Problems in Surveying, Railroad Surveying and Geodesy: With an Apendix on the Adjustments of the Engineer's Transit and Level

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J. Wiley & sons, 1906 - Surveying - 136 pages
 

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Page 121 - The adjustment of the Y level consists of the following: I. To bring the axis of the bubble into the same plane as the axis of the telescope so that the bubble will remain in the center even though the telescope is turned slightly in the Y's II. To make the line of collimation parallel to the axis of the bubble, in order that the line of collimation may be horizontal when the bubble is in the center. III. To make the axis of the bubble perpendicular to the vertical axis of the instrument, in order...
Page 120 - See parallax adjustment for transit, p. 347. 2. Telescope Level Vial. To make the axis of the bubble perpendicular to the vertical axis or spindle. (a) Set up level on tripod, rotate about spindle until telescope is over two diagonally opposite leveling screws, and bring bubble to center of tube. (6) Rotate level about spindle 180°, and note whether bubble remains in center of tube. (c) If not, bring the bubble halfway back to the...
Page 6 - After bringing the head of the tripod as nearly level as possible by changing the tripod legs, place the bubble parallel to an opposite pair of leveling screws and bring the bubble to the center, remembering that both thumbs turn out or both in, and that the bubble will go in the direction in which the left thumb moves. When the bubble is in the center, turn through 90 degrees and level over the other set in a similar manner. Care should be taken that the leveling screws do not bind, but they should...
Page 22 - To make the Vernier of the Vertical Circle read Zero when the Line of Sight is Horizontal. — Having made the axis of the telescope-bubble parallel to the line of sight...
Page 30 - ... field, similar to the report on level and transit adjustments. PROBLEM F3. USE OF THE SEXTANT Equipment. Sextant (and several range poles if so directed by the instructor). Problem. To measure the angles between 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 that if a ray of light is reflected successively between two plane mirrors, the angle between the incident and reflected rays is...

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