A treatise on surveying, comprising the theory and the practice ; (1887)
Gillespie, W. M. (William Mitchell), 1816-1868, Staley, Cady, 1840- [from old catalog] ed · New York, D. Appleton and company · leaf 38
DRAWING TEE MAP. 23 Fig. 19. … square, an instrument very valuable for many other purposes. It is nothing but a ruler let into a thicker piece of wood, very truly at right angles to it. For this use of it, one side of the cross-piece must be even or flush with the ruler. To use it, lay it on the paper so that one edge of the…
Surveying
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
