 | United States. Weather Bureau - Atmosphere, Upper - 1921 - 148 pages
...on distant rod, then shift the Fio. 41.— Horizontal axis adjustment. 3. The standard adjustment: To make the horizontal axis of the telescope perpendicular to the vertical axis of the instrument, carefully level the theodolite and sight on some high point, as a steeple S, figure 41, lower the telescope... | |
 | Meteorology - 1928 - 158 pages
...they always give a 90° angle of deflection of the line of sight. 29. (3) The standard adjustment: To make the horizontal axis of the telescope perpendicular to the vertical axis of the instrument, carefully level the theodolite and sight on some high point, as a steeple S, figure 7, lower the telescope... | |
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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. 
