Note 8 — SECTION IV. EQUAL MILEAGE RATES.
Reading edition
If an engine and tender weighing together 56 tons is capable of drawing a maximum load of say forty loaded wagons weighing 560 tons at 25 miles per hour on the level, it will only take the following loads over the gradients named below, and, in addition to the reduction in the load, the speed would also be considerably reduced.
Level. 40 wagons weighing 560 tons.
Incline 1 in 100 20 ” ” 280 ”
” 1 ” 50 10 ” ” 140 ”
” 1 ” 30 6 ” ” 84 ”
See also Spon’s Dictionary of Engineering; Encyclopedia Britannica “Railways,” and the elaborate work Des Pentes Economiques en Chemins, par M. Charles de Freycinet.