, in elements. Firstly, Marconi is stated to 9. A.P. Trotter, Editorial, The Electrruan, 26 Morse, the words 'Heinrich Hertz' on 7 have, 'come to this country with the idea (1891), pp. 68.%r~86. May 1895 (later revised to: 'eady' 1986 or of taking up a new system of telegraphy 12 l~4arch 1896 or 24 March 1896). Despite without wires'. I0. W. Crookes, 'Some Possibilitiesof Elec- the revisions, in 1945 the birth date of tricity',Fortnightlv Rev/ew, $1 (February 1892), pp. 173-181. radio was declared to be 7 May 1895. Secondly, there is the statement that it This Soviet attempt to re-write Russian 'appears to be based upon the use of II. N. Tesla, 'On Light and Other High history for political reasons makes it Hertzian waves'. Thirdly it is stated that Frequency Phenomena', 1. Franklin Institute, difficult to attach much credence to the 136 (1803), pp. 1-19, 81-98, 161-177, 2~-279, his system appears to be based on the use 351-360, 401-412. uncertain 'memories' upon which it of 'Oliver Lodge's coherer'. This letter relied. It is not difficult to accept that briefly but reliably summarises what had 12. A. Right, 'Electric Oscillations o~ Short Popov made the first completely success- already been achieved, it is a valid Wavelength Pmducin 8 ~ Anaklgous to the Principal Phenomena of Optics', R. ful relay actuated coherer detector with acknowledgement of Marconi's indebt- tull telegraphic capabilities, from his Accad. d. Scienze dell'lstituto di /~/ogna, 4 (18q4), edness to Oliver Lodge and, like all good Pp. 487-59(1. writings we know that he understood birth certificates,it is signed and dated by its potential as a signalling device. We a reliable witness. 13. J.C. Bose, 'On Polarisation of Electric also know that he misjudged the power Rays' (1895), in Collected Papers of Sir ]agadis Chundrr Bose (London: Longmans, 1927), needed for a man-made transmitter, Marconi probably withdrew his original Pp. I-I0. perhaps because he had done so much patent ~, but replaced it with a new one work detecting the presence of distant which was accepted on 2 June 1896, (No: 14. O. Heaviside to Hertz, Letter dated 4 thunderstorms where the power of the 12,039/1896). By this time he and his December 1889, Deutsches Museum MS292fl, transmitting source was considerable. friends know of what quoted in J.G. O'Hara and W. Pritcha, Hert: the importance and the Maxuwlhans (London: Peregrinus/ they did. It is not certain when Marconi Science Mu.~eum, 1987), p. 79 Jackson began his work with simple first contacted William Preece at the GPO apparatus on the deck of HMS Defiance but official biographies state that it was 15. K.E Braun, 'Ueber die Stromk~tung dutch in December 1895. He appears to have in June or July. However, it is not Schwefelmetalle' (On the Electrical Conductiv- begun using a Lodge coherer system in improbable that the first meeting took ity of Sulphides), Poggendorf~ Annalen, 153 (1874), pp. 5~r~,-563. about August 1896 for Morse signalling/: place soon after 30 March 1896, the date Although Jackson's work was quite of Campbell Swinton's letter. It is there- 16. 1". Edism, 'Electrical Indicators', USA independent, the technology was al- fore distinctly possible that some devel- Patent no. 307031, 21 October 1884. ready in existence by this time. In any opment work on Marconi's system took 17. W.G. Gregory, 'On a New ElectricRadia- case, Admiralty secrecy would ensure place in the GPO workshops well befo~ tion Meier', Proc. Ph.us.Sac., I0 (188q), pp. 2o0- that Jackson's work could not slot into the patent date and well before official 2q3. the mainstream of technological devel- trials began. in 18. E. Branly, 'Vanatiems of Electrical Con- opments HWT. ductivity Under Electrical Influence', The" Numerous accounts have been written of Electrrlan, 27 (18ql), pp. 221-222, 448-440. The early work of Marconi was al~ what Marconi did in Italy in 1895 and we shrouded in the secrecy of an intimate 19. O. I~dge, 'The Work t~ Hertz and Some have little reas~m to doubt their authen- t~ His Succes,~rs', The" Eh'ctnctan, 32 {I~4L family affair. We have no fully authenti- ticity. The smooth historical progression pp. 153-155, 18~-190, 204-205. cated accounts or reliable witnesses to his from Hertz through Lodge led to the early work in Italy in 1895. However, we birth of a successful system of HWT by 20. AS. i'l~w, "Pribor I.)[ia Obnaruzenia e Registrirovania Elektricheskih Kolebanev' can be fairly confident from the numer- Marconi and it would seem reasonable to ous writings of Marconi and his family (An Instrument fin" Detecting and Rt~ister- accept that the unwitnessed birth oc- mg Electrical Oscillations), ]h. Russ. Fiz.- that it was his intention from maybe as curred in the late summer of 1895. ghtm. (~shch~oa IPh~sas. Pt. IL 28 (IS~). early as the end of 1894 to use Hertz's However, if we wish the birth of radio pp. 1-14. waves for wireless telegraphy and that he to be authenticated with a witnessed succeeded in doing so during 1895. But birth certificate then Campbell Swin- 21. R.F Ptwock and GRM. Garratt. The this is not enough. Historical certainty l)ri.~tns e~ Mamttme Radr, (l,ondtm: IIM~, ion's letter should be strongly consid- 1972). comes from knowing when the first erecl with its unequivocal date, ,30 March authenticated witnessed account of Mar- 1896. 22. G.RM. Garrafl, The Early th:to~ ,~ R,~lio coni's use of HWT occurred. Alterna- from Farada~ to Marconi ([.tmdon: IliF 'Science Mu~um. 19q4), p. 78 tively any written historical document Notes and References stating that Marconi was using Hertzian 23. AA Campbell Swinh~n to W H Prcece, waves for wireless telegraphy may be 1. J.J. FaMe, A Histo~ t~ Win,less Teh:~rat,h~ letter dated ~ March 18t~6, Post thrice sought. For completeness, any such (London: Blackw~d, 1899), pp. 10-32, Records, ENG 231t~. Repn~luced in WJ. document, like a valid birth certificate, 13~143. Baker, A History ~!f the Marconi Company (Lond~m: Methuen, 1970), facing p. ~k~4.Camp- should be signed and dated by a reliable 2. IBM.,pp. 143-160. witness. bell Swintem's unterest m X-rays L~ dL~cus.'~ in 3. H. Hertz, t:M'tric Wa~rs, translated by this Bulletin hv Nell Brown. It appears that Marctmi contacted Italian D.E. Jones (~mdon: Macmillan, 18~3), pp. 9,';- Author'~ Addn~. s: 106. Government officials in late 1895 or early Sultan Qah~,s Uniz~'rsitu 1896 who showed no interest in his 4. IBM..pp. I07-123. ()man

Bulletin of the Scientific ln,~rument Society No. 46 (1995) II 19th Century French Scientific Instrument Makers VIII: Eug/me Ducretet (1844-1915) Paolo Brenni

Fig. l t I..'c,w 1~i. ~ctct ~t ,ore t; I h. rct.'t "Un ptomtn'r pour la rmho: Eu,¢i'm" Ducre- h't', Industries blectroniqms., 1970, off- prmt~. Fig.2 Oudin~ high f~,,,lu,,nt\v and hw.h zs,lta,ze trans,,met with a couph, ql: h'iden /ars and a swrk gap by Ducretet. fFn,m: A. Turpain, Les applications pratiques des ondes electriques ¢Paris: Naud, 1902), p. 214~.

One century ago this year the young interrupt his studies and was appren- time, in a Universal Exhibition. He was Italian Guglielmo Marconi (1874-1937) ticed to the workshop of Gustave awarded a gold medal, which repre- was carrying out his tirst important Fmment (1815-1865).: There, he devel- sented the first official recognition of his ~eries of wireless experiments in his oped his manual skills and improved his activity. The success was repeated in tamilv villa near [hdogna. h~.|av we scientnfic knowledge. A few years later, in 1881, at the International Electricity celebrate the centenary of the birth of 18¢~4, Ducretet opened his own workshop Exhibition in Paris. In the fldlowing wnreless. But if Marconi, the m~-called located at 21, rue des Ursulines. He decades Ducretet regularly participated 'radio magician', became a very tamous started with a small workforce to in the most important international public figure and a first-magnitude star manufacture a wide range of classical exhibitions, where he always presented in the tlrmament of inventors, we must physics research, teaching and demon- high-quality instruments.' Around 1880 remember that a crowd of ~ientists, stration apparatus. The beginnings were Ducretet, who needed more space for his technicians, engineers and inventors quite difficult becau~ of lack of money, firm, moved the workshop a few greatly contributed to the development but his reputation began to grow and he hundred meters away from its original of radio technology. In France, Eugene slowly became one of the instrument location to 75, rue des Feuillantines. Ducretet (Fig. I) was not only an suppiiers of several scientific and Around 1883 part of this road changed excelk,nt instrument maker, but one of academic institutions which were- situ- its name to rue Claude Bernard, so the French pioneers of wireless com- ated close to his workshop.' in 1866 Ducretet changed his address without munication. Ducretet married Amelie Vallat. They moving the location of his firm! had three children, Pierre in 1870, t-ugene Ducretet was born in Paris on 27 Laurence in 1872 and Femand in 1878. It is not p~vssible to mention here all the November 1844.: His father, Louis instruments which were made or pro- loseph, was a merchant in textiles. ]he In 1867 Ducretet published the first I~,,ed for the first time in France by family, originally from Savoy, had moved descriptive catalogue of his pr(~ucts. Ducretet. He was particularly interested to l',{ris at the end of the 18th century As it had be~n iml~vssible to complete in electricity, and ~veral studies, and a bex-au,~, of the I~r economic condition his ~h~ding, he was continuing his major part of his work were dedicated to of this alpine region. I)ucretet's early autodidactic education, by following this field of research In about 1878, the year,, clo~lv resembled that of many cour.~ at the 50rbonm, and the Colli'ge British electrotechnician James Wims- other French instrument make~ of hi's de Fnmce as an 'auditeur libre'? At the hurst (1832-1903) prol~se,d his induc- time. 18"~6-18"3q he attended a Betwtx, n ~me time he benefitted from his relation- tion electrostatic machine. In a few years primal' .v,'h~l in Rue St. Jacques, where ships with many illustrious physicists, this powerful generator became he showed an aptitude for mathematics, whom he considered 'ses maitres plut6t extremely popular not only in the geometry and drawing. At the end of the que ses clients', for deepening his know- physics cabinets, where it often super- I8~Os, owing to the precarious financial kxtge in physics and electricity. In 1878 in seded the older Toepler, Holtz and Voss condition of his father, he had to Paris, Ducretet participated, for the first machines, but also in the medical

12 Bulletin of the Scientific Instrument ~x:iety No..16 (ictg5) i I ~1 :P

Fig.5 Cmlletet"apparatus for liquef~jing ga~q,s by, Ducretet. (From: I. ]amin, Bouty, Cours de physique, Tome !i (Paris: Gauthier-Villars, 1886), IV ed., p. 304). Fig.3 E. Ducretet & L. Lejeune's mechanical interruptor for pou¢rful induction coils. The same apparatus is visible in the next Fig. head-on. (From: Turpain, op.cit., p. 69).

Ducretet was one of the first makers in France to improve and produce Tesla's apparatus. These high frequency currents were immediately applied to medicine because of their peculiar effects.' In France, the physicist and physiologist Arsene d'Arsonval (1851-1940) proposed the high frequency therapy (often called Dar~nvalisation), and the physiologist Paul Marie Oudin (1851-1923) invented a new transformer which was a modifica- tion of the original Tesla coil. ~The fashion for this kind of electrotherapy opened a very profitable market to Ducretet and other makers (Fig. 2). He manufactured and improved a large number of electrical research and measuring instruments as well as demonstration apparatus (galvanometers, electro- meters, wattmeters, large electro- magnets, rheostats, electric ovens, Crooks's tubes, etc.). Ducretet was aL,~ famous for his improved induction coils, for which he proposed new mechanical Fig.4 X-ray equipment made by, E. Ducretet around 1900. (From: G. and M.I. Pallardy, A. interruptors and better insulation Wackenheim, Histoire illustr~ de la radiologie (Paris: R. Dacosta, 1986L p. 492.;. (Fig. 3). His most powerful coil, which had a secondary of 136,(XX) windings (66 km of wire!), could easily pn~3uce cabinets where it was used both for when it was connected with a spark-gap electrotherapy and later for the produc- sparks of 80 cm and more." In 1895, the oscillating circuit, produced very, high di~overv of X-rays bv Conrad Ri~ntg,~a tion of X-rays. Ducretet was probably the voltages at high frequencies.: In 1891- (1845-19"23) found I~ucretet ready to first to introduce in France this type of 1892 Tesla demonstrated his experiments manufacture all the elecrical equipment generator, for example, he displayed at in the United States, as well as in lx~ndon necessary for pn~lucing the high voltage the 1889 Paris Exhibition a very large and Paris. Because of the strange and required" for the X-ray tubes, such as Wimshurst machine with 12 plates each spectacular effects of Tesla's current induction and Tesla coils and powerful 75 cm in diameter, its sparks were longer (strong electric sparks and luminous electrostatic induction machines (Fig. 4). then 40 cm. Late in the 1880s, the scientist effects), the Tesla transformer s¢~n He was in fact one of the first experi- Nikola Tesia (18,~-1953) ~ invented a new became the pii'ce de r~istance in every menters to produce the 'new kind of kind of transformer (Tesla coil), which, physics cabinet and electrical laboratory. rays' in France. He also invented a

Bulletin of the Scientific Instrument ~x~ciety No. 46 (1995) 13 ' [-

Fig.6 Laus~'dat'~ phatothe~t~lite made l~ Ducn'tet. ¢Fn,m: L'industrie [ran~;aise d~ instruments de precision, Catal~,,ue, Paris: Smdvcat d¢~ constructt'urs en instrume~lts d'ol,t,tue et dr" prt~cision, 1901-1~}2, 1980 rt'print bu Brieux. p. 98~. Fig.7 L),cr,'t,'t's early wireh'ss system. ~t r,,m: I. l~OiwX"e, 'tz~ teh'xraphie sans ill', La Nature, II sem., 1898. pp. 1-2).

