ISSN 1466-3570

June 2001 No.8

NEWSLETTER of the UK SLIDE RULE CIRCLE Editor: Colin Barnes, 189 Mildenhall Road, Fordham, Ely, Cambs. CB7 5NW England Tel/Fax: 01638 720317 e-mail: [email protected]

Editorial The Blundell Archive

Peter, in his Musings , refers to the It was by happy coincidence that knowledge that can be gained from the receipt Peter Soole and my co-travellers met on board of “negative information”. I have recently the ferry crossing to Holland to attend the stumbled upon another example of this meeting at Ede last year. This meeting was regarding the history of the Otis King especially fortuitous as Peter was carrying the calculators. As a result of Richard Lyon’s last of the items destined for the “Blundell researches in the US on the subject, he was Archive” and we were able to conveniently contacted by someone who claimed to have an transfer boxes from one vehicle to the other. O-K carrying the patent number 183625. It had always been accepted that the first O-K In this last consignment are some patent was number 183723 probably issued thirty miscellaneous items and slide charts, only a matter of weeks, if not days, later. (most without identification numbers), about Richard was highly sceptical of this earlier seventy slide charts identified by “P” Number number but was later forced to eat humble pie and copyright date where known and finally and as a result contacted me to know if I knew some thirty instruction books and catalogues about this. I too, was ignorant of this number from various sources and publishers. and promptly sent my money and order to the Patent Office for a copy of 183625. Some Rather than making a blanket days later I was surprised to receive an invoice distribution to all members, it would be more duly receipted “for information only” but no economic to send copies of this up-dated list patent. Was it lost in the post? My patience on special request to anyone with a special ran out after about ten days and I called the interest. A stamped, self addressed C5 Patent Office. Initially I was told it had been envelope would be appreciated. sent but they would forward another copy. A return phone call ten minutes later advised me Membership Directory that there had been an error and that this particular patent number was “VOID”. An updated membership directory is enclosed with this issue of SS. Please advise It would seem that 183625 was never of any errors and omissions and accept our actually issued, probably having been apologies in advance. amended and issued as 183723 within a matter of days. Otis, it appears, jumped the gun in Special Thanks printing the earlier number on some of his calculators. One can only wonder at how I would like to thank all those who many of these rules were made but all were aware of my hospitalisation earlier this indications are that there were very few. year and who sent me their ‘get well’ messages. Your good wishes were very much I have always felt that slide rule appreciated - thank you. collecting was a bit like philately if one became too involved in variations but here is an example the equivalent of a stamp with the Queen’s head inverted!

© 2001 The UK Slide Rule Circle and the contributors. 1

Skid Stick Issue No.8 June, 2001

The CAL-TAPE The overall dimensions of the rule Slide Rule housing are 1¾” x 1¾” x 1”. The rule was Wayne Feely made by Cal-Tape, Roann, Indiana, and was sold or given as a promotion by the Chemical Rubber Corporation of Cleveland, Ohio. Their address has a ‘Zip Code’ which places it in time at 1963 or later. It is a cute little rule and it would be great to keep in the car to calculate gas mileage, as it takes up very little space, but I do not think I would have risked my physics final exam with it.

[This article originally appeared in the Chronicle of Early American Industries Association, March 1997, Vol. 50, No. 1 and is reprinted with the kind permission of the EAIA and the author].

Fairs and Auctions

The next International Auction to be held by David Stanley Auctions is scheduled for Sept. 29, 2001 with General Auctions on Aug. 1 and Nov 17, 2001. David Stanley Auctions EAIA photo 01530 222320 [email protected] It is perhaps the best camouflaged slide rule ever made. In the closed position it Tool Shop Auctions of Needham looks like an inexpensive utility tape measure, Market hold their International Auction on like one that you would find in a sewing box July 28, 2001 and have General Auctions on or fisherman’s tackle box. When the tape is Oct. 3 and Dec. 5, 2001. pulled from its plastic housing it is surprising Tool Shop Auctions to find that it is a 10 inch slide rule with a 01449 722992 centre tape, with B and C scales that can be [email protected] extended to act as a slide. The backing stationary tape has the corresponding A and D 31st International Antique scales on the top surface and L, K and decimal Scientific and Medical Instrument Fair will trig scales on the back surface. There is also a be held on Sunday, 28th October 2001 at the thin transparent indicator (cursor) that is Radisson SAS Portman Hotel, Portman folded so that the front and back scales can Square, London, W1. communicate. The following dates have also been announced for 2002: Sunday, 28th April Sunday, 27th October Talbot Promotions PO Box 31525, London, W11 2XY tel/fax: 02028 969 7011 email: [email protected]

