Tables showing difference of level in feet :
corresponding to a given angle when the distance is read in metres or feet, and for horizontal reductions, for use with stadia /
Computed by J.A. Ockerson and Jared Teeple ...

APA Citation

Ockerson, J. Augustus., Teeple, J., United States. Army. Corps of Engineers. (1879). Tables showing difference of level in feet: corresponding to a given angle when the distance is read in metres or feet, and for horizontal reductions, for use with stadia. Washington, D.C.: G.P.O..

MLA Citation

Ockerson, John Augustus, 1849-, Jared Teeple, and United States. Army. Corps of Engineers. Tables Showing Difference of Level In Feet: Corresponding to a Given Angle When the Distance Is Read In Metres Or Feet, And for Horizontal Reductions, for Use With Stadia. Washington, D.C.: G.P.O., 1879.