special electrometer for studying the Chatelier (18~)-19~)." For the officer detector. In the late 1890s, Oliver Lodge electrical properties of X-rays. Unfiwtu- and engineer Aim~ Laussedat (1819- (1851-1940), Alexander Stephanovic natelv, before the dangerous effects of 1907) he produced one of the first types Popov (1859-1905), Marconi and many X-ra{'s were known, Ducretet's son of photothe~xtolites (Fig. 6). '' For the others were carrying out their expen- Femand (1878-1928) was often u,,~ as French navy he developed an electric ments. In 1897, after having heard of the 'patient' for these experiments and his signalling system and the loudspeaker Marconi's trials in La Spezia, Ducretet health was severely damaged. telephone, which had been prop(~ by began his researches in wireless)" lieutenant colonel Galliard. It is enough In the ,,ears between 1892 and about 18~ to study the pages of the various issues of He first achieved a wireless transmission Ducretet was associated with the Ducretet's illustrated catalogues to between his laboratory and the Panth~Jn engineer L&~n Leleune, who married appreciate the quantiW and the variety at a distance of about 400 metres. In spite Laurance, the daughter of the instru- of instruments which were marketed by of the countinuous successes of Marconi's ment maker. Ducretet collaborated with his workshop. Furthermore, the large experiments, which were mostly carried .~ome of the most important French numbers of b(n)klets and instruction out on the sea, Ducretet decided to try to scientists of his time. For them he leaflets printed by Ducretet's firm were communicate in the middle of Paris in improved and manufactured an impor- a witness to the importance of his activity order to determine the the influence of tant series of laboratory and industrial and ingenuity. '' On the other hand, man~, buildings and industrial electrical equip- instruments. In spite o(the fact that he illustrations of the catalogue were taken ment of the town. in autumn 1898, he was particularly interfered in electriciO,; from different scientific treatises and started his new experiments with his telephony and wireless telegraphy, i~e journals and represented instruments collaborator and partner Ernest Roger developed and produced all kinds of which were originally made by other between the top of the Eiffel tower and laboratory instruments.': Nevertheless, firms. '~ It is also possible that some the terrace of the Pantheon, a distance of the firm" remained quite small and apparatus were simply retailed or only about 4 kilometres. Their efforts were employed only a few workers. Among partly manufactured by Ducretet. the most original apparatus manufac- successful at the beginning of November (Fig. 7). Communication was clearly tured by Ducretet. was the Caflletet's At the end of the nineteenth century high pressure pump for liquefying ga.,~.s established and mantained. A year later Ducretet supplied many important lab- he transmitted between the Sacrd-Coeur (Fig. 5). This original clumsy apparatus, oratories in Europe, in the United States and the rue the Tolbiac, a distance of 7 which had been devi.,~,d b~' the indus- as well as in India, and he was a.,~,~x:iated trialist and inventor Louis Cailletet (1832- kiiometres. A few months later lieutenant with several prominent scientists. But the Camille Tissot (1867-1917) of the French 1913), was m~ified by Ducretet into a name of Ducretet is usually associated very efficient laborat~wy device.': He Navy, with a series of Ducretet's appara- with the beginning of wireless tech- tus, reached at first the distance of 22 marie the 'lunette pyrometrique' of nology in France, to which he dedicated Mt~,ur6 et Nouel, who were engineers at kilometres and then of 42 kilometres. The most of his time and energy in the last cooperation between Ducretet and the the Compa:.:me ,t~ fi~r~es de Ch~tilhm et twen~" years of his life. In 1890 the Commentry It was an optical pyrometer Russian Po~w 2'' was particularly fruitful. physicist Edouard Branly (1844-1940) In 1895 Poix)v, who was an instructor at which measured the temperature of a di~overed a peculiar property of metal- glowing mass by polarising and analys- the Torpedo School of Kronstadt, de- lic powder whose electrical resistance scribed and built an atmospheric dis- ing the emitted light." Ducretet also was severely affected by the presence of prt~uced and improved the electrical turbance detector. The apparatus was electromagnetic waves)" This led to his composed of a circuit with a coherer thermocouple pyrometer prop(~-,d by invention of the coherer (coh&eur) which the metallurgist and chemist Henri Le which was connected to a lightning became the first electromagnetic wave conductor (aerial) and the ground. In

14 Bulletin of the Scientific Instrument Society No. 46 0995) ,..t"

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Fig.9 Early electronics by F.Ducretet, a tetrode frequency changer of 1925. (From: G. Biraud, op.cit. (note 25), p. 156).

Fig.8 Ducretet-Popov's wireless receitw. The signals, were detected by a microphone. (From: E. Ducretet, La tOl~graphie hertzienne sans fil (Paris: Ducretet, 190?), p. 14). spite of the fact that Popov did not use after his other activitiesas an instrument nication and special navy equipment this system to send signals but only to maker, never really challenged the (periscopes, microphones, etc.). Unfortu- detect them, his instrument was practi- growing economic and industrial power nately in 1915 Pierre Ducretet (one of cally similar to a wireless receiver. For of companies such as Marconi or the Eugene's sons) died at Verdun. in 1918 about seven years, from 1898 onwards, German Telefunken. his brother Fernand had to abandon his Ducretet and Popov corresponded fre- scientific and technical activities. His quently and they also met twice in Paris health was declining due to the careless in 189q and 1900Y Their collaboration Eugene, together with his son Pierre, who had attended the military academy of exposure to the X-rays. Fernand died m gave birth to the Ducretet-Popov wireless 1928. But the activities of the firm apparatus (Fig. 8). n Thanks to this St. Cyr, continued their wireless experiments in the field of military application continued under the direction of E. system, it was possible to organize the Roger, who had collaborated with rescue of the Russian armoured battleship also. Around 1902 Ducretet developed a system of wireless 'underground' tele- Eugene since the late 18q0s, until 1919 Admiral D'Apraxine, which was trapped and finally under Rtg~ert Valette until in ice near the island of Hohland in the graphy, which did not need any kind of large aerial. After 1904 he collaborated 1931. During these years the firm Gulf of Finland during the winter of 1899- continued its .scientific activities and 1900. The two wireless stations (with 48 with the astronomer Guillaume Bigour- dan (1851-1932) in the first attempts of introduced in France many different meter aerials) at a distance of about 47 types of amplifiers, tuners and radio kilometres, worked very well between the wireless transmission of time signals from the Paris t~servatory to ships. (The receivers, and improved the technolt~y February and April in spite of terrible of thermionic valves (Fig. 9). In I'~31 the weather conditions. Popov described the regular service began in 1910.) Ducretet constantly cooperated with another Comt'a,~tlie Fran~+aise J'h,,msotI-Hol+sfota enterprise at the 1900 International ab.sorhed the old firm Ducretet. For Congress of Electricity in Paris, where pioneer of French wireless technology, Gustave Ferri# (1868-1'~32)Y many years radios, electric gramo- he publicly aknowledged that the success phones and esentually, televisions hear- of the enterprise was largely due to ing the trade name Ducretet-Th,mt~m Ducretet's efficient and reliable appara- in 1908 Ducretet, gravely ill, left the were vet3., i~pular in France. :~ tus. The Russian government awarded direction of the firm to his son Femand the Parisian instrument maker with the and to his associate E. Roger. Eugene Order of St. Stanislas. Ducretet died on 23 August 1915. In Unlike Marconi, all of whose energy. 1910 the Ducretet's worL~hop pn~luced ingenuity and financial rt.~urces ~ew the radiogoniometer (compas azimutal completely devoted to wireless develop- Ducretet propt~d a large number of hertzien), which had [,ten developed by ment, Ducretet did not have the neces- circui~ and apparatus related to wireless two Italians, the engineer Ettore [k'llini sary financial supl~wt for undertaking technology such as improved coherers, (1876-1943) and captain l'osi. ThanL,~ to ve~' large .~ale experiments nor could he relays, spark-gaps, induction coils, flat- this instrument, which had two ortho- negk'ct his activity as instrument maker spiral transformer, interruptors and gonal moveable aerials, it was possible His interest was probably more ~'ientlfic aerials, which were carefully described to locate the situation of a wireless than commercial and he did not have the in a series of articles and btn,klets. These transmission stationY Finally, the Du- determination nor the possibility to devices, which were often patented by cretet's firm also developed some of the organize and rule a large wirele,~s Ducretet, were successfuly tested and first radio beacon automatic apparatus. company. Ducretet was to the earlier used on many ships and stations on During the First World War the produc- decades" of the French 'third republic' land. But Ducretet, who also had to look tion was devoted to military, commu- what Heinrich RuhmkorfF" had been to

Bulletinof the ScientificInstrument Society No. 40 (19~5) 15 the Second Empire, as they have several teldgraphie hertzienne sans .ill (Paris: E. (with Lqeune), 'Robinet pour r~ipients things in common. They were excellent Ducretet, 1904). destin~ aux gaz comprimtSs ou liquefi~', and skilfull makers and they were Notice complbnentaire aux guides prati- 123 (1896), pp. 810-811. particularly interested in electrical tech- ques de E.Ducretet (Paris: E. Ducretet, (with ~), 'lnterrupteur i mercum nology. Furthermore, both men contrib- 1906).= pour les fortes bobines de Ruhmkorff', uted to the introduction in France of 124 (1897), pp. 1342-1344. several instruments which had been Some other instruments are described in: 'Poste r6cepteur pour t~ld,graphie sans invented abroad. Like Ruhmkorff, Notice sur la machine pneumatique ¢t de ills', 126 (1898), pp. 1266-1268. Ducretet was able to transform a crude compression de E. Ducretet (Paris: de Stalin 'Enregistrement des ddcharges prototype into an efficient, useful and et Labour, 1873). ~lectriques atmosph~riques', 126 (1898), elegant instrument. An examination of Notice sur la table d'Amplce nu~!fi~ par p. 1743. Ducretet's papers help to understand Berlin (Paris:Stalin et LabourS, 1874). 'Tel~graphie hertzienne sans ills entre la how intense his research activity was. Notice sur l'emploidu microscope polarisant tour Eiffel et le Pan~'0 127 (1899), Furthermore, from the large amount of de Nodot (Paris: de Pelluard, 1877). pp. 713-716. lettersfrom scientists and inventors,~m Notice sur un poste tdl~phonique avec (with Popov), 'Application directe d'un newspaper and scientificjournal articles, sonnerie atcrtisseur,contrOle d'appel (Paris: rtScepteur ~lOphonique ~, la t~l~graphie it is easy to see how he kept himself well Pelluard, 1880). sans ill', 131 (19flO), pp. 1296-1298. informed about recent technicaldevelop- Instruction pour l'usage et l'installationdu 'T~l~phonie sans ill, par la terre', 134 ments. Ducretet's scientificcuriosity and tdldphone haut-parleur et des tableaux- (1902), pp. 92-93. technical skillmade him one of the most combinateurs R.Gaillard (Guises. de BaM, 'Dispositif de reglage et d'accord pour les interesting figures in the history of 19th 1901). r~epteurs des postes de t~l~graphie sans century French scientific instrument Notice sur It'stransformateurs dlectrolytiques ill',145 (1907), pp. 171-172. making. Ducretet became Chevalier de la des courants alternatifsen courants redresses I,f'gion d'Homwur in 1885 and his son ondulatoire,systi, me O. de Faria ~ circulation Fernand Ducret~ Fernand in 1927. On 25 November 1970 a automatique du liquide (Montreuih de commemorative plaque was set on the Carbonne, 1907). (with Roger) Notice sur les courants de house at the 10, rue Pierre et Marie Curie, haute frdquence et de haute tension, where Eug6ne Ducretet died. Its text In the Journal de Physique thdorique et risonateurs de M. le Dr. Oudin, applications reads: appliqu~ midicales et exp~iences classiques (Paris: En cette maison est mort 'Sur un rc~othome liquide a direction Ducretet et Roger, 1909). EUGENE DUCRETET constante', I s~rie,4 (1875), pp. 84-85. 1844-1915 'Galvanom6tre universel', II s&ie, 2 In the Comptes rendus de I'Acad~raie des Tra~aux sur la haute frdquence et sur (1883), pp. 556-558. Science les rayons X (with L. Lejeune) 'Notice sur les (with Roger) 'Appareii pour la r~ception Conception ef rialisation du premier exptSriences de MM. Elihu Thomson et de l'heure A domicile et A bord des disposit!f francais de T.S.F. (1897) Tesla', Ill s~e, 2 (1893), pp. 126-129. navires par la t~i~graphie san ill', 151 R~ception au son. Syntonie par rf,smrance (with L. ~) 'InterrupteurA mercure (1910), pp. 53-55. pour les fortesbobines de Ruhmkorff', Ill (with Roger and J.Paillet) 'Nouveau In the Con.,a'rt~atoire des Arts et Mr'tiers in s~rie, 7 (1898), pp. 336-338. proc&l~ de d6~lectrisation des mati~res Paris are kept several instruments made textiles au moyen des courants by Ducretet, and many others can be In the Comptes rendus de I'Acaddmie des ~lectriques de haute fr~quence', 152 found in several European and American Sciences: (1911), pp. 583-585. mu~ums and collections. Ducretet's 'Sur une nouveile lampe ~iectrique', 87 (with H. Lioret and Roger), 'Dispositif wireless apparatus are much valued by (1878), pp. 1081-1082. d'enregistrement A distance d'une trans- k~av's vintage radio collectors. 'Perfectionnement apport~ A la iampe mission tei~graphique sur cylindres ou ~iectrique d'Harrisson', 88 (1879), disques phonographiques', 152 (1911), pp. 340-341. pp. 1476-1477. Essential Bibliography 'M(~ification de l'interrupteur de Neef (with A. Taulaigne and Roger), I~mr bobine de Ruhmkorff', 92 (1881), 'Enregistrement graphique des radio- Ducretet wrote many articles and notes p. 1228. t~l~,grammes', 158 (1914), pp. 112-113. for different scientific journals. It would 'Sur un galvanom6tre universel sans be too long here to give a complete oscillation pour la mesure rapide de Pierre Ducretet published: bibliography. Thus l have only listed courants de grande intensitts ou de haute some of the most interesting ones, and tension', 97 (1883), pp. 254-255. Traitd ildmentaire de tildgraphie et de those which appeared in the Comptes 'Sur l'~talonnage des galvanometes', 97 tdif'phonie sans fil (application militaires et Rendus de I'Acad~;mie d~ Sciences and in (1883), p. 1477. maritimes) (Paris: Chapelot, 1903). the Journal de Physique thdorique et 'Nouvel appareil pour recueillirla neige appliqm;. carbonique', 99 (1884), pp. 235-237. Notes and References 'Galvanombtre A aiguille astatique', 99 The most important apparatus for (1884), p. 6O5. 1. The most important biographical sources Ducretet's wireless transmission are 'Appareil destir~ A v~riiler la fabrication are:. B. Ducretet, 'Eugt~ne Ducretet 1844-1915', described in: des amorces ~iectriques', 102 (1886), Ondes courtes information, 18 (1971) (offprint); La tHt;~,,raphie hertzienne sans fil (Paris: E. pp. 1158-1160. B. Ducretet, 'Un pionnier pour la radio: Ducretet, 1901). 'Enregistreur m6chanique et automatique Eug#ne Ducretet', Industries ~lectroniques, Guide pratique de h;h;graphie hertzienne sans des signaux transmis par ies t~lC~graphes 1970, (offprint); R. Franc, £ugine Ducretet f/I (Paris: E. Ducretet, 1901). et its pro~'cteurs optiques', 105 (1887), (Paris, 1964), 'Eugthae Ducretet eties d~,buts Addition au guide pratique de tdldgraphie pp. 664-067. de la t~K~graphie sans ills', Diligence d'Alsace, 49 (1993), pp. 5o-68. in 1969 Bernard Ducretet, hertzienne sans fil (Paris: E. Ducretet, (with Lejeune), 'Creuset electrique de Eugene's grandson, gave to the archives of the 1902). laboratoire, avec aimant directeur', 116 Acad~Smie des Sciences in Paris five boxes of Seconde addition au guide pratique de (1893), pp. 639-640. documents, letters, drawings, catalogues,

