ON RAIL-ROADS.

22?

—t— 42

Then G = 9010 X 12 X ——t = 1434 lbs. the gravity of the

oiOd

load ;

and F = 42 X 12 = 504lbs. friction of the carriages;also $ by Experiment XXII, = 181 H>s. resistance of the rope;WS

and — 651bs. force required to cause the load to de-scribe the length of the pla>ne is the time t = 570 seconds,supposing it free from friction.

Then 1434 + 504 + 181 +65 = 2184 lbs. the resistance,which, in the experiment, was moved through 3165 feet;therefore 2184 X 3165 = 6912360 lbs. the total resistancemoved 1 foot,

Whence

(23067576 power of engine,\ 6912360 effect produced;

Which makes the effective power of the en-gine equal to 30 per cent, of the pressure ofthe steam upou the piston.

Velocity of piston 234 feet per minute,

-carriages 333 feet per minute, or 3.78

miles per hour.

EXPERIMENT XXVI'.

High-pressure steam-engine, cylinder J6>inches, pressure of steam in the boiler 301bs.per square inch, length of plane 2892 feet,height 57 feet 7 inches, being the same asExperiment XXI; rope also the same, 5 inchescircumference.

Time of drawing 8 loaded carriages up theplane, each weighing 8624lbs,, 390 seconds;

p 2