542 



Telescopes. Interference and Diffraction. 



No. 54 474 



54 474 a. 1:13. 



54488. 1:14. 



Telescopes with heavy Wood Tripod Stands, Fig. 54,474, for setting up on the floor, up-and- 

 down motion by crank, horizontal and vertical hand motion for telescope; with Finder: 



s. d. 



The fine motion listed under (b) renders it possible to set the instrument in a horizontal ami 

 vertical direction, cf. Fig. 54,473. 



54,481. Parallactically Mounted School Telescope after Archenhohl, with achromatic objective 

 54 mm aperture, ocular focussing with rack and pinion, objective cap with aperture 

 (which can be closed) for solar observations, a power 36 terrestrial ocular and a 48 power 



CI. 3406, 6004. 



