Lot 247: STEPHENSON (GEORGE)

Letter signed ("Geo. Stephenson"), to his son Robert, discussing the design of their latest railway engine: "I am quite aware that the best tubes are a complicated job to make, but after once in and well done it cannot be any complication in the working of the Engine. This best Tube is a child of your own which you stated to me in a former letter. The interior of a watch looks complicated but when once well fit up, there needs very little more trouble for a hundred years, & I expect the Engine you are fitting up will be something similar to this watch with respect to its working parts"; and reminding him that other parts of their business demand his attention: "We must now push forward to Canterbury as much as possible...It will be necessary for you to be there in the course of a Month and to have your confidential man there...I have not heard any more from the Hetton Company, therefore you will push Scruton forward with his part of the business"; with integral address leaf, postmarked, docketed with contemporary costings or arithmetical calculations, 2 pages, minor dust-staining etc., 4to, Liverpool, 15 April 1828

GEORGE AND ROBERT STEPHENSON WORK ON THE DESIGN OF THEIR LOCOMOTIVE 'THE LANCASHIRE WITCH', precursor to the Rocket and a landmark in steam locomotive development. This is one of the crucial series of letters "between the two Stephensons dealing with the vital question of boiler design" that were consulted by Robert's biographer, Jeaffreson, since when "all trace of the originals has now been lost" (see J.G.H. Warren, A Century of Locomotive Building by Robert Stephenson & Co, 1923, cited by W.O. Skeat, George Stephenson: The Engineer and His Letters, Institute of Mechanical Engineers, 1973, p.111). Hitherto, only the first half-dozen lines of the letter have been quoted, thus omitting George's comparison of his son's boiler design to the interior workings of a watch – a particularly suggestive comparison, in that early designs for British locomotives hid the interior workings so that the engine gave the impression of working as if propelled by its own natural volition, whereas French designed engines tended more to place working parts on full view, often on the exterior.

The engine under discussion is the Liverpool Travelling Engine, now better known under the name given it at the inauguration of the Liverpool & Manchester line on 28 August, the Lancashire Witch. It was specifically designed for this, the world's first modern railway; work on it beginning after Robert's return from South America in 1827. It was intended to replace George's earlier engine, Locomotion No.1, which had been designed more for colliery than passenger use. The next stop on from our engine was to be the Rocket: "It appears that the bent tubes which caused Robert so much trouble in manufacture were not a success, but after modification the engine performed very satisfactorily. The 'Liverpool Travelling Engine' was a definite landmark in steam locomotive development; vertical cylinders were abandoned and the engine was mounted on springs. Although the horizontal disposition of the cylinders (as in the 'Experiment') now gave way to an inclined position, which might be regarded as a retrogression, yet the former side-levers were superseded by direct drive; and the location of cylinders inside the boiler was given up. The twin flues enabled a lighter boiler to be used, with increased hearing surface. An ingenious early attempt to secure expansive working of the steam was also incorporated. After the modifications referred to, a simpler form of return-flue boiler was used, with notable success...The 'Lancashire Witch' was cited by Robert Stephenson as evidence to refute the findings of Walter and Rastrick in favour of stationary engines for the Liverpool and Manchester Railway...The 'Experiment' and the 'Lancashire Witch' were definite landmarks in the escape from the cumbersome beam-engine structures of the earlier locomotives, with the cylinders sunk into the boiler, and each cylinder driving a separate axle. That primitive layout (what else was there to go on?) was not especially ill-suited to Stockton and Darlington conditions, where heavy, slow-moving mineral trains (interspersed with horse-drawn chaldrons or passenger-carriages) formed the traffic...The Stephensons well understood that the Liverpool and Manchester line was to be of quite a different character...From now onwards, their locomotives would have to run at higher speeds than anything previously achieved" (Skeat, op.cit., pp.113-114).