United States. Weather Bureau, Cloud, W. S, Gregg, Willis Ray, 1880-1938, Jakl, Vincent Edward, 1880-, Lane, Russell Charles, 1893-, Samuels, Leroy Thomas, 1893- · Washington : Govt. print. off. · leaf 81
t set, measure off one-fourth the base plate is level. Check for levels before each of distance between these two points to a point D and adjustments 2, 3, and 4 is attempted. bring the line of sight to this position by moving the The instructions for the adjustment and checking of reticle… … as the result of extended experience with these instru- the incident beam of light, the deflection is no longer at right angles, but may be either greater or less than 90°, ments. The adjustments of the theodolite are such as to cause depending upon the relative position of the prism. (1) the…
Meteorology · Aeronautics in meteorology
Internet Archive · University of Illinois Urbana-Champaign · Public domain (published before 1931). Free to use for anything.
