68 



BULLETIN 119, U. S. NATIONAL MUSEUM. 



Perseverance," made by T. Burstall ; and the " Cyclopede," made 

 by T. S. Brandreth. Trials were conducted at Rainhill, near Liver- 

 pool, on a level piece of the line 1 J miles in length, of which 220 yards 

 at each end were allowed for starting and stopping. The competing 

 engines were required to make ten double trips, going over the cen- 

 tral 1^ miles at full speed, which was to represent a journey from 

 Manchester to Liverpool, Then a fresh supply of water and fuel 

 could be taken up and the second ten trips performed, which rep- 

 resented the return journey. The average speed throughout had to 

 be no less than 10 miles an hour. " The Rocket " was the onl}- en- 



no. ^9. STEPHENSON " ROCKET," 182il. 



gine to complete the journeys and fulfill all the conditions, and was, 

 therefore, awarded the prize. She weighed 4^ tons and drew a load 

 of 12f tons. She completed the whole of the double journey at an 

 average speed over the central portion of the track of 13.8 miles an 

 hour, her maximum speed for one trip being 24,1 miles an hour. 



The engine ran on four wheels and had two cylinders 8 inches in diameter 

 by 17 inches stroke placed at the rear end of the boiler and inclined downward 

 at 37 degrees with the horizontal ; the piston rods drove the front wheels, which 

 were 56.6 inches in diameter, thus giving a tractive factor of 19.4. The trailing 

 wheels were 34 inches in diameter and the wheel base 7.17 feet. The cylinders 

 were mounted on iron plates which were bolted to the boiler shell and sup- 

 ported by stays ; these plates also carried the guide bars, which were of square 

 section set diagonally, while the erossheads were of brass, in halves, bolted 

 together and embracing the bars. The steam chests were below the cylinders 

 and the slide valves were driven through an intermediate shaft and levers by 