16 Bulletin of the Scientific Instrument Society No. 46 (1995) newspaper articles related to the work of 10. J. Laffargue, 'Bubine de Ruhmkorff A 18. An insulating tube ctmtainmg a metallic Eugtne Ducretet. In 1993 he gave the rest of ~,cincelle de 80m de Iongueur', La Nature, I powder (silver, c(~er nickel, etc.) between the firm's archives to the C.¢ntre de Documenta- sere., 1901, pp. 109.110. two electrodes has normally a resistance in the turn en Histoire des Scwnces et des Technique order of a megaohm A train of electro- (CDHST) du Conservatoire des Art ct M~tiers. 11. Since the late 19th century Ducretet (and magnetic waves produces the cohensation of This material is highly interesting and should many of his colleagues) exhibited their newest the powder whose resistance then suddenly be carefully studied. I am very grateful to M and more interesting instruments at the hlls to a few hundreds ohms. A mechanical Bernard Ducretet, who gave me useful Expositam de la Socitt~ franfaise de physique, shock to the tube re-establishes the high information concerning his grandfather's which normally took place at Easter time. See resistance. Branly often used Ducretet's instru- activity. the Bulletin des s~ances de la Socitt# franoaise de ments. Among them, in Branly's collection at Phys~ue. the institut Catholique in Pahs one can admire a 2. See: R Brermi, 'Paul Gust.ave Froment', very large electromagnet made by Ducr~et. Bulletin of the Scientific Instrument Society, No. 12. See: L. Cailletet, 'Recherches sur ia 45 (1995), pp. 19-23. lklu~action des gas', Annales de physique ¢t de 19. A few years earlier Ducretet had intro- chimie, s~rie V, 15 (1878), pp. 132-144 and duced in France the apparatus for reproducing the observations of Heinrich Hertz (1857-1/4~4) 3. In fact the Sorbonne, the Colltg,e de France, TBsandier G., 'La liqulaction des gas', La the g-cole Polytechique and the I~cole Normale Nature, I sere., 1878, pp. 102-106 and 152-154. concerning electromagnetic waves. Supdrieure, were all concentrated in a quite small area of Paris. Docket's workshop was 20. The French prefer to spell it as P(~:n#f. almost at the centre of this area. 13. See: LB., 'La lunette pyromtStrique de MM. Mesur~ et Nouel', La Nature, 1 sere. 1889, pp. 139-140. 21. Many letters of the Ducretet-P(~off are 4. He was classed a 'listener' with no official kept in the archives of the Academic des Scu'nces obligations. in Paris (see note I). 14. See:. H. I.t Chatelier, 'De la mesure des 5. Among the most important ones we tempthratures ~levLSes par Its couples 22. This apparatus with a special coherer did remember Paris 1878 and 1881 (electricity ~lectnques', Iournal de phys,que thf,orique et not have any relay and the signals were exhibition), Amsterdam (1883), Antwerp apphquie, II s~-ie, 6 (1887), pp. 23-31. directly detected by a telephonic microphone. (1885), Melbourne (1888), Moscow (1891, hors Ducretet was also manufacturing an improved concou~), Paris (1889), Chicago 1893, hors 15. Laussedat was director of the gcole version of the Popov's atmospheric discharge concours) Brussels, Paris 1900, San Louis Polytechn~lue and Own of the Consenwtoire des recorder. (1904), Lit,ge (1905), Milan (1906, member of Arts et Mdtiers. He was a pioneer of the jury), London (190~, member of the jury), pho~opo~aphy. 23. In 1903 Ferri~ created the wireless station etc. on the top of the Eiffeltower. See M. Amoudry, 16. I~cret~ published several catak)gues: in Lt gintral FerriC: et la naissance des transmission 6. Tesla was born in Croatia, at the border of 1867, in 1870, in 1879, in 1880, in 1888, in 1893 et de la radiodiffusion (Grenoble: Presses the Austro-Hungarian empire, but he moved (Docket et Ltwune), in 1900, in 1905 and in univecsitaires de Grenoble, 1993). very soon to the United States, where he spent 1912 (E Ducretet et Roger). Some oC them are the rest of his life. recorded in RG.W. Anderson, J. BurnetL B. 24. Bellini, Tosi, Compas Azimutal Hertzien Gee, Handlist of Scientific Instrument-Maker's Bellini e Tosi, pour la navigation en temps dr 7. A typical Tesla's coil transformer could Trade Catalogues (National Museum o~ Scot- brume (Paris: Bellilqi e Tosi, 1910). produce voltage of several hundreds of land Information Series No. 8, Edinburgh, thousands of volt with a frequency of about 1990), p. 53. An important collection of 25. Many Ducretet and lhom~m-Ducretet 1 megahertz. Ducretet's catalogues and leaflets can be wireless and radio apparatus am illustrated found in his archives at the Acadf,mie des in: G. Biraud, R. Foster, The RadJo and TV 8. Tesla's high f~lm,nc'y currents do not Scaraces and of the CDHST (see note l). Among Collector'sGuide Book (Fontenay le Comte: G. produce an electric shock on the human body. these documents there is a large handwritten Biraud, 1988), French and English bilingual Because of the 'skin effect' they slip on the album in which Ducretet systematically listed edition. surface of the body. all the publications of his firm. 26. See P. Brenni, 'Daniel Heinrich Ruhm- 9. In fact Oudin proposed an auto- 17. This was a current practice dunng the korff', Bulletin of Scient!tic Instrument Socu'tg. transformer which was composed of a single 19th century. See R Brenni, 'The Scientific No. 41, (19~4), pp. 6.8. multi-winding spiral of thick wire. The lower Instn.nent Makers Illustrated Catak~gues' in pan of it acted as a primary coil and the upper C. Blondel, E Parent, A. Turner (editors), Acres 27, All these b~x)klets were reprinted in Pans part as a secondary one. Ducretet also used du Vile colloque d'histoire des instruments in 1981. this kind of transformer in his wireless scientifiques (London: Turner, Paris: CSI, apparatus. 1988), pp. 169-178. Next to come: Deleuil.

I @AIII&4MIn 0¢' ~.D~. - -,* NlI£11qlON(I Oqlu' r.N£&Pll, Og)E, WIRELESS TELEGRAPH i.~,, b. "~' It was not only the instrument-making firms that cashed in on the burgeoning interest in wireless telegraphy, but also large department stores such as Gamages of Holbom, London. This illustration is reproduced from their Christmas Catalogue of 1913. Such items are now difficult to find partly because of their delicate construction, but also because they were cannibalised by the post-WWl generation of radio enthusiasts.

Bulletin of the Scientific Instrument Society. No. 46 (1995) 17 Astrolabes and Electrotypes: An Enquiry

Sma~ ~lbot

Fig.l ApF~zratu~ fi,r eh'ctn,tvpm¢. ~From - --:-; "

Fig.2 Apparatus fbr gold and sdz,er platmx,. Origins of Elettrotyping Process (From Guilh'min, op. c#t., p. 916, Fig. 560').

Electn~,.'ping (Fig. I)' was a revolution- arv process discovered by George the current is switched on the copper Fig.3 Mould for electn)typmg a round Richards Elkington (1801-65) and his sulphate solution decomposes and object and the oase reproduced by this cousin Henrs' Elkington (c.1812-52) in deposits over the entire surface of the method. (From Guillemin, op. cit, p. 913, Birmingham," England, in the 18~h and metallised mould. Depletion of the Figs. 557 and 558~. -R~s. The family were gilt-toy makers in solution is compensated by having the the late eigtet-/nth and earl'," nineteenth desired plating metal (gold, silver or copper) finely cut in a porous bag 3. Gildering and silvering metals by centuries, and G.R. Elkington was Henry Eikington: No. 7496 (1837) apprenticed to his uncles Josiah and replenishing the amount of metal George Richards. ab,,~rbed on the mould. The concentra- tion of the solution in the bath remains Chemical processing and applications constant, thus the desired metal can be in detail. George Richards Elkingt(m and Henry termed a 'soluble electrode' in this Eikmgt~m conducted extensive research gah'anic process. 4. Coating metals with zinc and co. by into gilding base metals which led to G.R. Elkington and Oglethorp Wa- their historic .series of British patents. The kelin Barratt: No. 7742 (1838) electn,plating technique~lFig. 2) di~ov- Extracts from the Elkington Patents ered and patented No. 8447 in 1840 is (i) Metals are coated with zinc to The following patents-" are the foundation possibly the greatest advance in electro- prevent their oxidation. This is espe- chemistrs', and the process of electro- on which the Elkington Company built cially necessary when dealing with factories in Birmingham, Liverpool, typing is the ingenious by-product. copper positive or negative moulds, London and Dublin: i.e. electroforms. The Eikingtons di~overed that electric current not only pn~tuces movement - it 1. Gilding by G.R. Elkington: No. 7134 (ii) Improvements to the ancient heats, melts anti volatl.,~e.smost refractory (1836) technique of semile For - 'semiloring' metals and other substances. They in English usage. By applying a fine observed that the negative electnn.tes of Gilding copper, brass and other coat of zinc to copper and/or brass ~et cell batterie~ became covered with metals and alloys by means of and heating the metal until the 'colour ~erv fine layered deposits of copper l~tash combined with carbonic acid of gold' is obtained. The density of which, when peeled away, repn~iuced and a solution of gold. The gilding gilding required could be controlled m minute detail the surface in~riptions, can be given a 'dead appearance' by by the amount of zinc used and the imperfections and undulations in rata Clio means of the acid 'deading acqua intensity, and time of heating. form, that is, a perfect mould cast. By fi~rtis" used by brass founders. Ac- .~ub~tituting the batters, terminal with a cording to (~.R. Elkington, "The 5. Plating metals by G.R. and H. mould coated with a conductor - if not a beauW of the result depending on Elkington: No. 8447 (1840) metal, this could I~, formt~ from wax, clean'rinsing at every stage and the pla~ter or gutta-percha and the surface Object then pas,,~xl at once into the Plating metals with a certain solution metalli~t. Powdered plumbago, bronz- liquid to be gilded". of gold, silver or copper with the ing Im~wder, or a ~dution of silver nitrate application of a galvanic [electric] and alcohol, were the preferred conduc- 2. Coating metals by Henry Elkington: current. The description is as follows: tors. tA'hen a wet mould is then exposed No. 7304 (1837) "Two concentric cylinders clewed at to fumes of hydrogen sulphide, a the tn,ttom: the outer one in glass and blackened coating of silver sulphide is Gilding by a sadution of gold and the inner one of non-porous earth- formed which is an excellent conductor. mercurv. The gold will alloy with a enware: the space between them Ihe blackened mould is suspended in a slight c~ating of mercury and'will turn forms a Cell into which is poured copper ~lution of suiphuric acid into a greenish bronze colour. Put the sodium chloride. A zinc cylinder is which a tinc o,'linder is suspended, thus article in a solution of mercury and imme"rsed with a wire and made to forming the negative l~de of the battery. potash and when uniformly white, bend over & dip into the inner vessel The mould is lowered into the copper heat over a clear fire until all the which contains the solution of gold, sulphate .~dution by a wire and thus the mercury is expelled - this is a process silver or copper. Thickness of the apparatus is a simple battery, and when called 'Heightening'. plating will dtTend on the length of

18 Bulletin of the Scientific Instrument S~iety No. 46 (19q~i) Fig.4 Vu'w,!~' Oudrv's workshop fi,r cOt,l,er Fig.6 Throne of electro~pe of Ar,emu, plating. (from Guillemin, op. cit., p. 920, astrolabe for Phi~lip If. fig. 563).

Fig.5. Eh'ctr,,tyl,e of Arsenius a.erolab,'.ti,r Phi/lip II of Spain. In British Mu.c~'um.

Fig.7 Electrotype of Science Museum version of the Phillip II astrolabe showing weakened soldered mater. Fig.9 View of ~me astrolabe sturwtng the dented hollow form of the mater.

the current time applied and the force 0 of current. Zinc & Tun may also be museum directors and industrialists of gilded by this process". A variant the day from Belgium, England, France process detailed the process of coat- and Germany. The declared aim of the ing an iron object with copper. committee at this first meeting in

,,, ~ r, February 1875 was to endorse a Royal The Company had showrooms in Regent Fig.8 Electrotype of planispheric astrolabe Commission on Scientific Instruction Street, London and New Hall Street, by. lbrahim /bn Said of Valencia. in Science with regard to the creation in ~mdon of Birmingham. In 1842 the Company Mu~um. a Science Mu.,;~um. The loan of great became Elkington, Mason & Co when original scientific masterpieces from they were joined by Josiah Mason, a around the world was a great opportu- with an equal and regular deposit of successful pen-nib manufacturer. This nity for copying .~.~me exemplary, exam- copper. A sealed mould was devised partnership was terminated in 1861 and pies. The committee sanctioned, at which had a separate pierced lead the Company reverted to Elkington & considerable public expense, three Co. 'colander' form (Fig. 3) sized so that the electrotype copies of the great astrolahe interval between the mould and the of PhiUip II of Spain bv Walter Ar~,nius Licencees and Technical Improvements colander was the desired thickness. This of 1~ (IC 231). This was a massive produced casting of equal thickness and undertaking bearing in mind the extra- strength. The reproduction of enormous The Elkingtons succeeded in protecting ordinary inscriptions and size of the electroforms was limited by only the their patents, buying out all their rivals in instrument which is 5~) mm (23 inch¢~) ingenuity, of mould and coiander con- England. They granted manufacturing in diameter, 7"70 mm high (~)t~, incht~l struction. licences to continental companies, the and 40 mm (ltd, inches) width Invoiced most prominent being Christofle of Paris at a c~v~t of £.32 each by Elkmgton & Co and C. Haas of Vienna. The companies The period of fifty years between 1850 on 13 February 1877. Tht.'se ~pectacular soon arranged access to masterpieces of and 1~}0 is considered the golden age of electrotypes now rt.~ide in the British the applied arts held by the la~uvre, the electrotyping. Popularity tell away dram- Museum (Figs. 5 and 0), the .c~-ience Kunsthistorische Mu~um in Vienna; aticallv at the beginning of the t~'entieth Museum (Fig. 7)' and the National while in England Eikingtons began century as the huge cost of retaining and Mu~,um of Scotland. The gilding ech,~-, copying the South Kensington renewing annual licences with the the 'dead appearance' mentioned in G.R. Museum's notable treasures (later the participating museums outweighed pub- EIkington's 1836 patent. ]'he rt.~ult was a Victoria and Albert Mu~um). ]'here lic demand. triple tour de force in eloctrotyping and was vast commercial potential in market- gilding that imitates the original in ing these perfectly reproduced and The Astrolabe Image Madrid's Mu.~'o Arqueologicn Nacional.' finished electrotypes to a public longing to possess these cultural icons of the The apex of electro-copying of astrolabes The electrotype of the famous lslanuc applied arts and sciences. would appear to have occurred with the planispheric astrolabe of Ibrahim lbn Special Loan Collection of Scientific .<,aid of Valencia, dated i(~ (IC 121) The challenge in reproducing three- Apparatus at the South Kensington from the Staatli.~he Sammlung in Kassel dimensional objects was to obtain an Museum. In 1875 a ltXbstrong commit- was purcha.,~l by the South Kensington equal thickness in all parts of a mould tee comprising eminent academics, Mu~um (Figs. 8"and ~)' for 10 (;uineas

Bulletin of the Scientific Instrument S~ety No. 46 (1~5) 19 .¢~t...'J ~.

Fig.ll View ,,f msid," ,~" mah'r i![ same astn,labc.

