Problems in Surveying, Railroad Surveying and Geodesy |
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Problems in Surveying, Railroad Surveying and Geodesy: With an Appendix on ... Howard Chapin Ives No preview available - 2015 |
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absolute length adjustment altitude aneroid angular azimuth base-line bring the bubble center line Chromatic Aberration computed contour correction cross-hairs cross-section cross-wires culmination cut or fill declination determined Diff difference in elevation direct Dist distance dumpy level Engineer's transit equal Equipment eyepiece feet field field-book form of notes give given in Problem grade graduation Greenwich mean hatchet horizontal axis index error instrument intersection interval latitude Left-hand Levelman line of collimation measuring the angles method micrometer minutes Note-keeper observation obtained offsets parallel perpendicular placed plane plumb-bobs Polaris position Problem G3 range-poles reading Rear Chainman right ascension right-hand rod-reading Rodman sextant side sidereal sight simple curve sketch slope-stake solar Spherical Aberration stadia Stakeman stakes star steel tape striding-level taken tangent telescope tested theodolite tion transit set transitman triangle triangulation stations triangulation system tripod tube vernier vertical axis vertical circle wire zero
Popular passages
Page 130 - C is necessary. IV. To Make the Vernier of the Vertical Circle read Zero when the Line of Collimation is Horizontal. Having made the axis of the telescope-bubble parallel to the line of collimation, bring the bubble to the center, and if the vernier of the vertical circle is adjustable bring it so that its zero coincides with that on the limb.
Page 21 - ... II. To make the line of collimation revolve in a vertical plane when the telescope is turned on its horizontal axis. III. To make the axis of the telescope bubble parallel to the line of collimation. IV. To make the vernier of the vertical circle read zero when the line of collimation is horizontal.
Page 131 - One-half the error is corrected in this case by raising or lowering one end of the level vial. (In the Y level, made by the large Y nuts.) B. To make the line of collimation parallel to the axis of the bubble. These lines must be compared directly with each other by use of either one of the peg tests (Figs.
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 126 - To make the line of collimation perpendicular to the horizontal axis of the instrument; and (6) to make the horizontal axis of the telescope perpendicular to the vertical axis of the instrument.
Page 126 - Set the instrument up on nearly level ground, at a point O, where a clear sight may be had of a point A, a few hundred feet away, and bring the line of collimation to it. Plunge the telescope, and if the line of collimation is not perpendicular to the horizontal axis of the telescope, it will mark a point B. Revolve the telescope by unclamping the upper motion and sight again on the point A. Plunge the telescope and the line of collimation will now strike the point C. A point D, half-way between...
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 140 - ... 8° 9° 10° 11° / Hor. Diff. Dist. Elev. Hor. Diff. Dist. Elev. Hor. Diff. Diet. Elev. Hor. Diff. Dist. Elev. 0...
Page 138 - Hor. Diff. Hor. Diff. Hor. Diff. Hor. Diff. Dist. Elev. Dist. Elev. Dist. Elev. Dist. Elev. 0...