374 SEC2 ION MECHANICS. 



" Puffing Billy," an engine which began work in 1813, and got along 

 without the aid of cogs by mere adhesion upon plain rails ; it is a 

 rude-looking machine, but it laboured up till the date of the last Exhi- 

 bition (1862), doing its work for forty-nine years on the railway belonging 

 to the Wylams Colliery, and as tradition says, interesting George 

 Stephenson, who as a boy saw it in daily operation. 



On the ground floor also we have, 1954, the " Rocket," with which 

 seventeen years after the starting of" Puffing Billy," George Stephenson 

 carried off the prize in the Manchester and Liverpool Railway compe- 

 tition. The leading particulars of this engine are as follows : A pair 

 of 7^ inch cylinders, i' 5" stroke, placed at an inclination, driving 

 4' 6" wheels, the boiler multi-tubular, having twenty-four three and a 

 half inch tubes, while the fire is urged by the waste blast. Before 

 alluding to this I ought to have mentioned that in one of the Blue Books 

 to which I have called your attention, that which gives the evidence 

 before the Commission in the year 1817, there is a statement by a witness 

 that in "those parts there are machines called locomotives," c. &c. 



Once more I am compelled to say that time will not admit of my 

 entering into any detail in respect of the modern locomotive, except to 

 remark that by the aid of excellent boilers, of high pressure (steam 

 140 Ibs. to the inch), of considerable, although rather imperfect ex- 

 pansion, effected by the link motion, there is provided for the use of 

 our railways a machine which in the " Passenger" form is competent to 

 travel with ease and safety sixty miles an hour ; and in the " Goods" form 

 is competent to draw a load of 800 to 1000 tons, and to attain these 

 results with a very commendable economy in fuel. I have put on the 

 wall two diagrams of Locomotives of the convenient form for local 

 traffic that we call Tank engines ; and I have before me No. 1957^, a 

 most beautifully made sectional working model of a Russian six-wheeled 

 " Goods" engine. 



Within the last twenty years another description of steam-engine 

 has acquired a prominent and important place among our Prime- 

 movers ; I allude to the Portable engine, or to the Portable engine in 

 its more complete form of a self-propelling or Traction engine. The 

 general construction of these machines borders closely upon that of 

 the locomotive. Very great attention has been paid to all their details, 

 and the Royal Agricultural Society of England, by their excellent 