EAIA photo

2 Skid Stick Issue No. 8 June, 2001

Slide rules rule OK New Members

The following article and picture appeared, A warm welcome to the following under the above banner, in “the business” new members. section of the Weekend FT dated 13 January, Paul Mezzapelle 2001 and is reprinted here with the kind PO Box 883 permission of the Weekend FT. Carmichael California, USA [email protected] It performed a useful service for the best part of 400 years. Then in 1972, Hewlett- David Bateman Packard unveiled the HP-35, a scientific 3 Withburn Close calculator that would fit in your pocket and, Wirral CH49 6QH almost overnight, the slide rule was dead. Science Museum Library But now it may be set to make a Imperial College Road comeback. The thing is that our dependence London, SW7 5NH on electronic devices has become so complete Charles Tomlinson that we are relocating many of our brain 11 Blackfriars functions to our silicon friends. According to Chester CH1 2NU research by the University of California, we Tel/Fax: 01244 318395 can’t even remember phone numbers any [email protected] more. We keep only the numbers of our Mark Butterworth nearest and dearest in our heads, the rest are 16 Batterflatts Gardens outsourced to our telephone or Palm Pilots. Stirling FK7 9JU This is why the theoretical neuro- Scotland 01786 475075 biology department at the University of Washington recommends that we start training Richard Cook children to do maths cold turkey, without their 8 Kingsdown Way calculators. They can be introduced to the New Marske Redcar slide rule, which at least requires some mental Cleveland, TS11 8JJ input. 01642 482195 The mind numbing alternative is to [email protected] lamely hand over more of our cognitive functions to machines. Dr Gloria Clifton Curator of Navigational Instruments Royal Observatory, Greenwich National Maritime Museum London SE10 9NF 020 8312 6758 fax: 020 8312 6771 [email protected]

Eugene Paulin 58 Rue Michel Welter L- 2730 Luxembourg Tel: 00352 487796 Fax: 00352 26550745

MEETINGS Hulton Getty Picture Library

[The picture would seem to show a Pilot UKSRC Meeting, Sutton, Surrey, Balloon slide rule being used by a “young” 21st April 2001 aircraftswoman in a meteorological section of the RAF. There would appear to be a second Ten intrepid visitors from as far member of the “team” in the picture. Thanks afield as the Wirral, Wales, Bolton and to Peter Hopp for this contribution.] Yorkshire joined Hugh Tidy and his wife Olwen at their home in Sutton for yet another excellent UKSRC meeting. It was so nice to

3 Skid Stick Issue No.8 June, 2001 see David Batemen and Victor Burness for had to spend a little bit of time on the “formal” their first UKSRC meeting, as well as old business of the day. hands like Jim Bready, Ray Hems, Peter Hopp, Brian Lloyd, Tom Martin, Wendy Rath, Under the chairmanship of Peter David Rees and Peter Soole who had made the Hopp we discussed and agreed the following: trip. • Next UKSRC meeting will be at the home of Dr. Brian Lloyd and his wife - theme As usual at out meetings we were of that meeting to be French and military slide impeccably hosted and royally fed and rules. Thank you for the offer Brian. watered. The majority of the day was spent • There was consensus that the UK looking at, discussing and debating the details should host the 8th International Meeting in of 20th Century English slide rules, and a October 2002 , venue either in the south of wide enough topic it is! If there was a England (Guildford or Sutton area), in the conclusion that we all seemed to agree with, it Midlands or Manchester - still to be decided. was that in all probability Stanley never made An organising committee is to be their our rectilinear slide rules - ever, and formed chaired by Jim Bready and assisted by maybe not Boucher’s calculators! They did Hugh Tidy, Ray Hems and David Bateman. however make Fuller Calculators! A Peter Hopp will notify the OS that confusing situation, but it was particularly the UK wishes to reserve the 2002 “slot”, and welcome to have amongst us someone who will also contact Manchester for confirmation worked at Stanley’s, albeit not in the slide rule or otherwise of their offer to host the next department. meeting at the Manchester Museum. David Bateman and Hugh Tidy will Memories of the day are inevitably continue to assess suitable venues within a different for each of us. For me it included: tentative budget of 50 delegates and a the whole family of “Mechanical Engineers” programme starting Friday p.m. and finishing calculators - there appears to be three sizes not Saturday night, with an obvious associated the two as originally thought, several activity for the Sunday. “Scientific Publishing” examples and the • Ray Hems was asked to arrange the inevitable collection of other Fowler’s. An best swap he could with appropriate parties in amazing variety of Fuller’s from an undated the USA for our stock of Blundell rules, so but obviously very early model through to a that the UKSRC membership could benefit Bakerlite example, with widely differing from an American Pickett rule - say pointers showed how this calculator evolved • Best wishes were sent to the absent over the years. The mouth watering array of Colin Barnes for a speedy recovery from his early boxwood rules (OK, they may not have sojourn in hospital. been 20th Century) covering all types of • A rousing vote of thanks was given calculation from timber contenting via all to Hugh and Olwen for being such marvellous types of alcohol and gauging, engineering and and generous hosts. the wool trade, to the more esoteric calculation of humidity. A Mk 1 Pilot Balloon rule, plus 7th International Slide Rule dip rods, cask gauges and many more items of Meeting, September 14 - 16, 2001, Munich great interest were duly looked at and (IM 2001) A reminder that this meeting, to be discussed. Coincidence - never far away at held at the Deutsches Museum, Munich is fast these meetings - both Peter Hopp and Jim approaching and attendance registration Bready waving around identical Negretti & should be made well in advance. Zambra sling hydrometers (with slide rule) , Registration and further information both purchased the previous day, one from from: Klaus Kuehn Portobello, the other from Needham Market, Postfach 1210 (at widely differing prices). Highly erudite D - 82194 Groebenzell conversations such as: The use of π as a Germany method of identifying makers, (this may yet tel: ++49 (0) 8142 52741 turn into an article for the Gazette); The use of fax: ++49 (0) 8142 593354 various gauging devices as illustrated in an old email: [email protected] photograph of gaugers at work in the Port of London (also a future article); Solution of quadratics, quartics (bi-quadratics) by slide rule; Identifying ivory, bone or plastic. This was all extremely pleasurable, and then we

