 | Charles Davies - Navigation - 1852 - 412 pages
...spider's line, the horizontal limb is firmly clamped, and the telescope brought down to the horizon ; a light, seen #' through a small aperture in a board, and held at some distance by an assistant, is then moved according to signals, until it is covered by the intersection of the spider's lines. A picket... | |
 | Charles Davies - Navigation - 1854 - 446 pages
...spider's line, the horizontal limb is firmly clamped, and the telescope brought down to the horizon ; a light, seen * through a small aperture in a board, and held at some distance by an assistant, is then moved according to signals, until it is covered by the intersection of the spider's lines. A picket... | |
 | Sir J Butler Williams - Surveying - 1855 - 306 pages
...the quadrilateral. The vertical position r /^~---i -••' can be ascertained by means of a «' I plummet. To see the cross wires in the field of the...signals, until it is bisected by the wires. A picket * This method would be quite correct, if the sun moved constantly hi the same parallel, but the change... | |
 | Charles Davies - Navigation - 1857 - 424 pages
...spider's line, the horizontal limb is firmly clamped, and the telescope brought down to the horizon ; a light, seen *' through a small aperture in a board, and held at some distance by an as- ° sistant, is then moved according to signals, until it is covered by the intersection of the... | |
 | J. H. Hawes - Public lands - 1868 - 252 pages
...spider's line, the horizontal limb is firmly clamped, aud the telescope brought down to the horizon ; a light, seen through a small aperture in a board, and held at some distance by an assistant, is then moved according to signals, until it is covered by the intersection of the spider's lines. A picket... | |
 | INSTRUCTIONS TO THE SURVEYORS GENERAL OF PUBLIC LANDS OF THE UNITED STATES. - 1871 - 106 pages
...spider's line, the horizontal limb is firmly clamped, and the telescope brought down to the horizon ; a light, seen through a small aperture in a board, and held at some distance by an assistant, is then moved adcordiug to signals, until it is covered by the intersection of the spider's lines. A picket... | |
 | J. H. Hawes - Public lands - 1873 - 234 pages
...spider's line, the horizontal limb is firmly clamped, and the telescope brought down to the horizon ; a light, seen through a small aperture in a board, and held at some distance by an assistant, is then moved according to signals, until it is covered by the intersection of the spider's lines. j4... | |
 | United States. General Land Office - Public lands - 1881 - 138 pages
...the horizontal limb is firmly clamped and the telescope brought down to the horizon; a light, s ¿en through a small aperture in a board, and held at some distance by an assistant, is then moved according to signals, until it is covered by the intersection of the spider's lines. A picket... | |
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When the plumb-line, the star Alioth, and the north star, fall on the .vertical spider's line, the horizontal limb is firmly clamped, and the telescope brought down to the horizon ; a light, seen #' through a small aperture in a board, and held at some... 