and 20 tons on the Eastern division,
neglecting the assistance required from Susquehanna to Deposite. In the following table are given the actual lengths of the several divisions, and the sum of the products of three lengths both by the relative and a uniform resistance on each.
| Division. | Length. | Miles run by an engine not adapted. | Miles run by an engine adapted. | Difference. | |
|---|---|---|---|---|---|
| Western, | 128 | 128 × 3.04 | 128 × 1.0 | 261.12 | |
| Susquehanna, | 139 | 139 × 1.06 | 139 × 1.0 | 8.35 | |
| Delaware, | 104 | 104 × 1.00 | 104 × 1.0 | 0.00 | |
| Eastern, | 88 | 88 × 4.25 | 88 × 1.0 | 286.00 | |
| Sum of differences, | 555.47 | miles, | |||
that is, the miles run by engines adapted to the work on the several divisions will be 555.47 less than the miles run by engines not adapted. (See Appendix F.)
PENNSYLVANIA CENTRAL RAILROAD.
360. The physical character of this road is as follows:—
| Length. | Max. grades. | |
|---|---|---|
| Philadelphia to Harrisburg, | 106 | 45 |
| Harrisburg to Altoona, | 131 | 21 |
| Altoona to Johnstown, | 48½ | 92 |
| Johnstown to Pittsburgh, | 78½ | 53 |
The value of r will be here
| 45 feet grades, | 19 10 |
| 21 feet grades, | 9 10 |
| 92 feet grades, | 39 10 |
| 53 feet grades, | 25 10 |
Whence the equation,