208

FRICTION OF ROPES.

descent not uniform, with a curve in themiddle, forming part of a circular arc. Num-ber of sheeves 263, weight 9759lbs., ratioof diameter of sheeves to diameter of axle14:1; rope 1200 yards, weight 4468 lbs., cir-cumference 5 inches.

Five loaded carriages, similar to the last ex-periment, each weighing 9408 lbs., descendedagainst 7 empty carriages, each 3472lbs., in360 seconds.

Theorem G =

9408 X 5 X 155444064

= 1659 lbs.

3472 X 7 X 155444064

= 857 lbs.

and

™ ^ 47040 + 24304 X 3672 .

1 = 1059 - i6A x 360- = 1534 lbS -

<p = 1534 — 857 + 215 + 112 = 350 lbs. the resistanceof the rope.

The same number of carriages are usuallyemployed on this plane as on the preceding,which leaves a considerable surplus of gravityto effect their motion upon the plane.

EXPERIMENT XVIII.

Self-acting plane, similar to the two last;length 2706 feet, height 76 feet 5 inches,descent nearly uniform, and line of directionquite straight; weight of wheel 454lbs., ratioof wheel and axle 24 :1, number of sheeves