PROCEEDINGS OF THE POLYTECKNIC ASSOCIATION. 641 



He designed, it appears a much greater pressure, but his experi- 

 ment having to take place between the running of frequent trains, 

 and an injunction was laid upon him, by the proprietors of the 

 track not to exceed 200 lbs. 



"A pedal brake wheel was fixed on the centre of the driving 

 wheel axle, and the brake block adjusted to clear it. The engine 

 carried himself and son, the superintendent of the ways and 

 works, locomotive engineer, and four others, making eight per- 

 sons. She started under the pressure on the brake (unobserved 

 in the hurry till her return) and ran from Stratford to Seabridge 

 and back, a distance of four miles in half an hour. The brake 

 wheel, a rough casting, was polished with the friction. The 

 working pressure was set by the regulator at 20 lbs. on the square 

 inch on the pistons, only 2| inches in diameter. This pressure 

 propelled the engine and its passengers (two tons), with the im- 

 pediment of the brake on, the distance of four miles, at the rate 

 of eight miles per hour. Thus 39 cubic feet, at a density of 11 

 atmospheres, or about 400 feet of atmospheric air, efiected a per- 

 formance which gave entire satisfaction to all who witnessed it. 

 As the chief locomotive superintendent, who was absent during 

 the first experiment, complained that the workmen neglectied 

 their business on account of the interest excited, he was allowed 

 the favor of a second experiment, and the experimental engine 

 was taken out of the way down to Cambridge, where it was filled 

 by the same pumps to the same pressure as before, under the 

 supervision of the superintendent of the locomotive department 

 and the principal foreman of the establishment. Several of the 

 proprietors of the eastern counties went down to Cambridge to 

 witness the performance. The engine started opposite the 60th 

 mile post on the Water Beach Junction. The working pressure 

 was set by the regulator at 15 lbs. only on the square inch, and 

 she ran one mile in five minutes — rate, 12 miles per hour; then 

 at 20 lbs., and she ran the second mile in four minutes — rate 15 

 miles per hour; the regulator was then reduced 1.15 lbs. and she 

 completed a journey of 5| miles in 19 minutes." 



"A steam locomotive loaded with engineers, &c., followed and 

 witnessed this decidedly successful experiment. This small 

 engine," says Mr. Parsey, " would have run twenty miles, if 

 charged to the density I had proposed." 



Mr. Parsey then proceeded to describe the leading features of 

 his invention, consisting chiefly in the regulator used, and by 



[Am. Inst.] 00 