Fig.12 Stem,graphic pn,B,cti,,n ,m hl,k ,~f mater of ~me astrolabe. Fig. I0 Orl~,,m,d l)e,~,n,h,'n's astr,,I,1t~'. Fidl t:ront,d ~'i,'w. I11 Brltislt ,~,lus'um

Fig.15 httrl,,lt," 'tt,hl,' r,'h',,f .~am,' dec/r,,- type astrolabe. Fig.14 l;,':~' 4,÷ m..fi of m,lt,'r o.t ~,lme ,'hvtn,type a~tr',hlbe stli,win~ c,,rn~i,,n ,!f Fig. 13 tl~,'"':~'l'~ IV.~,,,lw,c. ,1.tn,i,ll,," centre axis. (Author's colh'cti,,nL shOiCln¢, bhlnk b, lCk ot ntater. CAIdtl,,r's colh'(tlot!).

from Elkington & Co. The dimensions art, with the instruments of astronomy and has a beautiful, even pale, bright brass 21hl mm height, lSr5 mm diameter, and mathematics". When Spitzer died the colour with a fine determined hand to the ~1 mm width The ek'ctrotype has been purchase of his whole collection as a inscriptions. damaged within the last five years and national treasure of France was consid- the indentation dearly ob~.,er'v'ecl at the ered, hut eventually it was sold by The electrotype was acquired by the ba,,e of the mater confirms that this is auction in 18~2 in over 3(X)O lots. In author in ]Oq3 in a West London indeed a ht~llo~ electro-form. retrosl~'Ct ~,me of the catalogued articles salesrtx~m. Compari.~m with the pale have, with modem scrutineering tech- brass original indicates that this sped- Descrolieres Astrolabe: Original and niques, proved to be of doubtful men appears to have been made for Electrotype Compared authenticity. decorative purposes as many of the features differ from the original, such as I-he De,,crolieres a~trolabe (IC 208), The IX'scrolieres astrolabe is modelled the following: (]) There is no rear 330 mm height, 2~1 mm diameter and after an original design by Arsenius as is stereographic projection although the -5 mm depth, wa~, acquired by the British e~ident in the distinctive and elegant rear astnmomical alidade is true in every Mu~t.um in 1893 from t'he Spitzer "tulip' form rete. [n~ri[~'cl on the throne feature (Fig. ]3). (2) The inside of the Collectttm. An Au,,trian dealer, Fr~"~lt',ric 'Adrianus Descrolieres fecit Lutetiam mater (Fig. 14) is identical to the Spltzer (181~-thl), established himself in 15~1' which features Arsenius distinc- impression of one of the km~,~ plates of I'ari, in 1~2 and supplied many new tive reclining male and female faun the original 'Tropicus Aequinor lalis pro collt~:tor,, of the industrial applie~J arts. figurines supporting the shackle shield Elevatione Poll 39'. There are no plates. bpit,'er'~ considerable influence created a which contains a 20 mm compass recess (3) The front alidade has a pair of raised taste for the collecting of arms and (Fig. I0). The original has three plates: sights with abrasion marks to the tenth armt~ur, and ,~-ienttfic in~,truments. It is two featuring stereographic projections unit of the 'Hora Ortus' scale echoing onl~ in .qpit/er% own ctdlection, and in and one of (~qua[ hours. The inside of the th,~e marks at exactly the same location ¢t,lit,cti(,n,, influenced by him, that mater (Fig. ll) is beautifully engraved as the British Mu~um's original. This m,,trument~, appear in am.' number as with a fine qmldratum nauticmn or 'R~sa bears witness to the infinite detail pre~iou~lv they had hardh,' been con- de] Vent]' featuring wind directions and I~lssible with the electrotype process. '~idered. "It was ntwes~arv to be like M. points of the compass. The reverse of the This is also demonstrated by the ~pit,,t'r, a virtuo~, in the old ~'n~, of the mater has a superb stereographic projec- intricate electrotype of the 'tulip' form term, to imagine mt,unting a showcase tion of the celestial globe (Fig;. ]2). This of the fete (Fig. 15). In all other respects

20 Bulletin of the ,%ientific Instrument ~lcieW No. 46 (19'~5) Fig. l~4 th',tr,,tyl,c (,t the Greenwich Vah'n¢ia mariner's astn,labe.

Fig.16 Eh'ctrotvl,,' ,!l Met:ker ,lstr,,notnic,iI Fig.17 fScctr,,tql,C ot Alct:/~cr a.trom,,:,,fl oh,ok: front view. ch,ck: rez~se view. the dimensions are faithfulto the original reproducing this astronomical master- Catalogue and Marketing as is the shiny quality to the gilding. (5) A piece was justified by demand. The telling sign of this copy is the formation clock is 185 x 115 x 300 mm (7~/~ x 4~/2 "Examples of Which Copies may he of verdigris (Fig. 14) around the central x flY4 inches) high. The quality and supplied by the Electrotypists". axis: the gilding and zinc coating have finish of electrotype copies varies con- worn at this point so the copper form siderably because of the various options The i~)pulanty and extent to which the underlying is corr(~ing. (6) This electro- on the desired gilt or electroplate silver. European museums and individuals type was manufactured prior to the This copy (Figs. 16 and 17) is in the were prepared to make available ong- British Museum's acquisition in 1893 as Science Mumum in L,mdon, and the inal applied works of art and science to the Museum has not relea:sedthe original rough cast quality, is evident on close be copied on a vast .scale is evidenced at any time. This is therefore a fine inspection. However, a 'Cia~ l' gilded by large inventories, such as Reproduc- decorative shorthand copy that would electrotype Metzker with clock mechan- ti~,ns in Metal 1852-1882 in 4 Paris." The appear to predate the Museum's acquisi- ism is today a most impressive and full title of the one penn)' 18~'~ tion in 1893. desirable facsimile. Catalogue gives an insight into the philanthrophic ideals of the lime: Price The Astronomical Clock of Jeremias List t~ ReT,roductions c~ (_)bjects ,,f flu" Metzker of Augsburg The Greenwich Valencia Mariner'~ Applied Arts sele,t,'d fr,,m the South Astrolabe Kensington Museum and various other This elaborate Ti~huhr, dated 1564, is Public and Private Colh'ctions. Prt~tuced probably the most famous original South .fi,r the u~ c~ Schools ,ffArt and h,r Gcm'ral Purposes (:f Public Instruction. Thi~ German sixteenth century astronomical Dating ~,m c. 1588 (Fig. 18), this is catalogue lists more than ~}(1 oblects of clock. It is in the collection of the possibly of Portuguese origin and was which approximately half were electro- Kunsthistorische Museum in Vienna.: It discovered on Vaien~;ia Island off the types of great variety. The ek,ctrotypes is al~ thanks to the ingenuity of the southwest coast of Ireland in 1845, and were obtained from: electrotyping technique the most famous was given to the South Kensington electrotype of any scientific clock or Museum probably in the late 1864k ~ Its instrument, and copies are regularly dimensions are 178 mm diameter x I. The Museum - presumably if in st~'k. referred, in hopeful expectation, to 17 mm width (7 x ~/4 inches). The museums and auction houses. In 1865 electrotype has a Science Museum 2. Elkinghm & Co. - both fn~m their the company C. Haas of Burgstras~ 57, inventory number (1876-1032), which i.x)ndon and Birmingham brancht.'s. Vienna VII, had acquired a licence from confirms that the astrolabe was copied the K & K Austrian Museums of Art and for the Special ~an Collection of 1877. 3. Franchi & Co., 15 Mvddleton St., Industry, and commenced a large series The original was transferred to the Clerkenwell. of electn)type copies of objects from the National Maritime Museum at Green- Imperial Collections. The clock appears wich in 19.54 (inventory no. A.55/54-13), All items wen, available in fl~ur alter- in the catalogue for the first time in 1865 (NMM4), and the electrotype remains in native states: for the sum of ll0 fl (guilders) without the Science Museum as a visual reference the clockwork, and 150 fl with the in the Navigation gallery. The co[ouring mechanism. In 1868 the price was is a fine dark green patination with the 1. Gilt - price IiX~",. increased to 152 fl - a 30% rise appears casting imperfections of the original to indicate that the complexity of vividly detaik,d. 2. Parcel gilt - price 100%.

Bulletin of the Scienlific Instrument Society No. 46 (1995) 21 Fig.20 Electrotype of model of lunar crater "Erastosthenes', dated 1851 (Science Museum, London).

Fig.19 Electrot~,e ~. "trademark.

3. Silvered and oxidised - price 5(P/o. size. This was exhibited in Class X of the 5. Science Museum inv. no 1877-8. Great Exhibition and is a superlative 4. Electro-copper, bnmzed - price 30% of tribute in miniature to an astronomer's Class 1 cost. observation of the lunar landscape 6. Anthony Turner, Early Scientific Instru- ments: Europe 1400-1800 (L(~don: Sotheby's, translated in such innovative fashion by 1987), Appendix A: 'A Note on the Collecting The last category was the most affordable the newly discovered art of the electro- of Sdentific Instruments', pp. 277-278. and the copper was given a bronzed type. appearance by a brush dipped in a solution of acetate of copper and Acknowledgements 7. E. Neumann, 'Die Tkschuhr des Jeremias ammonia. ~° Metzker yon 1564 und Ihre nachsten verwand- ten', lahrbuch der Kunsthistori~hen Sammlun~en The author wishes to thank the following in Wien, vol 54 (Vienna, 1964). Trademark in the preparation of this paper: G. UE. Turner of Imperial College; David An oval embossed copper cartouche 24 x Thompson and J. Leopold of the British 8. Alan Stimson, The Mariner's Astrolabe (Utrecht, 1988). 18 mm (Fig. 19) was attached to the Museum; Kevin Johnson, Assistant Cura- plinth of many copies: 'V.R * Depart- tor of Astronomy at the Science Museum; ment of Science and Art * Elkington'. Leslie Lewis of BJS Co. Ltd., London; and 9. South Kensington Museum, Index to the Patents Section of The British Library Electrotypes Acquired 1852-1883, in 4 Parts A Lunar Electrotype dated 1851 (see note 2). (London: HMSO, 1886).

Notes In this brief study mention should be and References 10. Price List af Obiects ~ Art : Catah~ue 18.59 made of the earliest verifiable electrotype (V & A Collection: South Kensington, 18~). encountered during the author's 1. Figs. 1 to 4 taken from A. Guillemin, research. It was ordered by H.M. Electricity and Magnetism, revised and edited Commissioners for the Great Exhibition bv S.E Thompson (London and New York: All photographs were taken by the Macmillan, 1891), pp. 902-923. of 1851. ]t was a superbly detailed author, Figs. 5, 6, 10, !1, 12, with miniature lunar landscape (Fig. 20) permission of the British Museum, and measuring just 120 x 90 mm (41/.~ x 31/: 2. The Bntish Library, Patents Section, 25 7, 8, 9, 17, 18, 19, 2(), 21 with permission Southampton Bldgs., Chancery. Lane, London of the Science Museum inches) made in 18~l, according to the WC2A lAW. dt.~riptive label, by a Henm' Blunt of Shrewsbury in Shropshire. 1-he crater in 3. Science Museum inv. no. 1877-7. Author ~ address: reality is 2~ miles in diameter. The whole 10 Danebu~. is framed within a lidded mahogany box 4. ~ RT Gunther, Astn,labes ,~ the World 9 St. Quintin Gardens onh," 140 x l(X)mm (5~/.~ x 4 inches) in (Holland Press, 1975). London WIO 6AS

22 Bulletin of the Scientific Instrument Society. No. 46 (1995) 'A New Kind of Rays' The Pre-history and Discovery of X-rays C.N. Brown

London, including a discharge tube which is cracked at the end (Fig. 3) because he used a magnet to focus the cathode rays in order to obtain a better beam of X-rays, and in doing so he overheated the tube. The Science Mu- seum also has copies of some of Swinton's earliest X-ray photographs, including one image taken through an aluminium screen and another through a mahogany dark slide, both made on 8 January 1896, the day after he had seen a press report of Rontgen's work. Flushed with success, he wrote to the Etcnin,R, Standard, which published his letter two days later. There is also an X-ray image of his own hand, which he made on 13 January and showed to the Camera Club three days later. A better X-ray picture of his hand, taken on 18 January, was published in Nature on 23 January, in the article immediately following the translation of R6ntgen's paper.

Fig.1 Wilhelm Conrad Rimt~,en (1845- The ready availabilityof the apparatus to 1923). make X-rays underlines the point that the Fig.2 Rimtgen'~ X n~y phato~,,r,Tph q! /n., discovery had an extensive pre-history to wife~ hand, taken in December 189.5. In the first few days of 1896, eminent which many eminent and well known natural philosophers made contributions. scientists in various countries received R6ntgen had been investigating electrical copies of a strange paper from Wilhelm decently equipped physics laboratory. It discharges in gases at very low pressures, Conrad Rontgen (Fig. 1), the worthy, but needed a Ri~hmkorff or induction coil, a subject which had interested natural previously not very well known, Professor plus batteries and other accessories, an philosophers for two centuries.' Jean of Physics at the University of W0rzburg. ~ electrical discharge tube of the type Picard, in 1675, had noticed flashes of The paper announced the discovery of 'a known in Britain (perhaps somewhat light in the vacuum of a barometer when new kind of rays' which R6ntgen called X- chauvinistically) as a Crookes tube, and the mercury was shaken, but he did not rays, though in much of Europe they are a screen coated with a fluorescent know these were electrical in nature. now often called R6ntgen rays. They had substance such as barium platino- Francis Hauksbee, in 1705 and the years the amazing property of being able to pass cyanide. When such a tube is connected following, devisecl an apparatus for through opaque bodies and reveal what to a source of very high voltage, cathi~le investigating this 'mercurial phos- was inside, or behind, them, as a dark rays are given off from the cathode. They phorus', and also produced luminescence shadow on a glowing fluorescent screen, travel through the highly evacuated tube with an electrical machine. Abb~ Nollet or on a photographic plate. Among the until they are stopped by the glass at the looked at di.~'harges in an evacuated glass images which R6ntgen distributed was an tar end, making it glow green and at the bulb later called an 'electric egg' in about image of a human hand (Fig. 2), showing same time producing X-rays. When the 1748. Around 1750, William Watson used the outline of the bones within. It was his X-rays hit the screen, it fluoresces. an evacuated glass tube. Faraday was still wife's hand and in those days it was a Rontgen's induction coil and some of using similar apparatus, a crudely evac- most disturbing image. his discharge tubes are preserved at the Deutsches Museum in Munich. uated vessel and a friction electrostatic machine, as late as 18.~. Lord Kelvin was one of the recipients of the paper, and at first he was sceptical In Britain, A.A. Campbell Swinttm was To make progress in understanding about it, and he would not have been the one of the first to investigate the new electrical discharges, better vacuum only one, but he was sufficiently gracious rays. ~ Swinton was a man of wide pumps and better sources of electric to send R6ntgen a congratulatory letter interests, he is well known in the pre- power were needed. Heinrich Geissler later in January. ~ it was not a mistake or a history of television as the man who overcame the first problem dunng the hoax, as the many scientists who repeated pri~n~ an all-electronic system, about eighteen-fifties, when he devised a R6ntgen's experiments soon proved for thirty years before it was put into vacuum pump which used mercury themselves. Kelvin was unable to do this practice. He had an induction coil and instead of mechanical pistons. Gei~sler because he was confined to bed with a discharge tubes in his laboratory. He is described as a glass blower at the bad leg. The only other person in Britain might not have had a fluorescent screen University. of l~nn, but he was a skilful known to have received a copy of the because it was not common equipment, and inventive craftsman who eventually paper was Arthur Schuster, Profes~r of though not difficult to get hold of, but he received an honorary doctorate for his Physics at Manchester. was an expert photographer and he work. He put his skiils to profitable use recorded his X-ray images phot(~graphi- by making intricate glass tubes, evacu- It was not difficult to replicate ROntgen's cally. Some of Swinton's apparatus is ated and then carefully filled with work. The apparatus was in every preserved at the Science Museum in various gases and liquids, so that they

Bulletin ot [he Scientific Instrument Society No. 46 (1995) 23 t ./

F-t Fig.4 Sydney Rowland takm~ an X-ray Ill ." IlmmI~ " ~ I photograph early in 1896.

