( 10 ) 



GREATLY REDUCED PRICES 



OF 



OBJECT-GLASSES MANUFACTURED BY 



R- & J. BECK, 



68, CORNHILL, LONDON, E.G. 



ECONOMIC ACHROMATIC OBJECT-GLASSES, 



Applicable to all Instbumksts made with the Universal Scp.ew. 



No. 



150 

 151 

 152 

 153 

 154 

 155 

 156 

 157 



Focal length. 



3 inches 

 2 inches 

 1 inch . 

 ^ inch . 

 I inch . 

 iinch . 

 ■^ inch . 



Angle 



of 

 aper- 

 ture, 

 about 



18 

 38 



80 



TIO 

 110 

 180 



Price. 



3 10 

 6 



Magnifting-power, 



■with 6-inch body and 



eye-pieces. 



12 

 18 

 46 

 90 

 170 

 250 



350 

 654 



No. 1. No. 2. No. 3. 



15 

 23 

 61 

 116 

 220 

 330 

 450 

 844 



27 

 41 

 106 

 205 

 415 

 630 

 800 

 1500 



Xevised Catalogue sent on application to 

 R. Sc J. BECK, OS, Cox-nhill. 