4 Skid Stick Issue No. 8 June, 2001

lectures to working men” , Wyman & Sons, UKSRC Autumn Meeting London, 1899) Sunday, October 21, 2001 The Preface to the 1st edition of the Dr Brian Lloyd and his wife, German translation mentions that Perry quoted Reinhild, have kindly offered to host our next the words of that great scientist, Lord Kelvin meeting at his home in Oxford. It is planned of Largs, “... there is no useful mathematical that the meeting should get under way at about weapon, which an engineer may not learn to 10.30/11.00am and, as is customary, an use.” Perhaps Lord Kelvin considered the attendance charge of £3.00 is requested to slide rule to be one of these “weapons” , cover the cost of lunch. Ample car parking is clearly Professor Perry did. As we know John available. Perry designed the Perry slide rule (1908) made by A. G. Thornton, Manchester and In addition to our general business, mentioned by both Cajori ( Perry’s New Slide which will not doubt include thoughts for our Rul e, 1908) and Pickworth ( The Perry Log-log next International Meeting, the proposed Rule ). theme for the meeting will be French and military slide rules and Brian advises that he Dieter von Jezierski has plenty of table display space so let’s have a good selection of examples. Sir,

Please contact Brian at least two May I caution members against weeks in advance of the meeting indicating keeping slide rules in leather cases; the your expected attendance, your required chemicals used in tanning the leather may display table space and advising if you have attack the metal parts. This does not appear to any special dietary needs. A location map is be a universal phenomena but when it strikes included with this newsletter. it can be disastrous. Dr Brian Lloyd Here are some examples: High Wall • The most serious is with a K&E 5” Pullen’s Lane Jet-log Junior. This rule was never used and Oxford OX3 0BX was left in its leather case for ten years. I was tel: 01865 763353 distraught to find that severe corrosion of the metal fittings that hold the stock apart had occurred. Minor corrosion was also present Letters to the Editor on the cursor. • The cursor on another rule showed Sir, some corrosion on the frame. This cursor was not the original and was obtained as a best fit In an antiquarian bookshop here in replacement in the 1950’s. Germany, I found a copy of “Höhere • The cursor on a 5” DIWA rule gets a Mathematik für Ingenieure” , 3rd edition, greasy deposit on it after a few weeks in its 1919. The first German edition of this book case. appeared in 1902. • A Halden Calculex showed some “Höhere Mathematik für Ingenieure” corrosion after being kept in its case for an is a translation of the famous book “The unknown number of years. Calculus for Engineers” by Dr. John Perry Problems seem to occur on rules that F.R.S., Prof. of Mechanics and Mathematics at have not been removed from their cases for a the Royal College of Science, London. The number of years so it may take a few years to first English edition is dated 189 7, develop.

John Perry was first of all an Gerald Stancey engineer, but he should also be recognised for his efforts to impart a knowledge of Sir, mathematics to engineers in England around the turn of the century. He also held evening John Knott’s views on the difference lectures for workers about mathematical tools. between a slide rule and a slide chart are of (See Practical Mathematics, “Summary of six particular interest as I have been engaged in selling both. My early days in the slide rule industry were dominated by the development

