86 



MATHEMATICAL AND PHYSICAL SCIENCE. 



[Diss. VI. 



possible way diminish the vibrations and strains to 

 which it was subject, and which would otherwise ra- 

 pidly wear out the machinery. For this purpose he 

 proposed to connect the engine with its carriage by 

 means of steam acting on six pistons in lieu of springs. 

 But perhaps his most material improvement con- 

 sisted in the very simple one of throwing the waste 

 The steam- high-pressure steam as a blast into the chimney, 

 blast. which was found to increase enormously the force of 

 the fire, and the evaporating power of the boiler. 

 Engines having this improvement, and with two ver- 

 tical cylinders, as constructed in 1818, are, or were 

 lately (1854), still atwork on the Killingworth railway 

 dragging coals at the rate of five or six miles an hour. 

 (397.) One of Stephenson's clear practical opinions was 

 Rejects the this, that the locomotive and the railway are part 

 iteam-car- Q f Qne m^chanis^ an( j must be adapted to one an- 

 roads. other. He was not a friend to steam-carriages on 



common roads, and the event proved his sagacity. 

 (398.) If the idea of a locomotive belongs to no one man, 

 Origin of still less does that of a railway, which being one of 

 railways. ^ e mos t elementary of mechanical contrivances, 

 may be traced, under some modifications, almost inde- 

 finitely backwards, as a means of conveying heavy 

 loads with facility. Hence it was at first confined 

 chiefly to quarries and collieries, especially in under- 

 ground passages or drifts. The gauge of these sub- 

 terranean railways, or tram ways, was only about 18 

 inches. The material of the rails was first wood, then 

 cast iron, finally wrought iron, as being less liable 

 to wear and to accident. The wrought iron rail, 

 though not absolutely new, was first generally intro- 

 duced in 1820. About the same time, or rather 

 sooner, the rails began to be made plain, that is, 

 without any vertical guide or flange to prevent the 

 wheels of the carriages from leaving the rail, and the 

 flange was transferred to the wheels of the locomo- 

 tive. Even this was not new, for it had been used 

 by Jessop in 1789. The weight of the rails has 

 been constantly on the increase. The original cast- 

 iron rails weighed only 15 Ib. a yard ; the malleable- 

 iron rail in 1821 weighed about 28 Ib., then 35, 

 afterwards 64, and now rails of 80 Ib. a yard are 

 generally used. 



(399.) One of Stephenson's first cares was to make his 

 Stephenson railways solid and level, and to prevent jerks at the 

 thereto the j unc ^ on ^ the rails. The gauge he adopted, or the 

 locomotive. interval between the rails (now generally used, except 

 on the Great Western Railway and its branches), was 

 4 ft. 8| inches, and was derived from the accidental 

 width of the parent railways in Northumberland. 

 Like Watt and all other innovators, his great diffi- 

 culty was to get the machinery of his locomotives pro- 

 perly made, and the great railway movement of 1825 

 was anticipated by the establishment in 1820 of 

 an engine factory at Newcastle, which, till after the 



opening of the Liverpool and Man Chester Railway in 

 1831, remained the only one, and for long afterwards 

 the best of its class. The cranked axle contrived by 

 Trevithick, and abandoned because it could not be 

 properly welded, was now restored ; the heavy loco- 

 motive was placed on strong hut easy steel springs, 

 wrought iron was skilfully introduced into the wheels 

 of the carriages, and the whole machinery was made 

 to work with precision, and to combine a degree of 

 resistance never before anticipated with comparative 

 lightness. The factory was established in 1821, and 

 the first passenger locomotive was started on the Dar- 

 lington and Stockton Railway in 1825. 



I ought, perhaps, to apologize for these details, (400.) 

 but they illustrate so well the exceedingly gradual 

 progress of mechanical invention, that I have thought 

 them worthy of mention here. 1 The subsequent his- 

 tory of the locomotive and the railway is more gene- 

 rally known. From the date of 1825, both grew and 

 flourished ; the railway first and most steadily ; the 

 locomotive was introduced more cautiously, and met 

 with much opposition ; its triumph was almost en- 

 tirely due to the steadiness of George Stephenson. 



The year 1825, so fertile in speculation, produced (401.) 

 a series of projects for railways to an extent not com- Railway 

 rnonly known, since few of them came into existence^ g u o *" 

 or were even commenced for many years later. Thei825. 

 projected capital of these companies amounted to not 

 less than L.30,000,000 or L.40,000,000. But the 

 only considerable undertaking which was at that time 

 seriously supported was the railway from Liverpool 

 to Manchester, and on that battle-field were foughfc 

 the great questions of the superiority of railways to 

 common roads, of high to low velocities of trans- 

 port, and of locomotives to fixed engines. 



On these three important points, George Stephenson (402.) 

 was in advance both of the science and of the prac- Supenoi 

 tice of his age; and, accordingly, backed chiefly by to common 

 commercial men, who had entire confidence in his roads, 

 sagacity, he had to maintain the conflict almost single- 

 handed against general and professional prejudice. 

 With respect to the Railway, he had long decided in 

 his own mind against the use of steam- carriages on 

 common roads. This conclusion was scientifically 

 based on his own experiments on the friction of wag- 

 gons on railways made in conjunction with Mr Ni- 

 cholas Wood, civil engineer at Newcastle, as far back 

 as the years 1815 and 1816. A simple dynamometer Stephen- 

 of Stephenson's invention was used, and by means of s ? n ' 8 expe- 

 it the two fundamental propositions were established, [ h fic t ^J 

 that the friction is directly as the pressure, and that it f trains, 

 is quite independent of velocity (at leastwhen the speed 

 was moderate). It may be said that these proposi- 

 tions were already known ; but, besides that probably 

 Stephenson and Wood were equally unacquainted 

 with the writings of Coulomb, they could not have 



1 I have found many curious details of the early history of railways in a series of articles on the life of George Stephenson 

 in the Civil Engineer Journal for 1848 and 1849. I am indebted to Mr Robert Stephenson, M.P., for many interesting parti- 



culars respecting his father's inventions. 



