Elements of surveying and levelling; with descriptions of the instruments and the necessary tables (1870)
Davies, Charles, 1798-1876 · New York and Chicago, A. S. Barnes & Company · leaf 268
ld-book, thus reduced to the form given in Art. 72. Some-times, the first course is assumed as a line of departure, andthe azimuths of the following courses are calculated with refer-ence to it. Modes of connecting with Surface Survey. 77. In order to determine the bearing of the first course,… … ..^^^^^^ FIRST METHOD. A straight-edge, AB, is mounted on two trestles, and fromit are suspended two plumb lines, B and F, as far apart as thebreadth of the shaft will permit. To prevent agitation fromcurrents of air, the bobs are permitted to dip into buckets ofwater, at the bottom of the shaft;…
Surveying
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