Fig.3 D~scharg,e tub" similar to one used ht Rimtc,en when he d~scaz~'red X-rays. This is the tube which behmc,ed to Campbell Crookes is one of the men who might Su'mton, and u~s damaged when he u~d a mac,net to focus cathode have di~overed X-rays, but did not. He is rays on to the glass known to have returned photographic plates to the manufacturer because they were fogged. He did not think to look for glowed with different colours when an detected by the glow they produced electrical di~harge was passed through the cause in his own work. It was behind the cathode. They are real, but probably X-rays, but it might just have them. They became known as Geissler they have no great significance. tubes, and" for a century or more they been radioactivity, which was not dis- were u~,~cl in delightful ~:iectrical demon- covered until the following year, 1896. A It was one of Pliicker's students, Johann strations. Many people remember them lot of surviving apparatus from Crookes's Hittorf, who first demonstrated one of the from their schooldavs. It was the Geissler laboratory shows low level radioactive key properties of cath(~e rays, that they pump that made them possible. contamination. Crookes was not even in a travel in straight lines, in 1869. In Britain position to investigate X-rays when they Hittorf's work was not well known, and were announced, because he was on a The other problem, the provision of a the standard apparatus for demonstrating visit to South Africa, but experiments better power source, was solved by the this property was a tube designed by were done in his laboratory in January Ruhmkorff induction coil. A lot has'been William Cr~kes and known as a Maltese 1896. X-ray photographs were taken of a written about the origins of the induction Cross tube, becau~ it uses a piece of metal lattice, and the lattice, the images coil. ~ it was inxented by the priest- aluminium in the shape of a Maltese cross and the tube used in the experiments are ~ientist Nicholas Callan, at Mavnooth, to cast a dark shadow in the fluorescent all preserved at the Science Museum. in Ireland, and various other scientists glow pr(v3uced by the cath(de rays. descnbecl forms of it, but it was the Parisian instrument maker Heinrich Crookes, like many in Bntain, thought William Crtx*kes is an important figure in Ruhmkorff who perfected it and made that cathode rays were negatively the history of cathode rays. He was it into a reliable research tool, and a charged particles. Others differed, nota- commercially successful product for his primarily a physical chemist'and spectro- bly Heinrich Hertz, who was later to work.~hop. scopist, and it is possible to trace links demonstrate electromagnetic radiation. from some of his chemical work (measur- Hertz had noticed that cath(~le rays can ing the atomic weight of the element penetrate very thin metal sheets. He t,Vith the new hxds, new di~'overies were thallium) to the invention of the Cr(x~kes made. Julius PliJcker, the Professor of thought particles could not possibly do radiometer in the eighteen-sixties and to this, so cathode rays had to be waves. Physic,, at I~nn, used tubes made by his extremely detailed investigation of Gei~,,ler to investigate the sl~.ctra of the Hertz's pupil, Philipp Lenard, went cath~le rays reported in lectures to the further, and constructed a new kind of ga~ di~harges, but he al~ noticed that as Royal Institution and the British Associa- the vacuum in the tubes improved, the tube with a thin aluminium window. He tion in 1879, and to weave in his interest in showed that cath¢~ie rays could pene- glow discharge with which he was spiritualism along the way. ~ The Crt~)kes familiar was replaced by something trate the window, and travel about two radiometer, an evacuated bulb containing centimetres in air, prociucing ioni~tion. emanating from the cathode, which a ,set of vanes which rotate in sunlight, has made the end of the tube glow green. He The argument over the nature of cath(de no practical application but is still made rays was taken up by J.J. Thomson, who, had di~-overed cathl~ie rays, though he and .sold, mostb,, as an executive toy. did not coin that phrase. It is due to Eugen in 1894, showed that cathode rays Crookes gave credit to his assistant travelk~ more slowly than light, and Goldstein, in l~,rlin in 1876. (,;oldstein also Charles Henr~, Gimingham, who made ms eshgated di,,~'harge phenomena, and then by Jean Perrin in 1895, when he the glass tubes and manipulated the deflected cathcde rays into a cylindrical in I~ he notict~ that there was another improved vacuum pump which Cr(~kes t,v[~, of rav, canal ravs or p~itive rays, electr¢~le connected to an electrometer, had devised. In an early example of and showed conclusively that they were which went in the-opposite direction, technological spin-off, Girningham later from the anl,3e of the tube towards the negatively charged. The argument was worked for Joseph Wilson Swan, helping finally resolved in 1897, when J.J. cath~.te, and if the cathl~e were perfo- to pr(duce the first viable incandescent rated they went through it and could be Thom.,~n measured the charge-to-mass electric lamps in this country. 7 ratio of cath(~e rays. Since they had a

24 Bulletin of the -ScientificInstrument Society No. 46 (1995) Fig.6 The X-ray tub,' bu MUller winch won a .~,,ld m,'da/:rom the R#ntgen Socie~. in 19011

to protect it by patents or in any other way. It is curious that in Germany commerce and industry was much better served by its universities than in Britain, but German professors seem to have been more unworldly. He was awarded the first Nobel Prize for Physics, in 1901, but declined to give a Nobel lecture.

The potential applications of X-rays were Fig.5 The X-ray apparatus built by Dr John Reynolds and his son realised very quickly by the more Russell Reynolds in 1896, as now presert~l at the Science Museum, imaginative of those who heard about London. the discovery. Within weeks some doctors were using them to help decide the best treatment for broken bones and gunshot wounds. There is a well-known picture in mass they could not be electromagnetic rays obsessively, at times eating and the Briti~ Medical Journal early in 1896 of waves, akin to light. Other scientists sleeping in the laboratory. On 28 Sydney Rowland, a doctor who wrote elsewhere in Europe also measured the December he handed over a manuscript several papers about the use of X-rays, charge-to-mass ratio at about the same for publication in the Proceedings of the making an X-ray of someone's foot (Fig. time, but, at least in Britain, Thomson's Wiirzburg Physico-Medical Society. The 4). 'o By no means all doctors were work has taken precedence. It has come presumption is that it was added to an immediately convinced of the utility of to be regarded as the di~overy of the issue of the Proceedings that was already X-rays, and it took time for the use of X- electron, and will be a cause for in the press, certainlyit was printed very rays to become established in medicine, celebration at the centenary in 1897. quickly. Probably even before the journal but they are now indispensable. was issued he posted preprints to eminent physicists, along with some X- The most detailed, but not necessarily The oldest surviving X-ray machine in ray photographs (not always the same totally reliable, account of what R6ntgen Britain, if not in the world apart from ones). That paper was reprinted as a was doing when he discovered X-rays is R6ntgen's apparatus, was assembled in separate item a further five times. He based on the one major interview he gave 1896 by Dr John Reynolds and his fifteen- published a second paper later in 1896 to a journalist.' He was following up the year-old son Russell Reynolds, who later and a third the following year, and so work of Hertz and Lenard, using paper presented it to the Science Museum thorough was his work that neither he coated with barium platino-cyanide to (Fig. 5)." They made as much as nor anyone else added much of scientific detect cathode rays close to the tube. possible including the induc- significance to it for a number of years? then~elves, Rontgen had covered the tube with card, tion coil, but they had to buy the X-ray and was working in a darkened enclo- tube. [.x~okingat this equipment, one can sure. Partly because of this he noticed R6ntgen's discovery was reported in the see how the prime electrical di~overies that the paper glowed even when it was Wiener Presse in Vienna on 5 January, the of the nineteenth century, come together two metres away from the tube, far out of Frankfurter Zeitung on 6 January and the in early X-ray sets. The power source is a range of cathode rays in air.Rays of some London Standard on 7 January. English primary battery, developed from Volta's other sort were emanating from the end translations of the paper were published pile of 1800. The induction coil relies on of the tube, under the influence of the in Nature on 23 January and in the electromagnetism, di~overed by (-)ersted cathode ray bombardment, and had Electrician the following day. Rontgen in 1820, and also on electromagnetic penetrated the card around the tube. demonstrated X-rays to the Kaiser on 13 induction, described bv Faraday in The report of the interview claims that January, and lectured about them in 1831. The X-ray tube is the culmination the date was 8 November 1895, though Wiirzburg on 23 January. Thereafter he of two centuries of work on electrical later R6ntgen said he did not know the refused invitations to speak about X-rays. discharges in gases. Russell Reynolds exact date on which he had first noticed He made no attempt to take commercial went on to become an eminent medical X-rays. In following weeks he studied X- advantage of his discovery, nor did he try radiologist and lived until about 1965. He

Bulletin of the Scientific lnstrmnent Society No. 46 (1995) 25 was fortunate, because many of the X-ray part of the story of X-rays. There were 4. For a di~cus~on o~ the precursors to X- pioneers died of radiation poisoning. radical developments to come, notably rays, wRh full references, see G. Sorton, 'The Reynolds noticed early on that exposure the gradual introduction of the thermi~ dix~wery of X-Rays', Isis, 36 (1936), pp. 349- to X-rays made his hand red and sore, nic X-ray tube from 1913 onwards, and 364. All the names mentioned below also and took care to avoid unnecessary the replacement of the induction coil by feature in C.C. Gillespie (ecl.), Dict/o~ry exposure, but by modem standards he Scientific Ba~rwpPnt (New York: Charles Scrib- power supplies using high-voltage trans- net's Sons, 16 vols., 1cf70-1980). must have received a very heavy dose formers. There are also social aspects, during his lifetime. hinted at in cartoons in magazines such 5. See G. Shiers, 'The Induction Coil', as Punch and Life." Inevitably there were Sc/entificAmerican, 224 (1971),pp. 80-87. In 1896 and the years that followed, there some who tried to belittle Rontgen's 6. See E.E. Foumier D'Alhe, The L/fe of Sir was much experimentation aimed at achievement or to ascribe the discovery William Cnk~kes O.M., F.R.S. (London: T. Fisher improving X- ray apparatus, particularly to others, but they had little support. Unwin Ltd., 1923). For accounts of Crookes's tubes. In the Cwokes tubes used at first, Rontgen can be regarded as a mildly lectures see Nature, 20 (1879), pp. 228-231,250- 254, 419423 and 436-440. X-rays were pnxluced when the cath(~e eccentric scientist,working in secret, who rays hit the glass. It was a better idea to made a totally unexpected discovery 7. M.E.S.k K.R.S.(ME. Swan & K.R. Swan), use a concave cathode to locus the which brought him fame overnight with Sir ]oseph Wil.qon Su~n, F.R.S.(London: Ernest cathode rays on to a small area of a (almost) no arguments about priority,hut Bann Ltd., 192% pp. 66 and 73. metal target within in the tube, and the who remained modestly unaffected by 8. The interview by HJW. Dam is the basis best target material at the time was his new status. There are elements of of his article 'The New Marvel in Photo~a- platinum because of its high melting caricature in describing Rimtgen and his phy', in McClure'sMagazine, 6 (1896),Pp. 40~ point and because it is more efficient at work in this way, which conforms closely 415. pn~ucing X-rays. Herbert Jackson, tater to the idealised stereotype of the process 9. The X-ray papers are W.C. R6ntgen, Sir Herbert Jackson, Daniell Professor of of scientific discovery as perceived by the "Ueber eine neue Art von Strahlen (Vor- Chemistry at King's College London, is man in the street, but there is also a core ~ufige Mittheilung)', Sitzungs-Berichten dee credited with introducing this type of of truth in it. R6ntgen's discovery of X- Physikalisch-medizinischen Gesellschaft zu tube in Britain, in March 1986, and for a rays is highly unusual among scientific W~/rzbu~, 1895, pp. 132-141; 'Ueher eine neue while the Jackson focus tube was the discoveries, most of which are sub~ct to Art von Strahlen. II. Mittheilung',/b/d.,1896, standard." it seems to be a case of Pp. 11-19; and 'Weitere Beobachtungen giber as much contention and dispute as events die Eigenschaflen der X-Strahlen', Sitzunxs- simultaneous invention, because in any other walk of life. berichte der K#nixlich Preusslschen Akademie der Rontgen mentioned in his second paper, Wissenschaflen zu Berlin, 1897, pp. 576-592. published in March 1896, just such a tube As well as being enormously important English translations have been printed in a with a concave cathode and a platinum not only for medicine but also for number of publications, in particular in O. anode angled at 45°. industrial testing, the discovery of X- Glasser, op. cir. (Note 1). rays was one of three major discoveries 10. SD. Rowland, 'Report on the Application The Rontgen Society, which had been set in physics in the last decade of the of the New Photography to Medicine and up to promote the use of X-rays and to nineteenth century. The others were the Surgery',British Medicallournal, 1896, p.l. bring together those interested in the discoveries of radioactivity, in 1896, and II. ScienceMuseum inventory No. 1938-645. sub~,ct," organised a competition in 1901 the electron, in 1897. Between them they The constructionof the coil is described in J. to find the best X-ray tube. Twenty-eight set the scene for the atomic and nuclear Reynolds & RJ. Reynolds, The EnglishMechan- tubes were tested and the gold medal physics of the twentieth century, a vast ic and World of Science,46 (1898) pp. 598-599. was awarded to one made by C.H.E new area of study unimaginable only a See also R.J. Reynolds, 'The Early History of Moiler, of Hamburg. In construction it few years earlier. Radiology in Britain', Clinical Radiolo~/, 12 was typical of the standard diagnostic X- (1961), pp. 136-142. For an obituary of Russell Reynolds see British Iournal of i~liok~V, 38 ray tube of the period, with a concave Notes and References (1965), p. 71. cathode, an inclined platinum target, and a separate anode (a third electrode I. The only comprehensive study of 12. See H. Jackmm, "Note on the Use of connected to the target), becau~ tubes Rontgen in English is O. Glasser, Wilhelm Certain Phosphorescent Substances in Render- with this construction were found to Conrad Rimtgen and the Early Histo~. of the ing X-rays Visible, Pnx'eedin~s of the Chemical S0c/ety, 12 (1896) pp. 57-60. The description of work better. This prize-winning tube R,wntgen Ra~ (London: John" Bale, Sons and Danielsson, 1933, and Illinois: Charles C. what was later called the focus tube is on (Fig. 6), and the test plates taken with page 58, in No. 62, issued on 17 March 1896. it, survive in a collection of X-ray tubes Thomas, Springfield, 1934, reprinted San FrancLsco: Norman Publishing, 1993). B. Dib- belonging to the British Institute of 13. See J.S. & H.G. Thompson, Sylz,anus ner, The New Rays of Pn!fes~r Ri~ntgen (Nor- Phillips Thomps~m. His Life and Letters (Lon- Radiolog,," and on loan to the Science walk, Conneticut: Bumdy Library, 1963), is a don: T. Fisher Unwin Ltd., 1920), pp. 19.~-199. Mu.,,eum it is likely that many of the X- shorter study based mainly on sectmdary Thompson was the first President of the ray tubes sold in Britain were made in sources. H.S. Klickstein, "Wilhelm Conrad Rontgen Society. In 1928 the R6ntgen Society Germans; even when they carried the Rimteen. On A New Kind of Rays. A Biographi- was incorporated into the British Institute of name of a respected British instrument cal Study ISt. Louis? USA:" Mallinckrodt Radiology, now at 36 Portland Place, London, maker, but Muller actually made tubes at Classics of Radiology, Vol. 1, 1966) is a short WIN 4AT. his British works. The business was taken but highly detailed study with full references and a bibliography of Rontgen's papers, but it 14. 'Collection of Cuthbert Andrews 1910- oser by the Receiver of Enemy Property Ls difficult to find. It is not listed in either the 1980', Science Museum Library, [.xmdon, in 1~14, but was bought by" a former Library of Congress Catalogue or the British (Archives Collection). employee, Cuthbert Andrews, who con- Libra~ Catalogue. There is a copy at the 15. In many issues dunng 1896, frt~n about tinued 1o make X-ray tubes for many Science Museum, Lond(m. March imwards. ~ears." That tirm stiJl exists as Every- 2. See S.P. Thompson, The Life of h~rd Kdz,in All photographs are by courtesy of the ihing X-Ra.v, at Bushev in Hertfordshire, (Lxmdon: Macmillan, 1910), wd. 2, p. 954. but as a supplier o'f acces.,~mes and l~ard of Trustees of the Science Museum, disi~,dbles, not as a manufacturer. 3. See T.H. Bridgewater, A.A. Campbell Lond(m. Su,inton (l~mdon: Royal Television &)ciety, Author's address: 1982) for ink~rmation" about Swinton's life l'he di~'overv of X-rays, and events of Science Mu~um and work, especially pp. 11-13 for his X-ray South Kensington the earl.v )'ears of their u~, are only a activities. London SW7 2DD

2~, Bulletin of the Scientilic Instrument Saciety No. 46 (1~) Facsimile File Popov Versus Marconi: Repeating their Pioneering Experiments of 1895 Ralph Barrett

consisting of a metal plate connected to one side of the coherer, and the other side attached to a plate buried in the ground After tests in the attic at Villa Griffone it was taken to the garden. His transmitter had a similar 'aerial and earth' connected to a Right-type spark gap with the end spheres removed, and energized by a 10-inch induction coil. Marconi super- vi.~,d a remake of this transmitter. ~me year later a replica (Fig. l) was made for the Marconi Company at Chelmsford.'

