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 288
in line with thegraduated edge, should be only large enough to fit theneedle-point used, so that there would be no^ pl^y- The rulethen turns on an accurate centre, which will not wear. Suchscales, six inches long, could be constructed very cheaply ofGerman silver by any instrument-maker.… … Fig. 66. * Designed by J. A. Ockerson and described in Report of the Miss. RiverCommission for 1885. Manufactured by A. S. Aloe, St. Louis, Mo.17 258 SURVEYING. a needle-pointed pivot at its centre, and having the straightedge graduated so that distances can be measured off eachway from the pivot ;…
Surveying
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