5 Skid Stick Issue No.8 June, 2001 and sales of slide rules and then gradually Musings slide charts and disc calculators took over. Peter Hopp Slide rules usually have logarithmic scales but sometimes non logarithmic scales. I get enormous pleasure (and not a Slide charts and discs often have logarithmic little frustration) researching the various topics scales and also have numerical data. I end up writing about. However, research takes time and hence I have multitudes of A slide rule is a traditional instru- “projects” on the go at any one time, each ment either with a solid back or the later waiting for some break-through on the lightweight type with bridge pieces tying the research front to enable continuation or two outer parts together. It will have central completion. A very great part of the pleasure tongues and grooves using material thick stems from the help and generosity of fellow enough to accommodate these features and collectors, a topic that I frequently bang on normally grooves for a cursor or runner. Most about, and will continue to do so! However, slide rules were standard and featured in the knowledge and experience passed on does catalogues although some “specials” were not have to be positive and new. It is equally made to order. valuable to a researcher when someone is kind enough to pass on something not so positive. A slide chart is lightweight and almost never has a cursor. It has a front and An example of this was my recent back plate held together either by separating request for help on tests for ivory, bone and edge strips or by folding. The slide is a flat plastic. A Skid Stick reader was extremely piece of material. Card slide charts normally kind with a response which did not produce a have windows formed by punched slots and magic unguent that could be dropped onto the plastic slide charts by using transparent sample and turn the appropriate colour per material printed solid colour with the widows substance, but mirrored my own frustration in left clear. All designs are special purpose. NOT being able to get so-called definite tests to be definitive! This response was as A disc calculator uses the same valuable to me as a positive one. It showed material as linear slide charts and the principle that if I was being obtuse or cynical in my market for both is as a promotional product. view of certain “ivory” examples (my own included) then someone else was seeing the Traditional slide rules ceased general same problems! A subsequent phone call was production about 1975 although Blundell most enjoyable. We exchanged frustrations Harling were still making a humidity slide and I learnt a term coined by him for such rule, in occasional batches, up to 1998 using devices: “Ivorish” . This is brilliant and so the Super Duplex construction. Several perfectly describes what a lot of people would manufacturers are still making slide charts and hope is ivory, but in all probability is bone, discs in considerable quantities. and may even be plastic! Many thanks Peter Soole Michael for the help and an excellent new IWA - UK term! I guess that a number of us have “Ivorish” devices in our collections! Sir, “When is a slide rule not a slide May I bring to your attention the rule?” seems to have struck a chord! It is following notice that may have escaped your always most enjoyable when something we notice. write prompts a response - keep them coming! Brit. Soc. Hist. Maths. Newsletter 42 However, I do not think I will venture further Winter 2000, pp21 & 22. opinions after my “chicken” definition. (SS Math. Gazetteer of Britain #15, London Part No. 6) 4: Science Museum. • “the earliest known straight slide Question: How do you get caked-on rule (1654)” “finger goo” off a slide rule? I have my own • “a remarkable collection of other pet methods but would be interested to hear slide rules ...” other people do it. I will collate ideas for a All in ‘Computing then and now’ gallery . future edition of Skid Stick - let me know please. George Duckworth

6 Skid Stick Issue No. 8 June, 2001

Dieter von Jezierski raises a most interesting point in his letter (Letters to the Editor). The training of engineers (or the public in general for that matter) in the “weapons of maths” continues to be a vexed question as evidenced in recent newspaper articles. These show that a frighteningly large part of the population is “innumerate” and that there has been little or no improvement despite a multitude of “initiatives”. The use of the slide rule has always been considered by some people as “difficult” and there are quotes from Flower (1768) to Snodgrass (1955) to prove the point over the years. I’m sure there are further examples of this thinking across Europe and the USA, let me know of any I cut my computing teeth on the examples you know of. Marconi equivalent of the Elliot 403 (which probably had less power than the simplest 286 Victor Burness (excellent chap) PC), and was a lot more cranky to use. It just recently sent me an article from the 1960’s on shows that computers did bring real lens design as it included a picture of Gordon efficiencies, we still just have to learn how to H. Cook, chief lens designer for Taylor, make the best of them! Taylor & Hobson using a Fuller slide rule. The article was particularly interesting as it The picture of Gordon Cook from the included comparative information on lens article is a worthy subject to complete this design calculations using slide rule (Fuller), Musing, note the incredibly tidy desk and computer (Elliot 403) and desk calculator to office (posed?) and the way he is holding the calculate the 7 main aberrations through a lens Fuller. My thanks to Cooke Optics Limited (one or several glass components in an optical of Leicester for permission to use this image. system) using about 40 “Rays” (thin pencils of light) for a high quality photographic lens with up to 6 glasses (12 surfaces). Taking account of the required accuracy - 9 decimal places - Bookworm we can see that the slide rule (Fuller) was only useable for a simplified “Primary Analysis” as Mathematics Galore! Masterclasses, it could only provide answers to 5 decimal Workshops and Team Projects in places. The comparative figures are as Mathematics and its Applications. follows: By C. J. Budd and C. J. Sangwin. • By desk calculator: 4 mins per ray; Oxford University Press. i.e. 160 mins per “face”; 1920 mins (32 hrs) 288 page, 10 halftones,217 line illustrations. per 6-glass lens. ISBN: 0-19-850770-4 (Paperback) £14.95 • By computer: 0.66 secs per ray; i.e. ISBN: 0-19-850769-0 (Hardback) £35.00 26.4 secs per “face”; 316 secs (5 mins) per 6- glass lens. Circle member Chris Sangwin of the • By slide rule; 40 mins for a School of Mathematics and Statistics, simplified analysis. University of Birmingham and his colleague Chris Budd, Professor of Applied This is a considerable oversimplifi- Mathematics, University of Bath and ication; an improvement of 200 is more Professor of Mathematics, Royal Institution reasonable. “Input” and “output” from the have written this book aimed at enlightening computer was difficult as I can well young students from age thirteen and remember. stretching those of a more mature and experienced vintage.

