68 



Franz Schmidt & Haensch. Berlin S. 



lescopes). The slit telescope, which is fitted with a comparison prism, 

 and the scale telescope are fixed upon the stage plate; the observing 

 telescope is made to revolve about its vertical axis. (Fig 1 . 1.) 



Fig. 1. 



b. Medium Size Spectrum Apparatus. 



Mounted upon cast iron tripod stand with brass column and closed 

 prism casing, fitted with 3 telescopes as above. The slit and scale tele- 

 scope are rigidly attached to the prism casing and the observation te- 

 lescope is connected with the latter in such a manner that it may be 



adjusted by rack and pinion coarse and micrometer fine adjustment; any 

 portion of the spectrum may thus be brought into the center of the field. 

 The scale telescope is provided with illuminating flame and the slit 

 telescope is fitted with a comparison prism. The height of the prism is 

 35 mm; the telescope magnifies 10 times. (Fig. 2.) 



