Place point of dividers on scale B upon 100 on horse-power scale and the other upon 500 on the revolution scale. Then carry the space to scale A with lower point on constant 5. Then resting dividers upon upper point open them until lower point is at 40 (diameter). Finally, raise dividers and place lower point at bottom of line. Upper point is now at 9½, indicating the nearest even width 10 as the answer.
A little practice will make one familiar with these rules, and it will be seen that in the belting rules the four motions perform two multiplications and a division.
XVII
SPLICING ROPE
The splicing of a transmission rope is an important matter; the points on which the success of the splice, and incidentally the drive, depend being the length of the splice, which in turn depends upon the diameter of the rope and which is given in the table (Fig. 97a); the diameter of the splice, which should be the same as the diameter of the rope; the securing of the ends of the strands of the splice, which must be so fastened that they will not wear or whip out or cause the overlying strands to wear unduly; and the workmanship of the splice, which should be the best it is possible to secure. When splicing an old and a new piece of rope, the new piece should be thoroughly stretched, for, at best, it is an exceedingly difficult task on account of the stretch and difference in diameter of the rope.
Data Relative to Manila Transmission Rope and Sheaves
| Length of Splice in Feet | |||||||||
| A | B | C | D | E | F | G | H | I | J |
| 1/2 | .25 | .12 | 1750 | 50 | 6 | 20 | 1060 | ||
| 5/8 | .2906 | .16 | 2730 | 80 | 6 | 24 | 970 | ||
| 3/4 | .5625 | .20 | 3950 | 112 | 6 | 8 | 27 | 760 | |
| 7/8 | .7656 | .26 | 5400 | 153 | 6 | 8 | 32 | 650 | |
| 1 | 1. | .34 | 7000 | 200 | 7 | 10 | 14 | 36 | 570 |
| 1 1/8 | 1.2656 | .43 | 8900 | 253 | 7 | 10 | 16 | 40 | 510 |
| 1 1/4 | 1.5625 | .63 | 10,900 | 312 | 7 | 10 | 16 | 45 | 460 |
| 1 1/2 | 2.25 | .77 | 15,700 | 450 | 8 | 12 | 18 | 54 | 380 |
| 1 3/4 | 3.0625 | 1.04 | 21,400 | 612 | 8 | 12 | 18 | 63 | 330 |
| 2 | 4. | 1.36 | 28,000 | 800 | 9 | 14 | 20 | 72 | 290 |
| 2 1/4 | 5.0625 | 1.73 | 35,400 | 1012 | 9 | 14 | 20 | 81 | 255 |
| 2 1/2 | 6.25 | 2.13 | 43,700 | 1250 | 10 | 16 | 22 | 90 | 230 |
Fig. 97a.