( 10 )." 



GBEATLT EEDTTCED FBICES 



OF 



OBJECT-GLASSES MANUFACTURED BY 



R. & J. BECK, 



68, CORNHILL, LONDON, E.G. 



ECONOMIC ACHROMATIC OBJECT-GLASSES, 



Applicable to all Instruments made with the Universal Screw. 



No. 



150 

 151 

 152 

 153 

 154 

 155 

 156 

 157 



Focal length. 



3 inches 

 2 inches 

 1 inch . 

 J inch . , 

 J inch . , 

 ^ inch . , 

 i inch . , 

 ^imm. 



Angle 



of 

 aper- 

 ture, 

 about 



18 



38 



80 



no 



no 



180 



Price. 



3 10 

 6 



Magnifying-power, 



with 6-iuch body and 



eye-pieces. 



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



46 

 90 

 170 

 250 

 350 

 654 



15 



23 

 61 

 116 

 220 

 330 

 450 

 844 



27 



41 



106 



205 



415 



630 



800 



1500 



Bevised Catalogue sent on application to 

 R. & J. BECIi, OS, Cornhill. 



