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IOWA ACADEMY OF SCIENCE Voi.. XXVIII, 1921 
Fig. 8 Mounting for the optical pyrometer lamp which permits of horizontal and 
vertical adjustment by the observer while he is looking at the filament through the 
telescope. 
possible to rotate the lamp about the optical axis of the pyrometer ; 
with this motion the filament may be set at any angle with the 
background-image. Vertical motion of the lamp is obtained by 
