( h) ) 

 GREATLY REDUCED PRICES 



OF 



OBJECT-GLASSES MANUFACTURED BY 



R, & J. BECK, 



68, CORNHILL, LONDON, E.G. 



ECONOMIC ACHROMATIC OBJECT-GLASSES, 



Applicable to all Instrt;mekt8 made with the Unitersal Screw. 



No. 



150 

 151 

 152 

 153 

 154 

 155 

 156 

 157 



Focal length. 



3 inches 

 2 inches 

 1 inch . 

 ^ inch . 

 J inch . 

 iinch . 



4 inch . 



Angle 



of 

 aper- 

 ture, 

 about 



18 



38 



80 

 no 

 no 

 180 ■ 



Price. 



3 10 

 6 



Magniftino-power, 



with 5-inch body and 



eye-pioces. 



No. 1. No. 2. i No. 3, 



12 



18 



46 



90 



170 



250 



350 

 654 



15 

 23 



61 

 116 

 220 



330 



450 



844 



27 

 41 



106 



205 



415 



630 



800 



1500 



Bervieed Catalogae sent on application to 

 K. & jr. BECIi, Q8, Cornliill. 



