1C8 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



Fig. 657 



Fig. 658. Magnifier. 



The common 

 magnifying glass 

 or simplest kind 

 of microscope is 

 nothing but a 

 converging lens 

 of very short 

 focus. This in- 

 strument enables 

 us to see objects 

 which could not 

 possibly be seen 

 by the unassisted 

 sight. The bota- 

 nist detects by 

 means of it the 

 delicate organs 

 of plants, and workmen in every department of the arts use 

 it for minute adjustments and operations. 



(Figs. 657, 658, and 659.) These are variously mounted, 

 most usually having a rim of black horn, turning on a pivot 

 into a box of the same material, and having a slight pro- 

 jection on one side of the rim, to open it conveniently. 

 They are made of three sizes as represented in the cuts 

 Price, 75 cts., 50 cts., and 44 cts. 



