Obituary.] ARTHUR CROUCH FOLKBED. 365 as3,000 men under his control. Hedesigned and carriedoutimprove- ments in theharbours of Ja8na and Point Pedro;a bridge, 950 feet in length, across tlie Vamatipulam, and smaller bridges varyingin length from 50 feet to 180 feet; and by judicious drainagehe afforded great relief to the Jaffna district, which had been flooded annually to a depth of 2 feet to3 feet. Independently of his work under Government, Mr. Folkard acted as manager of the Colombo and Madras SteamShipping Company, whilefor the Ceylon Company hedesigned andarranged for thecarrying- out of a system of light locomotive lines to the interior of the island. In 1869 Mr. Folkard resigned the service of the Public Works Departmentand practically retired from the profession. About four years later be returnedto England and took up his residence in London, writing occasionally for the technical press and re- maining a constant correspondent of the Ceylon Observer. In 1873 he designed an improved apparatus for loweringand raising, engagingand disengaging ships’ boats, whichhe described to theUnited Service Institutionin the following year.’Mr. Folkard died at his residence, 2 Portman Nansions, Baker Street, on the 26th December, 1896, from pneumonia. He was elected an Associate on the 2nd Nay, 1865, and was transferred to the class of Xember on the 7th December, 1869. JAXES HENRYGREATHEAD was born at Grahamstown, Cape Colony, on the 6th August, 1844. His death has cut short a career to which the future seemed to have assured great success and high professional distinction. His early years were spent in his native place, which he left to come to England in 1859 for the completion of his education, and in 1861 began a three-years’ pupilage to the late Nr. Peter W.Barlow, M. Inst. C.E. On the expiration of that term, he was e~gagedfor a year as an assistant engineer on the construction of the Midland Railway extension from Bedford to London, under Mr. W. H. Barlow, afterwardsPresident, and Mr. C. B. Baker, 31. Inst. C.E. About this time his old master,Peter Barlow, was bringing before the public a comprehensive scheme for the relief of London Jonrnal of thc Bop1 United Service Iustitution, vol. sviii. p. 2;s. Downloaded by [] on [11/09/16]. Copyright © ICE Publishing, all rights reserved. 366 JANES HENRY GREATHEAD. [Obituary. street traffic by the construction of underground railways running in cast-iron tubes, constructed by means of shields, and to which access was to be afforded by shafts and hydraulic lifts, and the tunnelunder the Thames which is knownas the TowerSub- waywas first undertaken as “ a sample of the system.”l The earlier success of Brunel in constructingthe Thames Tunnel at Wapping had beenachieved despite thevast physical diffi- culties incident to the method of construction an6 the appliances then available. The disastrousexperiences of that undertaking, completed throughthe unrivalled skill and courage of its engineer, wereindeed so notorious that,twenty-six years later, no contractor was found willing to execute the projected Tower Subway,though its sectional area of excavation wasonly one- twentieththat of the former tunnel. Mr. Peter Barlow, the Chairman of theTower Subway Company, whose son was engineer for the works, had, however, full confidence inthe shield system of tunnelling when coupled with iron tubes, and indeed, in 1839, when it was proposed to abandon Brunel’s shield system at the Thames Tunnel, Professor Peter Barlow reported strongly against such a course, so that successive generations of the Barlows were advocates of the shield system.2 In this con- dition of affairs, Mr. Greathead, although only twenty-four years of age, tendered for the construction of the Tower Subway and shafts for a sum of 59,400, and Mr. Barlow recommended the acceptance of his tender-a circumstance which testifies both to the judgment and foresight evinced by the engineer and to the con- fidence of his former pupil in his ability to carry to a successful issue SO onerous a responsibility. The work was begun in 1869, the driving-apparatus adopted being a cylindricalwrought-iron shield forced forwardsby six powerful screws as thematerial was excavated infront of it. The lining of thetunnel, the internal diameter of whichwas 6 feet 7 inohes, was formed of cast-iron segments bolted together, and grout wasforced into the space left by the shield between the soil and the lining. It is interesting to observe that the working- opening in the diaphragm forming the frontof the shieldemployed by Mr. Greathead is described as having extended to within a few inches of the top 3; though Mr. Barlow had, in 1868, devised a shield in which the working-opening was LL through or below its 1 The flmes, 2 Dec., 1869. * ‘‘ Life of Brunel,” Beamish, p. 279. 3 Minutes of Proceedings Inst. C.E., vol. cxxiii. p. 56. Downloaded by [] on [11/09/16]. Copyright © ICE Publishing, all rights reserved. Obituary.] JAMES HENRY GREATHEAD. 