Quoting from the OUP promotional literature “This book is a series of self- contained workshops in mathematics, which aim to enthuse and inspire young people, their

7 Skid Stick Issue No.8 June, 2001 parents and teachers with the joy and increase accuracy. Sadly, for slide rule excitement of modern mathematics. Written in aficionados, it is primarily told within an an informative style, each chapter describes astronomical context rather than a calculating how novel mathematical ideas relate directly context. Our thanks to Gerald Stancey for to real life. The chapters contain both a bringing this book to our attention. description of the mathematics and its applications together with problem sheets, Slide Rule Papers presented at the their solutions and ideas for further work, “Symposium on the Development of Cal- project and field trips. Topics include; mazes, culator Technology” Ernst-Moritz-Arndt folk dancing, sundials, magic, castles, codes, University, Institute for Mathematics and number systems and slide rules”. Computer Science, Greifswald, Germany, September 2000. Your reviewer has not had the By Heinz Joss and Georg Schreiber. opportunity to see the complete book but I English translation published by the UKSRC have studied the 28 page chapter covering the A4, approx. 33 pages. subject of slide rules from the history of ISBN 0 9535039 2 5 logarithms through to linear and circular This volume includes two papers on “make-it-yourself” slide rules. Based on this I slide rules, translated into English, presented am sure that readers will find the book an last year in Greifswald, Germany. interesting and informative addition to the • The first paper Drum Slide Rules - mathematician’s bookshelf. Slide rules with long scales was presented by Heinz Joss. It is a comprehensive, if not definitive, survey of drum slide rules mainly originating from Switzerland and Germany. The paper provides tables of recorded examples and is superbly illustrated with some 50 colour pictures. • The second paper by Georg Schreiber is titled Slide Rules from Dresden & Bad Liebenwerda. This article covers rules from the former East German companies trading under the names Reiss, Löbker, Meissner and VEB Mantissa. Again the paper is well illustrated with colour pictures of a number of typical models.

This work is currently in preparation and due for publication prior to the next International Meeting in Munich. Details of availability and price will be notified in due

course.

Chris Sangwin would welcome comments from readers by email or post. Slide Rule Gazette, Issue 2 [email protected] Published by the UKSRC Home Page ISSN 1472-0000 www.mat.bham.ac.uk/C.J.Sangwin/ £10.00 + £1.00 p&p (UK)

Dividing the Circle. The Development of Our second Slide Rule Gazette is Critical Angular Measurement in now well into production and publication is Astronomy 1500 - 1850. planned for August/September this year. By Alan Chapman; John Wiley & Sons, & Among this year’s articles are items Praxis Publishing. 2nd Edition, 1995. on: ISBN 0 471 96169 8 Circular Calculators by Fearns and Mear. This book covers the early days of Simplon Slide Rules circular dividing, the development of dividing An Early Chinese Slide Rule engines and the various other contributory The ‘Sintalator’ technological developments such as A Classic Author microscopes and telescopes which helped to

8 Skid Stick Issue No. 8 June, 2001

Sheppards Improvements to Slide Rules Slide Rules and the Internet Chemical Slide Rules Meteorological Slide Rules Ron Manley Perry and Walther - pioneers of engineering mathematics This time, rather than give an Hyperbolic Functions on Slide Rules overview as I have done in the past, I’ll The “Marconi” Slide Rule concentrate on two of the largest sites related “Nelson uses Gunter” to slide rules on the Internet - that of Sphere Florian Cajori Research and my own. Solving Equations Which one is Gunter? Sphere Research is a Canadian Further details to follow but advance orders company which in addition to high tech are welcome and copies will be despatched on research and development also sells slide publication. rules. Their site is a commercial one.

