Gradient or clivity, denotes the proportionate ascent or descent of the severalplanes on a rail-road...--H. S. Tanner, 1840, A Description of the Canals and Rail Roads of the United States, p. 249
Gradient or clivity, denotes the proportionate ascent or descent of the several
planes on a rail-road...
--H. S. Tanner, 1840, A Description of the Canals and Rail Roads of the United States, p. 249