The Facsimile~

k_ Our transmitter and receiver are shown Fig.1 Rq#ica of Marco,is in Figs 2 and 3 respectively. Cooking foil ora?,inal transmitter at Villa over cardboard 53 cm square provided the plates. The transmitter spark gap Gri~,ne. consisted of two metal spher~ ~ to l cm to pr(~uce continuous sparks. A Fig.3 Iac~,mtih' qt the ~,'dla 10-inch induction coil [:x~wered by a Fig.2 facsimth" ~?f the Vdla Gr~me receir~r. 12 volt car battery, and a Morse key Griffone transmitter. The completed the transmitter. ground plate is shown under the table, and is buried in Marconi was satisfied with a working the original apparatus. range of 3 kin. Our model worked well at about l0 m which was the maximum distance available in the lecture theatre of This paper is based tm a demonstration ment using a coherer 2 as detector. the Institution of Electrical Engineers. lecture 'Popov Versus Marconi' which Popov's apparatus was designed for was given at the Institution of Electrical recording atmospherics, and for use as a Engineers on 2 November 1994 to storm detector. Marconi's apparatus The circuits of our facsimiles followed commemorate the 1895 epoch-making received man-made signals from a those of the original designs as depicted in experiments of these two pioneers of transmitter after the style of Righi Fig. 4. The Marconi receiver on the right (b) radio. The aim was to shed some light (similar to the Teyler's Museum appara- uses a Post Office-type relay and tape on the often discussed problem who of tus to be described by Bob Caron in the printer (Mor~-writer), resistors con- these two, Popov or Marconi, could claim next Bulletin). It did not take long for nected to the contacts to avoid spurious the priority of this invention. The both Russia and Italy to put forward sparks, and RF chokes to i~late the relav intention was to verify the operation their national as the inventor of radio. and battery. Polx~v's circuit (a) on the left and the limitations of their apparatus shows thel~ell and bell hammer to tap the and early experiments by means of coherer into its pristine state of sensitivity, Marconi did much work on the coherer. and the single batteo'. working replicas. He discovered that metal particles consisting of %% nickel and 4% silver Marconi fi~und a separate coherer battery Introduction gave very sensitive operation. Inside a was important, the voltage to be kept low glass tube he made a wedge-shaped gap as a large coherer current would cause After studying at the University of St between two silver electrodes, measuring self-coherence. In Popov's receiver with Petersburg, Alexander Stepanovich l mm at the ch~sest part. With the gap the single battery, a delay in decohering Popov (1859-1905) joined the staff of the about half filled with these metal was apparent. :['his would reduce the Navy Torpedo Sch(x)l at Kronstadt, and particles, rotation of the tube would speed of Mor.,,, operation, in order to soon became Head of the Physics alter the space occupied by the particles. keep the coherer current low a sen.,,itive Department. The library had foreign relay is necessary. Marconi found a P~vst journals, which stimulated his interest Our coherer work soon centred on the Office relay coul;J be made to operate at in the work of Heinrich Hertz and the British 10p coin, which contains a large lmA, while Popov u~'d a Siemens- demonstrations of Oliver [zxtge.' amount of nickel, and using a file with a Halske relay. fine cut, pr(~uced very satisfactory Guiglielmo Marconi (1874-1937) was a particles. These were placed in a glass It was discovered that for our reconstruc- younger contemporary of Popov, a non- tube of 4 mm inside diameter, between tions a relay with a simple horitontal academic who called himself the 'ardent brass plugs making a wedge-shaped armature was the best, and after repla- amateur of electricity'. He pursued space. Particles from a Victorian shilling cing the spring by a small balancing experiments in his father's mansion, were also tried unsuccesfullv as the large weight, the operating current could Ix, Villa Grifone, near Bologna, and al~ amount of sih'er produced continuous reduced to 4mA. The batteries for the read of Hertz and Ltxige in journals conduction2 receivers were made up of 5 volt nicad sent from England. units of h~ur cells. Our facsimile Popov Marconi discovered very quickly the receiver with its 'exploring r,~i aerial' In 1895 both constructed radio equip- importance of using an elevated aerial, billowed his circuit faithfully, including

Bulletin of the Scientific Instrument Society No. 46 (1995) 27 1 Fig.4 Circuit diagrams of the Popov I '.~1 "~ recenw fat and Marconi recei1~r fb~. - "~ its metal box container, as described by ~I1 ...... Victor Gabel in 1926 to the Wireless World i~ ~. (Fig. 5). Sometime later we managed to " obtain a picture of the original instru- . ~ Fig.6 Popov~ original receiver with case ment minus its case (Fig. 6), and remo~ed. descnbed as the 'world's first radio', it is preserved in the Mu~um of the Torpedo Sch(ad at Kronstadt. Popov demonstrated his receiver on 7 May 1895 to the Phvsico-Chemical fxx:ietv in Fig.7 St Petersburg. he u:sed it in coniunciion Hert:'s ,,rt,ginal tnmsmltting dlpoh, operating at 50 MHz. with a Hertz 'vibrator' (oscillator) of 30 cm The original Hertz dipole (Fig. 7) Fig.5 Facsimile l~ l'(,I,,)~"s re(el~,¢r, a,lth with 30 cm spheres can be seen, with other Hertz relics, in the Deutsches coherer CtopL relay Cbelowl, and battery. Museum in Munich. Its length is Cunderneath). 3 metres and its frequency 50 MHz. unearthed by modern historical re- For the sake of portability our dipole search. We know that Popov demon- (Fig. 8) was V4 scale with a frequency of strated his apparatus again to the 200 MHz. The large spheres at the ends Physico-Mechanical Socie~ on 24 March (in our arrangement placed vertically) 1896, but no actual records survive. Later, were balls of string wound to the correct some of those present remembered that diameter of 30 cm, and covered with the words 'Heinrich Hertz' were received ct,)king foil. The dipole is activated by a from a Hertzian dipole transmitter. 'boxed' motor car spark coil with However, this must have been quite a hammer break trembler, a Morse key, brief demonstration as it was one of nine i ...... Ji ! and 7.5 volts produced by six nicad cells. items on the Society's agenda for that day. If we admit the priority claim made After his demonstration Popov wrote a on Popov's behalf on the basis of :)'~: [, 1 7 • ~.-,: 7.~ paper entitled 'Apparatus for the Detec- historical research (and not published tion and Recording of Electrical Oscilla- primary source material), we must also tions'. He ends with "! may express the take note of Marconi's achievements at hope that my apparatus may be used for Villa Grifone in late 1894 and early 1895. the transmission of signals over a distance with the help of rapid oscilla- There is no record in print by Popov tions as soon as a source of such before Marconi's patent of 2 June 1896. (~scillations with sufficient energy, will There is only indirect evidence that be di~overed". However, his idea was Popov demonstrated transmission of misconceived and was ba.,~-~l on his use intelligence by means of radio waves on Fig.8 Facsimile Hertz's dipole operating at of this device (connected to a 'lightning 24 March 1896; but there certainly exists 200 MHz. conductor' aeriaP) for detecting the comparable evidence of Marconi's I~werful di~harges generated by elec- achievements at an earlier date at Villa tric storms. Marconi realized that what Grifone. I believe that according to these 3. On the action of the cl~e~r and replica- tions, see Pat Leggatt, 'Coherers in Action', was needed was not a more powerful criteria Marconi can be named the transmitter but a more sensitive receiver, Bulletin of the British Vintage Wireless Society, iS 'inventor of radio communication'. (19~0), pp. 16-18 hence his improvement of the coherer. Notes and References 4. P.R Jensen, In Marconi's Fa~tsteps. EarIv Our model l'opov receiver was also Radio (Kenthurst, NSW: Kangaroo Press, 1994), h~-ted bv connecting it to a long wire pp. ll-16. 1. Much has been wntten aix)ut Marconi, aerial ~uspended at .~me height. A but flw a brief surx'ev of Popov, see G.R.M. measure of .~ucct~,s was achieved as the Garratt, The Early Hisio~ ,~ Radiofrom Faraday 5. A similar aerial was used by Van der Ven (~'ca~ional tinkling from a distant storm to Marcani (London: lEE/Science Mu~um, at Teyler's Mu~um in 1897, see Fig. 6 of B(~ ~as picked up by this means. Iq~4), pp. 71-74. Camn's paper in the next Bulletin. 2. For a detailed sur~'ev on coherers, see V.J. The qut-,tion of priority has to be basecl Author ~ address: Phillips, Early Radio Wai,e Detectors (lx~ndon: 82 Lilliput Az¢nue either on printed publications of the Peter Peregrinus/Science Mu~um, 1980), contenders or on archival evidence Northolt pp. 18-64. Middlesex UB5 5PZ

28 Bulletin of the Scientific Instrument Society No. 46 (199~) Market Place in Germany

Karin Burchard

Fraunhofer refractor was set up in Puikowa, the Munich one was the most powerful telescope in existence. In 1882 Hugo yon Seeliger became the first director, where he remained for 42 years. Seeliger was one of the most famous German astronomers of his time. Due to his research the Munich observatory attained fame. in 1891 a meridian circle by Repsold was posi- tioned in a special room - this will later be described in more detail. During the twenties the city expanded close to the Observatory; street lights and tramways severely hampered astronomical observations, in 1944 the buildings were damaged by air raids, but most instruments and the library remained intact. After WW I[ research shifted to astro- physics, relevant data being collected in observatories overseas.

On my first visit to the Obeervatory the directors dispelled my concerns about this transaction indicating that their prime objective had to be scientific research. Once the instruments were placed in a museum these would be more easily accessible to the public Fig.l Old photograph of an astnmomer usm¢, the RtT,_~,l,t tm'ridlan compared to their relative seclusion in circle of the Munich Observato~ at the turn of the centu~. the Observatory.

When I finally saw the entire inventory of the Observatory's historic instruments One early morning last winter I was wide awake and offered to come and there was some di~pl~intment at first. sipping coffee looking at the snow look at the collection within the hour in settling in the dark when the phone order to select items for sale. As it turned Ordinary sextants, reflecting circles, theo- dolites, artificial horizons, and ~mall rang. A chap was talking about a out, ! had to wait two weeks, time hand-held telescopes which could be telescope under construction in Austin, enough to do some homework. acquired from any London dealer or Texas, consisting of 9I hexagonal seg- auction. However, there was one magni- ments making a mirror II metres in The Royal Observatory of Munich was ficent ob~ct that immediateh' attracted diameter. He continued by indicating founded in 1816 in the village of my attention, it was the huge meridian that his institution was in urgent need Bogenhausen, by now one of the inner circle made by the Hamburg firm of of extra funds to meet the commitment in suburbs close to the park area of the Rep.~ld, positi'oned in the former mer- financing their share of the project. A 'English Garden'. The site on a small hill idian room exactly in a North-South truly 'astronomical' sum was mentioned. amidst the meadows was most likely direction, l'he telescope, with a 16 cm Whilst I was contemplating how to tell chosen by Joseph yon Fraunhofer, and by objective, can only be turned in a the caller to go on a long walk on a short the first director Johann yon Soldner and horizontal plane. The large drums on pier, the person remarked in passing that Georg yon Reichenbach. In 1819 a either side of the telescope tube which he represented the Observatory of meridian circle of Reichenbach and Ertel hold the axis and pivots are equipped Munich-B~enhausen. His directors had was installed at the Observatory. This with counterweights so as to reduce the decided to sell as many of their historic delicate instrument may be admired in wear and tear of the bearings. The pas~ge instruments as would be necessary to the lobby of the main building of the new of any observed star and its respective raise the funds. In utter disbelief I asked Institute of Astronomy. in 1835 the angle of inclination versus the zenith i.,, whether the projected transaction was Scotsman, Johann yon Laumont, suc- read by micrometer micr~-opes, lh-- supl~rted by the Bavarian Ministry of ceeded to the post of director, in this tween 1908 and 1914 the position and Education as they have the reputation of year a 10~,'z inch refractor by Fraunhofer parallaxes of almost 9000 stars were being as conservative and inflexible as and Mertz was delivered which now determined with this instrument. the Department of Inquisition of the stands idle in its historic building with its Vatican. He replied that the senior dome-shaped roof, Unfi~rtunately many A turn of the century photograph exists officials of the university had agreed alterations were made to this telescope. depicting an unknown astronomer in his stipulating that they favoured a transfer The tube today is painted white, reclining chair observing the sky (Fig. I ). to a museum in Germany. The institution electrical wires dangle from the ocular, When rummaging thn~ugh the attic and needed some assistance in determining and it is hardly recognizable as one of the annex building of the Fraunhofer the value of the objects and advice on Fraunhofer's masterpieces. For the few telescope, the entire inventom as shown how to place them. By that time ! was years till 1839, when the 14 inch on the photograph was di~overecl. The

Bulletin of the Scientific Instrument Soc~ No. 46 (1995) 29 c""