very ‘Allo ‘Allo They have five main areas related to slide rules: • 1. Buying a slide rule. In a small French village, Brocante , I They have a range of new rules for sale. spotted La Règle a Calcul guide by Raymond Prices are generally higher than on ebay. For Dudin and published by Dunod. According to an FC 2/83N the price of US$295 is the introduction, Dudin was a great fan of the comparable to ebay but the price for an Aristo slide rule. However, before launching into Studio 968 at $195 is a factor of 2 or 3 higher how to use a wide variety of scales, came a than ebay. There are few British rules for chapter on; Historique de la Règle . Well it sale. The only one at present is a Blundell 800 seems slide rule history is a little more French Manheim at $39. Being North American there than any of us knew! is a big selection of Pickett rules. There is also a section on cheap rules. The cheapest is The opening paragraph started: a Sterling Mannheim at $15 - the Sterlings “C’est a JEAN NEPER (1550-1617), really were at the bottom of the market. mathématicien écossais, que l’on doit • 2. Care and operate slide rules. l’invention des logarithmes”. A later The instructions are stored as graphical images paragraph went on to expound: “C’est un of slide rule manuals. These are typically autre mathématicien anglais, EDMOND quite large. A 64 page Hemmi manual for a GUNTER (1581-1626) qui eut, trois and après chemical rule comes to 2.3Mb which, unless la parution des logarithmes, ....”. Apart from you have a fast connection, would take quite a a minor mention of Briggs, this potted version while to download. of history finds only two other figures warrant • 3. Archive of manufacturers. recording - who else but Etienne Lenoir and For many collectors the most interesting area Amédéé Mannheim. is the slide rules’ archive. The makers covered are: Aristo, Blundell-Harling, Faber- I can almost hear René Artois saying Castell, Flying Fish, Graphoplex, Hemmi, to Edith: “it is that stupid Englishman Hughes-Owen/Geotech, Keuffel & Esser, Crabtree trying to speak French again; he Nestler, Pickett, Post and Staedtler plus a few means Jean Napiér and Edmond Guntér!” other sections on things like circular rules. For each maker there is a short history of the historical note: Dudin , from the company and details of a selection of their L’École supérieure d’Électricité de Paris , rules. The Blundell-Harling archive, for made his guide impartial, favouring generic example, has a copy of a catalogue and details diagrams of rules rather than depicting those of ten of their rules. Not comprehensive but of a particular manufacturer. However, his still interesting. The Keuffel & Esser archive notation for the Reciprocal scale was “R”. by contrast has details of around 100 rules. This suggests this “old style” notation was still • The other two sections are links to prevalent in France when this guide was other sites and copies of press comments on published in 1947. their site. There are about ten links to other David Rance sites and mentions in the press include the New York Times.

9 Skid Stick Issue No.8 June, 2001

My own site has six sections: The addresses of the sites are: • 1. Instructions. http://www.sphere.bc.ca/test/suniverse.html This includes an A-to-Z of slide rules which I http://www.sliderules.clara.net have written myself; most of the book “Teach Yourself the Slide Rule” (with permission of the copyright holder) and almost 20 The Agnew Slide Rule instruction manuals. The A-to-Z has details of the common operations also specials on John Knott commercial, electrical and electronic rules. The instruction manuals include the Otis King There are many ways by which a and Fowler as well as more standard rules collector can acquire items and gems for his such as the Faber-Castell 2/83N. There are collection. One of the most gratifying, is also manuals in French, German and Spanish. when a friend or acquaintance, offers an item Many of the manuals are in PDF format. For (in this case a slide rule) which has been used this the manuals were first scanned and all the working life of a close relative. It is converted to text and graphics. Although this sometimes possible to obtain useful is time consuming, for me, it makes the information on the life of the item which will resulting files much smaller. For example, the augment its history. This is how I acquired Teach Yourself book is only 400k. Whilst the the ‘Agnew’ slide rule. book is about three times the length of the manual mentioned above at the Sphere This rule was given to me by the wife Research site, the file is only 1/5th of the size. of the original owner who had used it for most • 2. The next section is on slide rule of his working life at a Manchester cloth and prices. Every month I analyse and publish the shipping company. The description is as prices of rules sold on ebay, the internet follows: auction. I’ve been doing this for 18 months Made of boxwood and hand marked, and every month about 2000 rules are sold. 23 inches long by 2 inches wide and 5/16th’s Whilst many of the rules are, as might be inches thick - one slide - no cursor. Scales expected, Picketts and K & Es, many rare marked on one side only, made by J Casartelli rules are also sold on the site. & Son Ltd., 18 Brown Street, Manchester. • 3. I’ve also got a lot of the rules from my collection on the site with pictures The scales are marked A -B,C - D (see Fig. 1) and descriptions plus a few rules which I don’t own but for which I been sent pictures and A scale = Width of cloth in inches from 10 to details. 60 marked from right to left and • 4. The next section is on sources of offset from the other scales. slide rules. With links to those who sell rules B scale = Weight in grams/square metre, and some background information on where to grams/linear metre and kilos/1000 buy rules - including a warning of what to be yards. Marked 10 to 700. careful of when using ebay. C scale = Weight in pounds (lbs) and ounces • 5. The next section, called “other (ozs). Marked from 1 to 70. resources” is a bit of a mixture but includes D scale = Length of cloth in yards. Marked links to other sites, details of collectors’ from 10 to 700 organisations and details of the Slide Rule CD The radius of the scales is the same in each produced by Herman Herwijnen of the Dutch case. slide rule circle. It also includes the UKSRC site. Scale A starts at a point 15.5 inches • 6. The final section is called from the right hand side of 10 on the B scale. “International” and provides another way for An arrow E is marked on scale A at a point non-English speakers to find the foreign above and coinciding with 43.349 (No. of language manuals. kilos in 1000 lbs.) on the B scale when the left hand indices of scales B, C and D are aligned. Whilst I can’t yet boast the number of press comments that the Sphere Research site has, my site was recently selected for a full page review by Internet Magazine.

