82 



TREVITHICK'S TRAM-ENGINE. 



CHAP. VI. 



thing surprising. Trevitliick very probably put the 

 two things together the steam-horse and the iron-way 

 and kept the performance in mind when he pro- 

 ceeded to construct his second or railway locomotive. 

 The idea was not, however, entirely new to him ; for, 

 although his first engine had been constructed with a 

 view to its employment upon common roads, the speci- 

 fication of his patent distinctly alludes to the application 

 of his engine to travelling on railroads. Having been 

 employed at the iron-works of Pen-y-darran, in South 

 Wales, to erect a forge engine for the Company, a con- 

 venient opportunity presented itself, on the completion 

 of this work, for carrying out his design of a loco- 

 motive to haul the minerals along the Pen-y-darran 

 tramway. Such an engine was erected by him in 

 1803, in the blacksmiths' shop at the Company's works, 

 and it was finished and ready for trial before the end 

 of the year. 



The boiler of this second engine was cylindrical in 

 form, flat at the ends, and made of wrought iron. 1 The 

 furnace and flue were inside the boiler, within which 

 the single cylinder, eight inches in diameter and four 

 feet six inches stroke, was placed horizontally. As in 

 the first engine, the motion of the wheels was produced 

 by spur gear, to which was also added a fly-wheel on 

 one side to secure a rotatory motion in the crank at the 

 end of each stroke of the piston in the single cylinder. 

 The waste steam was thrown into the chimney through 

 a tube inserted into it at right angles ; but it will be 

 obvious that this arrangement was not calculated to 

 produce any result in the way of a steam-blast in the 



1 It is not, however, quite clear 

 whether the boiler of this engine was 

 of wrought or cast iron. The state- 

 ment that it was of wrought iron is 

 made on the authority of Rees Jones, 

 who worked at the fitting of the en- 

 gine under Trevithick, and was alive 

 in 1858. But other accounts state 



that the boiler was of cast iron, as 

 that of the next engine built after 

 Trevithick's patent certainly was. We 

 allude to the engine erected by Whin- 

 field of Gateshead, for Mr. Blackett of 

 Wylam, in 1804, after Trevithick's 

 own plans. 



