 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
 | Charles Leander Doolittle - Interpolation - 1883 - 666 pages
...following: If a ray of light suffers two successive reflections in the same plane by two plane mirrors, then the angle between the first and last direction of the ray is double the angle of the mirrors. In Fig. 20 let M and m be the two mirrors supposed perpendicular to... | |
 | Peter Smith Michie, Frank Stowell Harlow - Spherical astronomy - 1893 - 244 pages
...instrument and the manner of using it becomes necessary. When a ray of light is reflected successively by two plane mirrors, the angle between the first and last direction of the ray is twice the angle between the mirrors, provided the ray and its two reflections are all in the same plane perpendicular... | |
 | William David Pence, Milo Smith Ketchum - Surveying - 1901 - 272 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...ray is twice the angle of the mirrors. In (b), Fig. -1i, the angles of incidence and rellection are equal, i = r and i1 r', and E = (i + r) — (iL + r')=... | |
 | American School (Chicago, Ill.) - Engineering - 1903 - 390 pages
...the sextant works is this : If a ray of light suffers two successive reflections in the same plane by two plane mirrors, the angle between the first and...direction of the ray is twice the angle of the mirrors. D is set parallel to CX, and mirror C turns with arm B. The angle between SC and S' G is twice the... | |
 | William David Pence, Milo Smith Ketchum - Surveying - 1904 - 284 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...of incidence and reflection are equal, i = r and i' = r1, and E = (i + r) — (i' + r') — 2 (r — r') C' = (90° — i') — (90° — r) = (r — r')... | |
 | William David Pence, Milo Smith Ketchum - Surveying - 1904 - 294 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...the angles of incidence and reflection are equal, i = ra:ul il = ri, and E = (i + r) — (ii + ri) - 2 (r— ri) C'= (90°— ii) — (90° — r) —... | |
 | Howard Chapin Ives, Harold Ezra Hilts - Surveying - 1906 - 158 pages
...permanent objects or to close the horizon, using range-poles with varicolored flags as sights. 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. Set six range-poles about a... | |
 | Harold Ezra Hilts - Surveying - 1906 - 166 pages
...permanent objects or to close the horizon, using range-poles with varicolored flays as sights. 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. Set six range-poles about a... | |
 | American School (Chicago, Ill.) - Engineering - 1906 - 550 pages
...the sextant works is this : If a rav of light suffers two successive reflections in the same plane by two plane mirrors, the angle between the first and...direction of the ray is twice the angle of the mirrors. D is set parallel to CX, and mirror C turns with arm B. The angle between SC and S' G is twice the... | |
 | Electrical engineering - 1906 - 680 pages
...tho sextant works is this : If a ray of light suffers two successive reflections in the same plane by two plane mirrors, the angle between the first and last direction of tho ray is twice the angle of the mirrors. D is set parallel to CX, and mirror I' turns with arm B.... | |
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