10 Skid Stick Issue No. 8 June, 2001

A bale of cloth of inches width, yards length and lbs. weight, when set on the slide rule will give, at one setting, the following information: 1. grams/square metre 2. grams/linear metre 3. kilos/1000 yards 4. ozs./yard It can therefore be deduced, that by using any weight shown, along with the width and length, the other weight value can be calculated.

The rule can also easily convert Imperial to metric weights and measures.

Example (Fig. 2) A bale of cloth 36 inches wide is 70 yards long and weighs 8¾ lbs. Place 8¾ on scale C above 70 on scale D then:- The weight in grams/square metre is 68 read on scale B below and coinciding with 36 (the width) on scale C. The weight in grams/linear metre is 62 read on scale B below arrow F on scale A. The weight in kilos/1000 yards is 57 read on scale B below arrow E on scale A. The weight in ozs/yard 2 is read on scale C above the arrow G on scale D.

[Copies of patent available on request.]

HELP! British Patent Office Marks

I am researching these and was Fig. 1 Fig. 2 wondering whether anyone has come across

them on a slide rule, slide rule box or other

ephemera. An indication arrow F is marked on scale A at a point equivalent to 39.37 (inches in 1 metre). An indication arrow G is marked on scale D at a point 16 (ozs in 1 lb).

This slide rule was patented in 1913 by Richard Fletcher Agnew of Moston,

Manchester (Patent No. 22165). It claims that five results can be read after one movement of The triangular mark was used the one slide. between 1842 and 1883, British Registered It claims to convert with one Design ( Rd. or Rd.No. ) Numbers were used movement of the slide: through to 1960 and possibly later. Please let Lbs, ozs and yards to grams/square metre me know if you have come across such “ “ “ to grams/linear metre information on a slide rule, and a copy of the “ “ “ to kilos/1000 yards mark, please. Grams/square metre to grams/linear metre Peter Hopp “ “ kilos/1000 yards

Grams/linear metre to kilos/1000 yards

11 Skid Stick Issue No.8 June, 2001

Demonstration Rule A Strange Set of Scales

An enquiry has been received from Peter Hopp Dr. David Ponick, Professor Emeritus, University of Wisconsin. Can anyone shed A recent very pleasing acquisition any light on the possible origin and delighted me when I bought it, the Timex manufacture of the demonstration rule Indiglow with the slide rule bezel was cheap, described below. it worked and it did have a slide rule! See Fig. 1. The Indiglow light is most impressive The slide rule comes from the estate under the bedclothes! I was slightly irritated of a former schoolteacher on Prince Edward when I found (before I bought it) that the Island, Canada. The rule 73 inches long, 8 bezel has click stops and only rotates anti- inches wide and 1½ inches thick. The cursor clockwise (why do they do this? Can anyone is a replacement (home made?) and, unless it help?) but I thought “so what” and proudly was on the original cursor, there is no wore it home. indication of the manufacturer. The scale layout is the normal A/B, CI, C/D, K and is so marked. The age of the rule is unknown but the deep, rich patina suggests the early part of the 20th century. Apart from a few surface scratches and ‘dings’ the rule is in remarkably good condition.

Figure 1: Timex Indiglow

A careful study with a jeweller’s loupe - the only way for the aged to work the scales - then revealed the scale markings inside the rule between 30 and 35 has 12 divisions (the halves are marked) not 10 as would be normal and which match the markings on the bezel! This prompted a more detailed examination of the other cheap watch slide rule that I have.

Any information can be sent via the Editor or direct to: Dr David A Ponick 5462 Chokecherry Road Eau Claire WI 54701 USA

