A treatise on levelling, topography, and higher surveying (1876)
Gillespie, W. M. (William Mitchell), 1816-1868, Staley, Cady, b. 1840, ed · New York, D. Appleton and company · leaf 89
9ot [i+i (r^)V-90°)i- f17-] (6° — 90°) is to be reduced to seconds. It is equal to theangle of depression at B; n is the coefficient of refraction. Itis taken at 0.08. 70 LEVELLING, TOPOGRAPHY, AND HIGHER SURVEYING. CHAPTER III. COMPOUND ANGULAR LEVELLING The following problems may mostly be… … (110.) By Angular Co-ordinates in one Plane. Take two sta-tions, A and D, in the same vertical plane with B. At Aobserve the angles of elevation of B and D. Measure A D.At D observe augle ADB. Then, in triangle A B D we getA B, and in triangle B A C we get B C. bc = ad; sin. BDA.sin.BAC sin. A B D…
Surveying
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