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Fig2 I.,,' t<:,':,, ;,,,',,.:,,. .~-t,(,.,,m~,,ii ,,,~k~ at /he .%hm.h Fig.3 Close up ot (,tic I!t ttlc RIcth'r cfi~ck>. Observatori¢ to bc transti'rred to the Berlin Mu.q.um flir Verkehr und Technik cMVTL

original chair, steps on rollers, and other their production line of drawing sets, transcribe this to Great Britain this would items were all there, only the curtains compasses and the like. be comparable to a sale of the Royal and, of cour_,~,, the a.~tronomer were Scottish Ob~rvatory to the Science mi_,,sing. ]-hi.~ presented the unique Museum -can you imagine? opportunity for a mu.~,um to reas.,,emble To cut a long story short, a package deal the original ~etting of the meridian circle. was negotiated. Much to evervb(~v's During the sub~'quent .,,ales negotiations, surpri~, the Pa,rlin Mu~um fur ~/erkehr In general, the scientific instrument thi~ pro~ed a crucial aspect in .~'curing und Technik (MVT) was granted extra fraternity in Germany either does not the tran>action funds and took delivery in the autumn of exist or keeps a very low profile. There that year. The MVT is currently in its are no speciali.,,~,d auctions with the devel(~pment stages, with only a few exception of the Action Team in Cologne (~n in,q~,hng that more in~,truments sections completed. The building for the who predominanth,, .sell old toasters and ,hot.ld be included to raise the Marine Department and Aviation is very few ~ientific instruments. There are nete,,arx tund~,. I ~a~ led to the clock under construction. It was originally few fairs like the Technica Antiqua roon~ in the ba,.ement. There, eight planned to occupy the huge former catering to the clock, watch and swatch a',tronomlcal preci,,ion pendulum Anhalter station, dt~troved in WW II, colh~ctor. None rivals Peter Delehar's Fair clock, I~ere ticking including two which adjoined the ~,rlin wall. Part of in Ixmdon. (he can only speculate why tank ch~-k,, by S Riefler (Figs. 2 and the property belonged to the Reichsbahn there is no genuine and widespread "~ th,th art' titled with a banmleter, of the (;DR The political situation has interest in historic ~ientific instruments therm~mwter, h~grometer and an air changed dramatically, and ti~av the area in (.german),, apart from the mu~um pump lhe.,e tamou,, clocks repre~,ent is located in the "centre of the new professionals. Maybe this should be the tht' t'pltomt, ot '.~phi,,tication of me- German capital in a prime Fa~sition. The topic of a future ;Letter from Germany'. chanical ch~k,., with an accuracy of property is invaluable. When completed, In the meantime, i will be waiting for 0 ~,)l tL~ t)i)O?, .~'c(,nd~ For many vear~ the MV'[ will be one of the largest more early morning phone calls with It'- "q',ter cl~k no ~o ,~'r~ ed a~, thetime technical museums. The material pur- perspectivt,,s to shtn~t for the stars. reterem~, in the USA. I-hi,, one is now chased from the Munich (g',.~,rvatorv will hou,,ed m the .";mith~mian In,,titution in form the nucleus of a future astrono'mical Schloss~tras~ 6 !Aa,,hmgton lhe Rietler company dis- display'. Per~mallv, I remained ~eptical D-85354 Haind.flm¢, c, mhnued their pn~|uction of a~,tronom- whether this transfer from Bavaria to f reisin£ =cal ch~-k~ and t~,lav are renowned for 'Prussia' would eventually happen. To C.ermany

Bulletin of the ."kientific Instrument ~cieh,. No. 46 (1~5) Book Reviews

Opinions expressedby revieu~rrs are their own, and do not necessarily re)qect the views of the Editor or the Society

The Mapping of the Heavens astrolabe is always a pitfall for general balance (1861-70), a Nobili astatic galvan- Peter Whi(field authors. ometer with a glass dome (1871), and a British Library, London, 1995, 134 pp. Chladni plate (1861-70). Some instru- ISBN 0-7123-0402-9 Despite these qualifications, at the level ments are signed by G. Allemano only: £20 of a general survey, this is a valuable a De Winter electrostatic generator book with beautiful illustrations and it is (1870), an electric egg (1875), and a This is an illustrated survey of celestial reasonably priced. Anyone concerned Varley-type condenser (1882). The only charts from ancient times to the Hubble with early mathematical instruments identified English instrument is a nine- space telescope. The many illustrations - should regard cartography in general, teenth-century Dollond terrestrial tele- most of them in colour - are well chosen and perhaps celestial cartography in scope acquired in 1886. Another non- and beautifully reproduced. The author particular, as part of their domain of Italian instrument that caught my atten- takes it as axiomatic for his work that the interest, so there is much here to please tion is a Holtz machine by Lenoir and charts cannot be understood without and inform instrument enthusiasts. Foster of Vienna (1875). reference to the astronomy that produced them, so a good deal of history Jira Bennett Many instruments appear to be un- of astronomy is contained in the accom- signed, such as a very fine Musschen- panying text. broek pyrometer (1861-70). Several of these may have been made 'in-house' Inevitably in a book of such a large Strumentaria alia icoperta dell'antico by technicians of the lyceum, such as a scope, specialists in particular fields will Laboratorio dl Fisica del Licee Ariosto simple siren (1873) and a spark-gap find inaccuracies. If I assume that the (1860-1924) (1876). Incidentally, the dates in brackets specialism of readers of the Bulletin is Paola Bertolini Marzola, Enrico Bresciani, are based on the inventory. scientific instruments, it has to be said Rita Culatti Cavallini, Bruna Fergnani, that, while the general account will be Mara Graziani Bottoni, Isabella Stevani, No attempt has been made to compare valuable, the detail is not always precise. Maria Grazia Zerrillo Modestino individual instruments with those found In the account of the astrolabe, for Lions Club, Pcy,gio Renatico, Ferrara, 1995 in other Italian collections, or to produce example, there are some problems. 117 ~ any kind of historical analysis. On the There is no precise sense to the no price indicated other hand, the descriptions are clear and statement that the fete is a star map the material is yet another source of 'raw giving positions 'as if viewed from the This catalogue features one of those data' useful for future ir~strument histor- north celestial pole'; the point of typical physical cabinets put together by ians, in particular for those specialising in projection is the south celestial pole, the 'scuole superiori' between 1860-1915, natural philosophy or physics. One is but the resultant map is presented as and now being re-discovel~l by a very struck by how few non-italian (signed) seen from the northerly side. We are told active group of scientific instrument instruments are to be found in this that 'the lower plate was incised with a historians, such as Giorgio Dragoni of cabinet, and of their uniform good system of celestial co-ordinates, with the University of Bologna who was the quality. lines of latitude and azimuth'; the lines scientific consultant for this particular on the latitude plate are of altitude and pro~ect. The first manuscript inventory of Willem Hackmann azimuth, and these are not celestial,but the teaching collection of the Liceo local, co-ordinates. We are told that the Classico "L. Ariosto" dates from 1861. astrolabe 'was not restricted to a Indeed the 65 instruments featured in particular time of the year, since the this catalogue range from 1861 to the In Marconi's FootStel~ - Eady Patdio rotation of the fete over the horizon [sicl early 1880s, apart ~m two Jackson X- Peter R. ]ensen plate brought into view the stars of any ray tubes and a 'Maltese Cross' tube that Kangaroo Press, 3 Whitehall Road, given season'; this may be a confused date from 1924. Kenthurst, NSW 2156 Australia way of saying that for any date the PO Box 6125 Dural Deliz,ery Centre 2158, astrolabe will show the stars that move The first part sets the scene and places 1994, 176 pp above the horizon when the sun's this collection in the context of science IS BN 8-864 ! 7-607-4 ecliptic position traverses the portion of teaching in Italy. The second part is the $49.95 the latitude plate beneath the horizon actual catalogue. The format is a well- line, but the advantage of the astrolabe tried one: each page features a single Marctmi has been celebrated on medals, is that it "shows the position of every instrument with a photograph (many in coins and postage stamps around the body on its map every day, whether it is colour) and a description. These descrip- girlie. It would be nigh impossible to visible or not. We are told that the tions are to the point, give the instrument read all the books, papers and pamphlets astrolabe separates 'the objective map of maker (but not a transcription of the that have been wntten about him. His the entire northern heavens from the co- signature), the date (most often based on face is one of th~rse instantly rec(v,,niz- ordinate network which gave their [sic] the manuscript inventory), and main able. So why another b(x~k?"This book actual positions in space and time'; the dimensions. has two novel features: the auti~r's very co-ordinates indicate observed or appar- personal way of recounting Marc(mi's ent position for a particular latitude, but It is very obvious that this was a teaching history (l'art one) and his recreation of a the time (local) when that star is in that collection. There are four m(xtel pumps number of important early wireless position is given by the orientation of by Tecntnnasio ltaliano of Milan (1875), artefacts using m(~em techniques and the rete, specifically from the position of but they supplied a whole range of materials (Part two). the sun as represented by the appro- instruments such as a Meiloni thermo- priate date or zodiacal degree. Your pile (1879), a Breguet thermometer (1871) The b~x~k is concluded by seven exten- reviewer has to admit that he did not and a Fortin barometer (1884). Franchini sive Appendices repr~xiucing original see quite this many problems until he of Bologna supplied an electric bell material tm key epise~ies of early radio began to substantiate his general com- (1880). The only other Italian maker such as selected letters from Marconi to ment regarding detail and so to look represented is G. Allemano and Gastaldi Preece from November 1896 to Septem- more closely at the text. Perhaps the of Turin, including a fine hydrostatic ber 1898 (Appendix 1); the first and

Bulletin of the Scientific Instrument Society No. 46 (1995) 31 !

----4 Fig.l Contc,tporary artist ~ mtl,re~s,m of Fig.2 c)n,' ,,e the m.m/ p.t,/.itu pl,~t0~,'nl/,h, o! M,.~om I1.. ore' t~ take~z m 1'~11, amt Clud Marconi Wireless Officer ]ohn George sh~n.~. Marconi posm¢, with some early apparatus artisticalh/ arranced, includin¢ a ten-inch Phdhps ~ndin¢ his lasi wireless distress induction coil, Mor~ key, Morse writer, and the box containin¢ the coherer and'batteries, in mes~c, es frmn the RMS Titanic. in the front there is a linesman's indicator, a key. instrument of the tele~,raph engineer, but not of background the famous multiple tuner. wireless telegraphy. second technical reports of the Marconi home in which Marconi began his system bv the General Post Office, dated something of what Marconi must have experiments in late 1894, and then felt when he tried to bridge this gap for 15 OctoL~er 1896 and 29 October 1897 moves to the sites in London where the (Appendices 2 and 3); Marconi's famous the first time by means of wireless, it was "boy inventor' (he was only 21) sought in the nature of things that Marconi's "four sevens' patent of 1900 (Appendix 4); his fortune in 1896 by gaining support Captain Jackson's secret Admiraltv re- sites had to he fiat and away from natural from the English scientificestablishment and man-made obstacles. The author's port of experimental wireless telegraphy (Fig. 2). A kindly A.A. Campbell Swinton apparatus on HMS Defiance in 1897 photographs capture the remoteness of wrote a letterof introduction to William stations such as Clifden and Caernarvon (Appendix 5), Marconi's Report to the Preece, the engineer-in-chiefof the Post Marconi's Wireless Telegraph Co. dated (constructed in 1912). Littleof these once Office. Marconi was undoubtedly helped thriving stations remain. By treating December 1901 about his first trans- in his endeavour by his family connec- atlantic w/t experiment from Poldhu in Marconi in this way, the author has not tions. Preece loaned him the Post Office only given a realistic impression of Cornwall to St John's, Newfoundland. engineer, C.S. Kemp, who became one of An interesting aside is the correspon- Marconi's achievements, but also of the Marconi's earliest and most faithful surroundings in which the events took dence with a belligerent Anglo American employees. Telegraph Co. who tried to stop Mar- place. He has certainly managed to bring coni's experiments (Appendix 6); and Marconi to life. The author's pilgrimage has taken in all finally (Appendix 7) the press report of the important Marconi sites: the Malt the surviving wireless officer of the House near which his 1896 Salisbury Titanic, taken from the New York Times In the second part the author gives a Plain demonstration took place and of Friday, 19 April 1912. For the first time step-by-step account of the key instru- Hillcrest Bungalow where he established ever a drama at sea unfolded on wireless. ments which he has reproduced. There his base, the Bristol Channel between The senior wireless officer drowned are helpful photographs and drawings. Pearth and Brean Down for his first because he refused to leave his post. A The instruments include a ten-inch transmission across water in 1897, the induction coil, a coherer, the aerial jigger con,,~quence was the tightening up of Needles as seen from the former Needles wireless procedure at sea, and the ship's and multiple tuner, magnetic detector Hotel for his 1898 Isle of Wight experi- and its condenser box, a rotary spark wireless officer became in the eyes of the ments, Poldhu where Marconi con- general public a romantic figure (Fig. 1). transmitter and a crystal receiver. Some structed his famous station in 1901, his of the projects are more testing than Incidentally, radio communications has Clifden wireless station began in 1906 in developed so dramatically since the days others. Furthermore, the author's inten- Ireland, and so on. Although the story tion is not to make exact replicas but of the Titanic that soon ships will no told in these chapters is well known, longer be required to have on board a apparatus which behave according to the what makes it especially interesting and same principles but using modern radio officer as their apparatus will be evocative are the author's photographs operated automatically. materials. Whoever makes all these comparing the present day sites with devices can put together a pre-WWl original photographs. Many of these wireless telegraphy station - but one The author has managed to give a have been kindly supplied from the realistic impression of Marconi's achieve- word of caution, operating such a archive of GEC-Marconi in Chelmsford. station is totally illegal. ments by literally following in his foot- The author's bleak view across the Bristol steps. He starts in Pontecchio near Channel to Flatbohn and Steepholm with Bologna in Villa Grifone, the family Brean Down in the distance captures Willem Hackmann

32 Bulletin ,~ the .~'ientific Instrument Society No. 46 0995) Current and Future Events

Until 24 September 1995, Leiden College, Dublin, The Mind and the Hand, 10:30 to 17:00 hours because the Fourth exhibition of the history of Irish scientific National Vintage Communications Fair held For a few more weeks the exhibition of instrument making (see Editorial of on 14 May was so successful. Details globes and planetaria, The World in Your previous Bulletin). from Jonathan Hill (Sunrise Press), 3-4 Hands, at Museum Boerhaave, Lange St. Brook Street, Bampton, Devon EX16 9IX. Agnietenstraat 10, Postbus 11280, 2312 23-28 September 1995, Prague Tel: 01398 331532. WC Leiden, Holland. Excellent catalogue, price £15 is available. The Scientific Instrument Commission of 6 December 1995, London the International Union of the History Until 1 October 1995, Greenwich and Philosophy of Science will hold their The Society's 3rd Annual Invitation XIV Symposium in Prague, Czech Lecture will be given by Professor John The Wreck of the Titanic in the National Republic. It will be hosted by the Heiibron on Churches as Instruments of Maritime Museum, Greenwich. This Nitrodni Technick~ Muzeum. ! hope to Science, 17:30 for 18:00 hours at the Royal exhibition has been extended to I have a report in the next Bulletin. Institution, 20 Alhemarle Street, London October. Not very 'instrumental' but W1. quite spectacular. 16 October 1995, Oxford January 1996, Bradford Until lS October 1995, Edinburgh The Artist and the Moon: An Exhibition to Mark the 250th Anniversary of the Birth of 100 Years of Cinema is planned to open in Light from the Darkroom in the Royal John Russell, R.A., at the Museum of the Scottish Academy, Princess Street, Edin- January next year in the Museum of History of Science until 28 January 1996. Photography, Film and Television, burgh. Organised by Sara Stevenson, the Details in the Museum's Newsletter Curator of Photography at the National Pictureville, Bradford. This will include Sphaera, No. 2 (Autumn 1995), which film apparatus. Portrait Gallery of Scotland. There is an will appear shortly. excellent catalogue, price £12.95. 20 February 1996, Oxford 28 October 1995, Greenwich Until 22 October 1995, London Fiamsteed at Greenwich, a one day The Geometry. of War: An Exhibaion of Instruments and Illustrations, 1550-1750, at The Earth & The Heavens in the British conference at the National Maritime Library Exhibition Galleries, Great the Museum of the History of Science, Museum, Greenwich, London SEI0 9NE until 25 May 1996. Russell Street, London WCI. Open: Speakers include: J. Bennett (Oxford), M Mondays to Saturdays 10:00-17:00 Feingold (Virginia), Hester Higton hours, and Sundays 14:30-18:00 hours. (Greenwich), R. illiffe (Wellcome Insti- 28 April 1996, London Admission free. tute, London), A. Johns (University of Kent), lan Stewart (Cambridge), F. Will- The Tu~'ntieth International Antique Scien- Until 19 November 1995, Wiirzburg moth (Cambridge). Further details tele- ti~c and Medical Fair will be held at the phone Suzanne Testa: 0181-312 6747. Portman Hotel, London Wl from 10:00 to I00 Jahre R~nt~¢enstrahlen, an exhibition 16:30 hours. Details: 0181-866 86,~). celebrating the discovery of X-rays held 30 October 1995, London in the Wiirzburg Residenz (see Editorial 54 June 1996, Amsterdam/Rotterdam of previous Bulletin). The Nineteenth International Antique Scien- tific and Medical Fair will be held at the The Dutch Association for Maritime Until 30 November 1995, Montreal Portman Hotel, London WI from 10:00 to History has organised the Sccond Interna- 16:30 hours. Details from Peter Delehar: tional Congress for Maritime Historu, An exhibit The Invisible Revealed, 100 Years 0181-866 8659. hosted by the Netherlands Maritime of X-rays at the McCord Museum. Museum at Amsterdam and the Mar- Includes 70 artifacts related to X-rays, November 1995 - January 1996, Pavia itime Museum Prins Hendrik at Rotter- medicine and other related disciplines dam (see 'Announcements' in previous from collections in Montreal and Ottawa. The David M. Stewart Museum of Bulletin). Information: 1 514 398 07100. Montreal, Canada have arranged a touring exhibition of their instruments September 1996, Ottawa Until 15 December 1995, Oxford attributed to the Abb~ Jean Antoine Nollet (1700-1770). They acquired the The National Museum of Science and The Measurers: a Flemish Image of Mathe- world's largest collection of these instru- Technology, Ottawa, Canada, will host matics in the Sixteenth Century, Museum ments in 1983, many of them originating the XV Symposium of the Scientific of the History of Science, Broad Street, from the Academie de Dijon. The exhibi- Instrument Commission of the Interna- Oxford OX1 3AZ. Open weekdays 12.00- tion will then travel to Florence, Spring tional Union of the history and Philoso- 16.00, and by special appointment. 1996; Museum Boerhaave, Leiden, Sum- phy of Science. For details contact Dr Illustrated catalogue and poster avail- mer 1996; Paris Autumn 1996; London, Randall Brooks. The XVI Symposium able for £5. A series of Exhibition talks Winter 1997; and from the Spring of 1997 will be held in July 1997 in Li6ge, are organized for 6, 7, 8 and l0 it will visit sites in North America. Belgium. November, starting at 6 p.m. Note that Details from the Museum at Le Fort de from beginning of October the Museum I'le Ste-H~kane, C.P. 1200, Station A, 27 October 1996, London will be open on Saturdays from 12.00- Montreal, Canada H3C 2Y9. 16.00, but will be closed on Mondays (see The Tu¢nty-first Scientific and Medical Editorial of this issue). Tel: 01865 277280. 3 December 1995, NEC Birmingham Instrument Fair will be held at the Portman Hotel. Details as above. Until end of December 1995, Dublin An additional National Vintage Commu- nications Fair will be held at the National Details of future et~ents, meetings, exhibi- In the Colonnades Gallery of Trinity Exhibition Centre, Birmingham from tions etc. should be sent to the Editor.

