 These adjustments are practically the same as those for the transit. THE SEXTANT. Description. — The sextant consists of an arc of 60°, with each half degree numbered as a whole degree, (a), Fig. 31, combined with mirrors so arranged that angles can...  Surveying Manual ; a Surveying - Page 147by William David Pence - 1915 - 388 pagesFull view - About this book
 | William David Pence, Milo Smith Ketchum - Surveying - 1904 - 282 pages
...(a), Fig. 31, combined with mirrors so arranged that angles can be measured to 120°. Theory. — The principle upon which the sextant is constructed is...successively between two plane mirrors, the angle between the flrst and last direction of the ray is twice the angle of the mirrors. In (b), Fig. 31, the angles... | |
 | William David Pence, Milo Smith Ketchum - Surveying - 1914 - 282 pages
...(a), Fig. 31, combined with mirrors so arranged that angles can be measured to 120°. Theory.. — The principle upon which the sextant is constructed is...mirrors. In (b), Fig. 31, the angles of incidence and reflectiop are equal, i = r and i1 = r1, and E = (i + r) — (i1 + r1) = 2 (r- r1) 0'= (90° — i1)... | |
 | Howard Chapin Ives - Surveying - 1914 - 324 pages
...permanent objects or to close the horizon, using range poles with varicolored flags as Theory. The principle upon which the sextant is constructed is...successively between two plane mirrors, the angle between the incident and reflected rays is double the angle of the mirrors. Method. Either measure the angles at... | |
 | William David Pence, Milo Smith Ketchum - Surveying - 1915 - 418 pages
...31, combined with mirrors so arranged that angles can be measured to 120°. Fig. 31. Theory. — The principle upon which the sextant is constructed is...the ray is twice the angle of the mirrors. In (b), Pig. 31, the angles of incidence and reflection are equal, i = r and i' =r', and E = (i + r)-(i' +... | |
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