228

MOTIVE POWER EMPLOYED

the engine making 400 single strokes, 5 feet6 inches each.

Then 16 2 X .7854= 201 area of piston, which, multipliedby 50 lbs., the elasticity of the steam, is 10050 lbs., thepressure of the steam upon the piston, which, in the expe-riment, was moved through 400 X 5.5 = 2200 feet.

Therefore, 10050 X 2200=: 22110000 lbs. moved 1 foot,the power of the engine.

_ goi

And G = 8624X 8 X -- = 1373lbs.

34704

Also F = 40 X 8 = 320 lbs.; and, by Experiment XXI,

<p = 273 lbs.

Also —pp =81 lbs. the weight necessary to overcome thevis inertia.

Then 1373 + 320 + 273 + 81 = 2047 lbs. the total resist-ance, which, in the experiment, was moved through 2892feet; therefore, 2047 X 2892 = 59199241bs. moved 1 foot,the resistance.

Whmce ^22110000 the power of the engine,(5919924 the effect produced.

From which we find the effective powerequal to 2b . 7 per cent, of the pressure uponthe piston.

Velocity of piston 338 feet per minute,

- load 445 feet per minute, or 5 miles

an hour.

The same engine was tried with 9 loadedcarriages, which were drawn up in 420 seconds.

The resistance in this case would be G= 1544 lbs.