Bulletin of the Scientific Instrument Society No. 46 (1995) 33 Classified

WANTED. Early Electric Motors, Advertising Charges [)vnamos & otheri~th Century Electro- .i .M~'h,mical in.,qruments. H.I~ Grevn~pan, Whole page £175 2-.~,3 M.H'., Cambridge, Mass. O213~: Half page £qO Phone tq7-253-4~82, Fax t,17-25~-gt}l I. Quarter Page £50 Eighth Page £35 I FOR SALE: Small private collection of Classified 1;0.20 per word, instruments, including a D.'atts ]'ht~t~.|t~ min. f..5 Ilt~'. [.e~els by Adie. Nt,gretti & Ct~ke Classified Box Number £1.50 per lroughton ln~.-Iinometcr~ by ~,Vatktns and insertion Taxlot Standard R l~.~ade l'k~xe~ by I've Flier, Single A4 £I00 and Cambridge Al,,o ,1 coiltwt,~n of Flier, Double A4 £125 aircraft clt~k,~ and other in.qruments Other Advertising Ask for Quotation SAI: for list- & photos. ~k~x 4~31. Artwork, if required At cost The rat~ shown are for camera ready art- 33 SIS BULLETINS- Xos I I (I)ec Iq~) work. A 10% di~ount applies on booking for to 43 I[)~'t 1~4} ¢t~ntlnuous - £40 plus 4 or more consecutive issues. Detailed Rate £7 p&p - tel tllTO3-,,c43.~g~ Card available on request. Copy Date no later than 4 weeks prior to . l~v/~. ,. " I ~/ f~6"9 7111 publication, i.e. end January, April, July & October. Bo~t Number replies to the Advertising Manager as below. Payment for advertising is due in advance with order. Payment by cheque, Visa or MC accepted. Foreign advertisers requested to use credit card paymenl~ to avoid losses to the Socielv on currency, conversion. All payments and copy details to:- Mr M.J. Cowham, The Mount, Toll, Cambridge CB3 7RL. Tel: 01223 263532/262684 Fa~: 01223 263948

Scientific Instrument Society

Tie Q Pol>ester. Golden Yellow on Dark Blue. £I0.00 plus £1.00 U.K. postage. £3.00 elsewhere.

Send your orders to. The Scientific Instrument Society., 31 High Street, Stanford in the Vale, Faringdon, Oxon SN7 8LH. Cheques pa).able to 'The Scientific Instrument Society'.

Bj6m Kambeck AI,AIN BRIEUX Microscopes 48, rue Jacob, 75(X16 Paris. France "FEI..(I)42~O219X FAX(I)42~)5524

ilislory of medicine & science. Rare i~X~ks. Grog Barhngc 67 Aulographs. Rare .~cicnlil'ic. ntcdical & surgical 31H 71 Hannoxer itIMrUltB.'liln. Big)ks of d~s:untenlalion. Tel: (~511/~A) 1748 B) appointment Bought - Sold - Apprai~d Scienti. & Medical Antiques SiS BULLETIN BINDERS

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Eighteenth and nineteenth century mathematical. ,/~rl. ~ philosophical and optical instruments of all kimls - ti~ including microscopes, telescopes, gh,bes. Scierl. orreries, sundials, compasses, sun'eying. navigating, drawing. ('ah'uh:ting. Irl~trul'r/,e~v[t~ medical ,:tad laboratory apparatus. Send $5.00 for current illustrated catalog

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Built,tin of the .'~:ientific Instrument Sooety No. 4h (1~) 3~ ® CHRISTIE'S J' FORTHCOMING SALE OF FINE SCIENTIFIC INSTRUMENTS

Wednesday 4th October, 1995 at 2.30 p.m. at CHRISTIE'S, 8 KING STREET, ST. JAMES'S, LONDON will include

th*~ rare Enghsh compot,nd m,tm,~cope s=gned I. MARSHAl l ('lrca 17 ll~; and .~ unique Itahan co,~potmd m~cn~scope slbqled and dated FRAN(;OI% BAII I ()U A MII AN L'ANNEE 1738 the carla'st n',onted m.n,s,otw b), th~s /tldk¢'r

For iI+t~.+rm.ltlon regarding this ,,.~le ples¢ contact: .lcrcmy P Colhns ENVA. gel: IH71-321 314q

(PLEASE NOTE REVISED VENUE AND DATE/TIME OF SALE) (not to scale)

® ; ,j CHRISTIE'S FORTHCOMING SALE OF GLOBES AND PLANETARIA

Wednesday 4th October 1995 at 10.30 a.m. at CHRISTIE'S SOUTH KENSINGTON 85 OLD BROMPTON ROAD, LONDON

will include

A tint' p,itr of 18m ,h,am. globe,, by (',it}': olher globes by .1dam,, (;n.,hl~.),, I Ic)'m,m, ./0/m:0n..\~'.~0., Pl.lhps .rod L~the~,: a r.|r¢ (;o~mopI,me by !.'.4/,t,~" l.h,,ll..man', all IKth ("¢'lltl.lrV (;erll|.lll PLIl|l't.lrlulll .llld ~mH]ar Ile111~,

|:(~r il|['~rllhl[IOl| rL'~.lrdlll~ lhl,, ~dJc p]C.l.,e LOlllact: J~'relm P (;~dlm. t:.~.V.A., fi'l: 'H71-321 314'~ or l~ml I ,imb (K,qg Mreet). Fe]: Ill 71-3~¢~ 215H

Bulh,hn of tl~, ~it'nlitic instrurm.nt .~ciety. No. 46 (ib'qS) CHRISTIFS A HIGHLY IMPORTANT PLANISPHERIC ASTROLABE by Erasmus Habermel for ALESSANDRO FARNESE, Duke of Parma and Piacenza, Regent of the Netherlands (b.1545 - d.1592)

to be told on 11 October 1995 at CHRISTIE'S, 8 KING STREET, ST. JAMES'S, LONDON

Signed t:.rasm,s Hah'rmd (Circa 15'~) 15in. (.tS, m ) diam. F.3tim,:te ~300,000- .~'500,IMMI

For further information regarding the sale please contact Jeremy p. Collins F.S.V.A. Tel: 0171-321 3149

Bulletin of the Scientific Instrument S<~-'iety No. 46 (1995) 37 ROGERS TL'RNER BOOKS .'irkol~h ~- .4nnqc~-~n Boobs '[~"'~

,e-~ iqd, T~ ,.~QIz ,1 o, INEW--'ION'S 0PTiC-S

2 copies now available.

3rd Edition 172-I- -£600.0()!

Earb,' .~ien¢if|c lnsmiments 4th Edition 1730 £500.00 ~ Catalogues TESSERACT issued quarterly P~,x 151 tla~tmlZ~ on Hud,~m Please contact us for further New York i07~ details. (914) 478-2594

l, • 4qIl~

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of the Profe~,~ion,Jand Science~~ I 103 WestAhso Street • 0~i, CahlomB 93023 • Telephone/Fac=ml~(805) 646-0204 Shop Open 10 am. to 5 pro. every Fr~ay, Saturday, Sunday and Monday or by app~ntment.

~14 Bulll,hn ot the ~=vntdic In,,trumvnt .~',Ot'tv No. 4~ (1995) in Denmark

maamAmml

r • • m,,,~.(:,~,,h~m 4m ~ milk.

Absn'acr

Recent years have brought a growing awareness of the imtxwtance of historic scientific instruments m the study of history and philos~q~hy of science. Since the fi~rmation in 1977 of the Scientific Instrument C~nnmision o4" the International Union of the History and Phil(~ophy of Science, an increasing number of scholars have produced studies of many aspects of mathematical and philcmq~hical historical instruments. One n~mt important aim of the Scientific Instrument Commisi~m, however, was "to stimulate the production of inventories of historic scientific instruments'. The establishment of nati~mal inventories is now under way m a number of countries, and in this international process the present listing is the Danish contribution. Aix~ut 50 collections have been visited and 2447 instruments are recorded and described The descriptions include for each insmaments its k~aticm, functkm, dimensions, material and, when Ix~sihle, its maker Relevant indices Facilitate the use of the listing for researching scholars. Although the listing will therefore be of immediate use, it will also be a basis for discussions concerning the ultimate fi~m and contents of such inventories. It is, therefore, the first important step towards a Danish national inventory. HEMMING ANDERSEN

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[-'] cop. o~ HISTORIC SCIENTIFIC INSTIIUMENTS IN DENMAIIK. ISSN 0366-3612 ISBN 87-7304-26Z-5 Price US$ 65.-/£ 40.-/DKK 350.-. Postage US$17.-/£ IO.-/DKK 90... All prices exclusive VAT.

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PLEASE CHARGE EUROCARD/MASTERCARD/ACCESS/- MIND01FAX YOUR ORDER TO: "11 Vi SA/AM.EXPRESS/DINERS MUNICSOAAIU)BOOK SERVICE| 3S NOtlll 8OEGADE I CIE]C]FIr-IDFIr-IDFIDCII--ICIDD 1016 COfqg~HAGEN K I exp. date DmNMAILK I

SIGNATURE: Are You Missing Something.• 9 like a back issue of the Bulletin.

]'he Society has now published over 46 Bulletins, each packed ssith intbrmation about scientific instruments and happenings within the Society since its Ibunding in 1983. The complete set make an invaluable Reference Library.

Man}' of these Bulletins are still available at a cost of £6.00 each plus postage.

Order by VISA or MC quoting )'our number and expiry date from:- The Scientific Instrument Society, 31 High Street, Stanlbrd in the Vale, Faringdon, Oxon SN7 81,H. ~here original Bulletins are no longer available. photocopies will be supplied.

e are one of the largest W manufacturers of brass telescopes in the United States.

A wide variety of other freely made Manufacturersof hand crafted optical and scientific instruments are produced in our 40,000 sq. ft. workshop. I00 artisans are Telescopes involved in crafting brass, silver, Kaleidoscopes wood, leather, and glass. Magnifying Glasses Wax Seals In addition to our stock items, we produce limited edition pieces, and a5 well ~,s commissioned items for public and All sorts of private museums and foundations. Philosophical Apparatub / Your inquiries are invited.

Van Cort Instruments, Inc.

29 Industrial Drive East • Northampton, MA 01060 USA • 413-586-9800 Fax 413-585-0800

40 Bulletin of the ~wntifi¢ Instrument ~)cze~ No. 46 0995) /-

Table of Contents Appropriate material will be referenced in Phys/cs Abstracts

Editorial ...... 1

~ts .oooooo...0o*o*o*oo ...... ooo.o..o,o,.,.,o.o,oo.ooo..,oo.ooo,,o..o ...... oooooo,...o..o.o, ...... 0 ...... o ...... ooo0,o...o ...... 4 ! The Birth Pains of Radio ...... A.R. Constable 6 19th Century French Scu,nt~c Instrunu,nt Makers VIII: Eugt~e Ducretet 0844-1915) ...... Paolo Brenni 12 Astrolabes and Electrotypes: An Enquiry ...... ~...... Stuart Talbot 18 'A New Kind of Rays' The Pre-history and Discovery of X-rays ...... C.N. Brown 23 F~csimi/e F//e Popov Versus Marconi: Repeating their Pioneering Experiments of 1895 ...... Ralph Barnett 27 Market Place in Germany ...... Karm Burchard 29 Book Reviews ...... 31 Current and Future Events ...... 33 Advertisements ...... 34

The Scientific Instrument Society Membership The Scientific Inset ,Society (SIS) was formed in April 1983 to bring together people with a specialist interest in scientific instnunents, ranging from precious antiques to electronic devices only recently out of production. Collectors, the antiques trade, museum staff,professional historiansand other enthusiasts will find the varied activitiesof SIS suited to their tastes. The Society has an international membership. Activities Regular evening meetings are held in London, as well as occasional one-day and week-end conferences in attractive provincial locations. Speakers are usually experts in their field, but all members are welcome to give talks. Special "behind-the-scenes' visits to museums are a useful feature. Above all, the Society's gatherings are enjoyable social occasions, providing opportunities to meet others with similar interests. The SIS Bulletin This is the Society's journal, published four times a year and sent free m members. It is attractivelyproduced and illustrated,and contains informative articles about a wide range of instruments as well as book and exhibition reviews, news of SIS activities, and meetings of related societies. There is a lively letters page, and 'mystery objects' are presented. Another feature is a classified advertisement column, and antique dealers and auction houses regularly take advertising space, so that collectors may find the Bulletin a means of adding to their collections. How to join The annual subscription is due on I January. New members are asked to pay a joining fee in addition to the annual subscription.

Current Subscription rates Subscriptions

Resident in UK £30.00

Resident elsewhere ~ f.35.00 [ $55.OO

Overseas Subscribers: Please note that higher cost is due to additional postal rates.

Pleaae contact: The Executive Officer (Wing Cmdr. Geoffi~ Bennett) 31 High Street, Stanford in the Vale, Faringdon, Oxon SN7 8LH. Tel: 01367 710223 Fax: 01367 718963 Q" •

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