23 



We also supply the Combination Lens, No. 1, fitted to a sliding sleeve to 

 which a small stage with spring object-holders is attached. In this form the 

 lens is known under the designation of "The improved Algascope", No. 2. 



If a sliding sleeve of this description be ordered separately, 

 it is necessary to send us the lens combination for adaptation. 



Code- words: 

 Price of the Dissecting Combination Lens, No. 1 . . Marks 40. . Palndato. 



,, ,, ,, improved Algascope, No. 2 48. . Palustre. 



Sliding sleeve with stage, No. 2 a . 8. . Fallar. 



2. Large Dissecting Lens, No. 3, with double objective having collective 

 lenses of 33 mm aperture and a dispersive lens whose distance from the former 

 may be varied. The magnification varies with the position of the dispersive lens 

 within a margin of X 5 to X 10, and the free working distance ranges between 

 70 and 60 mm; see Fig. 43. 



3. Small Dissecting Lens, No. 4, of simpler construction than the prece- 

 ding, magnifying 4 to 5 times. 



The two last -mentioned BRttCKE lenses are specially adapted for Stands 

 L I and L II. 



Aplanatic Lenses, STEINHEIL'S formula, consisting of three cemented lenses 

 (see Fig. 8 and 9) and likewise giving large working distances, are supplied by 

 us in two distinct forms, viz: 



1. Aplanatic Lenses, Nos. 58, Fig. 8, of the earlier type, having only 

 a moderately flat field. Of this type we supply four different lenses, magni- 

 fying from 6 to 30 times. The higher powers are adapted for use with dissecting 

 stands, the lower ones as hand lenses or with a lens holder. 



Fig. 8. 

 Steiuheil Aplanatic Lens, No. 7, with Handle, No. 19 (20 



(Full Size.) 



