On Microscopes in General. 3 



material, like a knife- blade in its handle. Sometimes 

 three lenses are thus arranged, and by using one or 

 more of them at a time, the magnifying power is 

 varied. Of this form was the " magnifying-glass " 

 already alluded to, which the writer found very useful 

 before possessing Ross's Microscope. The Codding- 

 ton lens will be seen represented at woodcut No, 3, 

 among the collector's apparatus its glass shutting up 

 into a neat little cylindrical frame, with a short handle 



No. 1 A Simple Microscope. B. Hand-magnifier. 



to which a chain or string can be attached. This in- 

 strument, and a good little hand-magnifier, like that 

 shown at No. 1, B, will always be found useful ap- 

 pendages to the watch-chain always at hand to 

 examine objects out of doors. The Coddington lens 

 has by far the higher power of the two, but from its 

 requiring to be held very close to objects it cannot 

 always be used to advantage. The rnagnifying-glass 

 becomes a microscope when its lens (or combination 



