The theory and practice of surveying. Designed for the use of surveyors and engineers generally, but especially for the use of students in engineering (1886)
Johnson, J. B. (John Butler), 1850-1902 · New York, J. Wiley & sons · leaf 470
ommon instrument tripod will seldom befound satisfactory for good work. Sometimes extra heavy andstable tripods of the ordinary pattern have given excellent re-sults. 335. Targets.—The requisites of a good target are that itshall be clearly visible against all backgrounds, readily bisected,… … Fig. It is not easy always to fulfil these conditions satisfactorily.To make it visible against light or dark backgrounds, it is well
Surveying
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
