140 TRANSACTIONS OF THE [fEB. 1, 



with Trevitliick's locomotives, commenced a series of tests with 

 Mr. Hedley to ascertain the amount of adliesion that could be 

 obtained per ton weight of locomotive, and the amount of trac- 

 tion required to draw the trains. They discarded the empiricism 

 of the day, and found the locomotive would'have sufficient adlie- 

 sion to draw the trains without tlic use of rack rails or ropes. 

 They brought out the famous "Puffing Billy," which is claimed 

 to be the oldest locomotive that did actual service. 



It began to draw coal in 1813 and continued in use until 18G'^, 

 when it was purchased to be preserved in the South Kensington 

 Museum, London. Mr. W. AV. Evans, who had visited the 

 museum several times to see it, says " the wooden frame was only 

 brought to size where attachments were to be made.'' It had 

 tAvo cylinders and grassl)0])pcr beams. The boiler was lagged; 

 the ends put 07i instead of in; the flanges projecting upwards. 

 The cylinders have tJie appearance of being double, the outside 

 one being of boiler iron. It had a crank shaft with which con- 

 nections were made from the beams, giving it motion, thence by 

 gear wheels to the driving axles. Tiie fire door was at tiie same 

 end as the smoke-stack, which was next to the tender; the axles 

 were square. The wheels under the engine are doubtless of 

 more recent construction, as they are of i)resent forms. The 

 rails beneath the engine are similar to those first used. 



The question of transportation and railways was being agitated 

 in this country, and in 1812, Col. John Stevens published his 

 pamphlet on railways, his general ideas being quite similar, it is 

 said, to those of to-day. He stated, "a velocity of 50 miles per 

 hour could be obtained, but a speed of 20 to 30 miles would be 

 more convenient." 



In 1814, Mr. George Stephenson constructed his first locomo- 

 tive, which was geared. It would draw thirty tons at a speed of 

 4 miles per hour. It had two cylinders, each 8x24 inches; a 

 boiler 8 ft. long and 34 inches in diameter, having one internal 

 flue of 20 inches. The speed of the locomotive was limited by 

 its low capacity for generating steam. The cog-wheels gave a 

 great deal of trouble, and in the next year, Stephenson & Dodd 

 took out a patent for direct connections of the cylinders and 

 Avheels, and also for coupling the latter with connecting rods. 

 The engine was carried upon air or steam cushions, which was a 

 great improvement. Springs were afterward substituted for the 

 cushions. 



Though the road bed and rails were being improved, it was not 

 deemed practicable to operate the railways by steam power. 



The construction of the Iletton Coal Eailway, of eight miles, 

 was Stephenson's first important work. 'J'he level jjarts were 

 operated by locomotives, and the inclined planes by stationary 



