and then subtracting as before we get the required diameters
| 12 in. | 10.30 in. | 8.17 in. | 6.13 in. | 4 in. |
Example 4. Let the conditions be as in the preceding example, the cone pulley having, however, three steps instead of five, the largest diameter will then equal 8 in.; and by dropping the end differences and subtracting
| 8.00 | = | 2nd | step. | |||||
| Difference of | 2nd | and | 3rd | = | 1.96 | |||
| 6.04 | = | 3rd | „ | |||||
| „ | 3rd | „ | 4th | = | 2.04 | |||
| 4.00 | = | 4th | „ | |||||
we get the diameters 8 in., 6.04, and 4 in., which correspond respectively to 2nd, 3rd, and 4th steps of the table, and to the 1st, 2nd, and 3rd steps of the three-step cone.
Example 5. Let the distance apart of the centres be 60 in., the average difference between the adjacent steps be 21⁄8 in., the smallest step 7 in. and the number of steps = 5. The largest step will then be 7 in. + (4 × 21⁄8) = 151⁄2 inches.
Now an inspection of [Table II.] will show that it contains no horizontal lines corresponding to the average difference 21⁄8 inches, we cannot, therefore, as heretofore, obtain the required differences directly, but must interpolate as follows: since 21⁄8 inches is quarter way between 2 inches and 21⁄2 inches, the numbers corresponding to 21⁄8 inches (for any given distance apart of the centres), will be quarter way between the numbers of the table corresponding to 2 inches and 21⁄2 inches. Thus, in [Table II.], we have under 60 inches,
| and opposite | 2 | 1⁄2 | in.: | 2.40 | 2.47 | 2.53 | 2.60 | ||||
| „ | 2 | 1.93 | 1.98 | 2.02 | 2.07 | ||||||
| .47 | .49 | .51 | .53 | ||||||||
Dividing these differences by 4, we get:
| .12 | .12 | .13 | .13 |