367 centre,” with a view to the exclusion of water from the upper half of the tunnel by the applicationof compressed air, if circumstances should necessitate such a proceeding. The value of the principle involved in the employment of compressed air under such con- ditions had been recognised even earlier, and this was one of the steps leading to its adaptation to practical conditions. The strata traversed, however, were sufficiently impervious to render the use of compressed air unnecessary, and the subway was successfully completed in 1869. In the following year Mr. Greathead began practice on his own account, and evidence exists to show that his active intelligence continued for some time to exercise itself upon the generalproblem, a particular case of which it had fallen to his lotto solve so success- fully. In 1871 he devised andthree years afterwards patented apparatus for tunnelling by the action of currents of water upon the material in frontof the shield, but the system hasadvanced not beyond the experimental stage. In 1873 Mr. Greatheadreturned to his earlier occupation of railway-construction, and during thefour following years acted as resident engineeron the Hammersmith Extension Railway and the Richmond Extension of the Metropolitan District Railway. About thistime also he wasengaged in devisingplant for tunnellingthrough the water-bearing strata of the bed of the Thames at Woolwich. Herehe introduced an improvement in the shape of an air-lock near the face of the shield, formed as a trap to prevent theloss of any large quantityof air in the event of a blow ’’ occurring through the strata infront. Unfortunately, perhaps, the contrivances, worked out in elaborate detail by their designer,were insufficiently tried in the first instance, and an attempt to drive the tunnel at a lower level without their laid proved abortive and led to its abandonment in1876.2 Duringseveral succeeding years no opportunity presented itself for Mr. Greathead to exhibit the superior talent indicated inhis earlier career and proved byhis more recent achieve- ments. He indeed assistedin the preparationof several well-known projects-the Regent’s CanalRailway in 1880, the Dagenham Dock and the Metropolitan Outer Circle Railway in 1881, a new line between London and Eastbourne in 1883, and various Irish light railways in1884-whilst his inventive talent found employ- ment in devising improvements in roller-skates,locking-nuts, Minutes of Proceedings Inst. C.E., vol. cxxiii. p. 77. Ibid, p. 57. Downloaded by [] on [11/09/16]. Copyright © ICE Publishing, all rights reserved. 368 JANESGREATHEAD. HENRY [Obituary. hydraulic-apparatus and hydrants. The “ Ejector ” hydrant, which heintroduced, in conjunction with Mr. N. D. Martindale,is probably the most substantial of these inventions. In 1884 Mr. Greathead was engaged as engineer in obtaining the Act for the “London (City) and Southwark Subway,” after- wards called the “ City and South London Railway.” This line, commenced in October, 1886, and opened in November, 1890, by H.R.H. the Princeof Wales, possesses no little historicalimportance asthe precursor of a type of electrically-worked underground railways which promises to afford a solution of the problem pre- sented by the increasing congestion of traffic in great centres of commercial life. It has been described by its Author so recently that a reference to his Paper1 will suffice. During the prosecution of this line through some short lengths of water-bearing strata, compressed air was used in the manner proposed by Mr. Peter Barlow in 1867, and the success of the methods employed in it had led the way to other similar enterprises with whichMr. Great- headwas associated. In 1884, andsubsequently, he patented further apparatus for the applicationof water to excavate in front of the shield, and for injecting cement-grout behind the lining of the tunnel, and for disintegrating the materials cut through by the shield. It is not, however, on his merits as an inventor that Mr. Greathead’s reputation stands, but rather on the talent and perseverance he showed in demonstrating the applicabilityof the shield method of tunnelling under conditions previously un- attempted,and in the ability he showed in workingout the various engineering details of a new type of railway, and thus preparing the way fora marvellous extension of the same. In 1888 Mr. Greathead became jointengineer with Sir Douglas Fox for theconstruction of the Liverpool Overhead Railway; and to the experience of electric traction first applied by him in this country on the City and South London line to regular railway traffic, may perhaps be ascribed some of the large measure of success attained by the overhead line at Liverpool, whichwas openedfor traffic inthe spring of 1893. Of other important works with which he wasconcerned as engineer at the time of his death, it may be unfitting to speak at any length; for his decease occurred when thesewere for the most part in the ’ Minutes of Proceeedings Inst.