ON RAIL-ROADS.

229

F = 360 lbs.; ij) = 273 lbs. and ^ rz 79 lbs.; which, added

rl‘

together, is 2236 lbs. x 2892 = 6324352 lbs, moved 1 foot.

Whence S22110000 the power,

( 6524352 the effect;and the effective power equal to 30 per cent.

Velocity of piston 314 feet per minute,

-- load 413 feet per minute, or 4.7 miles

an hour.

In this experiment we find a greater ef-fective power produced by applying a heavierload, but the time is diminished in nearly thesame ratio.

The relative effective power is go ^|p er ccn t-

5 338 )

314V eet P er m ' nute

Whence we find the relative performances ( 9024with respect to time and effect (9340

The preceding experiment, shewing theperformance of these two kinds of engines,will form a rule for the practical applicationof similar engines to other planes. Theeffective power of the high-pressure enginesis greater than that of the low pressure, butin these experiments neither exceed 30 percent. The velocity of the pistons was, how-ever, very great, and this would have theeffect of diminishing their performance com-pared with the elasticity of steam in the boiler,otherwise we might have expected a greateramount of effective power. I shall afterwards,