Figure 2: Mercedes

12 Skid Stick Issue No. 8 June, 2001

• Breitling Chinese copy. A very The following extract does seem good copy, the divisions are logical, i.e. they worthy of reproduction here: have the right number of subdivisions, but “ ... humbly presented unto His Majesty coincidence between C/D scales is not very (George II) that I had, with much labour and good in places. The bezel is freely rotating. expence, invented and contrived “An • Citizen . This has logical divisions Instrument which was then brought to its and coincidence between C/D is good but not Utmost Perfection, to be called The perfect. This is not surprising as both scales Catholicorganon or Universal Sliding Foot are on external bezels, one fixed the other Rule, which consisted of a Stock that freely rotating. contained an Octagonal Slide or Telescope • Mercedes . This was the cheapest and two Thin Slides, each Slide containing a and when I bought new I had already realised Brass Tongue, that form a Quadrant, which that the subsidiary dials on the watch had would be of great Use in the Practice of stuck-on hands, which was interesting in Arithmetick, Geometry, Mensuration, itself! See Fig. 2. The slide rule scales are Gauging, Trigonometry, Navigation, Dialling, something else, the external bezel is logical, Astronomy, and all the Branches of the the internal is unbelievable with divisions and Mathematicks, being an Instrument never numbers almost at random, any coincidence discovered or made use of by any other between C/D is purely fortuitous! The bezel is Person or Persons whatever, and would be of also click-stopped and only rotates anti- great Service to many of His Majestie’s clockwise. Subjects who were desirous of being improved, constructed, or assisted in the It is interesting that all examples above Studies;” (apart form the Mercedes) can be used for calculation within the sort of accuracy that might be expected from such a small device Special Offer with rather thick markings. On the Timex, because the markings are within the arc that is Notification has been received of a required for 30-35, general accuracy is special subscription rate available to members adequate, except when calculating using of the UKSRC for Collect it! magazine. anything within the arc - what do you use as Members of the UKSRC are offered an annual 35 say, one less than 35 or four up to 30? subscription rate of £27.00 giving a saving of Where initially I had thought this was a good £4.20 for twelve issues. This offer is valid old-fashioned cock-up, and so it may be on the until August 1st and subscriptions may be Timex, I now realise that in many cases the made by credit card on telephone number scales are purely ornamental. But why 01189 737 888 or by cheque sent to the produce stupid scales when it must be almost address below. Please quote “Club 1” to as easy to produce sensible logarithmic scales? benefit from this offer and note that the Ideas please! original closing date was the 1st July but this has been specially extended to the UKSRC so that reasonable notification could be included PATENTS in this issue of our newsletter.

An interesting addition to our Patent “Collect it!” magazine carries many Library and earliest to date is: features on affordable collectables and latest No. Date Description prices from the auction rooms. Regular 676 1753 Combination of Sliding Foot features include news from collectors clubs Rule, Telescope, Quadrant, and the “Collectors Club Focus” giving clubs &c. an in depth coverage. Information regarding Suxspeach the UKSRC has been submitted to the Unfortunately there is no drawing magazine. attached to this document which was printed Collect it! in 1865 having been copied (one assumes) Unit 11 Weller Drive from the original hand written version. Hogwood Lane Industrial Estate Finchampstead Berkshire, RG40 4QZ www.collectit.co.uk

13 Skid Stick Issue No.8 June, 2001

Elstree Aerodrome Custom Made Slide Rules Herts. WD6 3AW www.pooleys.com A spin off from Chris Sangwin’s book, “Mathematics Galore” has been an enquiry from a US company about the use of Offered for Sale the design of the circular slide rule for commercial manufacture as a promotional An Otis King in virtually mint “give away” item. condition is offered for sale to members of the Chris advises that he can produce UKSRC. This rule is a Model ‘K’ and carries copies and adapt the slide rule illustrations the serial number A 5035 (second issue of fairly easily and if UKSRC members have prefix ‘A’ dated approx 1970). The rule is specific requests for bespoke slide rules he’d complete with box, leather sheath and be happy to oblige. Logos can be instructions. incorporated. (Meeting 2002 Committee Please contact: David Robinson please note!) Tel: 01925 824752 [email protected]

New “Slide Rules” MIR 28

John Seago brings to our attention a Mededelingen en Informatie voor range of flight computers and other aviation Rekenlilialenverzamelaars. May 2001 related calculators that are available from The newsletter of the KRING, the Dutch Pooleys Flight Equipment Limited. Circle of Slide Rule Collectors

Table of Contents Who does What? ...... 3 From the Editor Simon van der Salm ...... 3 Dennert & Pape Jubilee Book IJzebrand Shuitema ...... 5 International Meeting 2000, Ede Chris Hakkaart ...... 7 Gauge Marks on Electro Slide Rules Simon van der Salm ...... 8 Calculating on slide rule and disk Chris Hakkaart ...... 12 Home meeting at Harrie van Dooren Chris Hakkaart ...... 13 Public Relations Chris Hakkaart ...... 14 A website for the Dutch Circle Chris Hakkaart ...... 16 A range of flight computers is Kring Annual Meeting available for commercial, student, private and Chris Hakkaart ...... 17 microlight pilots. Notable in the range of New in the Collection: A Faber-Castell some 15 computers and calculators is the Electro 378 Aviat 617 by Dennert & Pape. The others are Simon van der Salm ...... 18 of unknown manufacture but appear to carry OS Journal, Vol 10, No1: Contents ...... 21 the Pooley name. In addition there are 4 SS No.7: Contents ...... 22 classroom demonstration computers listed in International Meeting: Munich, the catalogue and an Iteractive Training CD 2001 ...... 23 Rom. Prices range from about £10.00 up to New Members ...... 26 nearly £400.00 for a demonstration model Collectors Fair in Utrecht with stand. Simon van der Salm ...... 27 Books about Slide Rules Pooley’s catalogue is available from IJzebrand Shuitema ...... 31 Pooleys Flight Equipment Limited:

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