MICROSCOPES. 



223 



The Insect Microscope (Fig. 

 74-7.) This instrument consists of 

 two lenses arranged in a tube, on 

 the exterior of which is a screw, 

 cut the whole length, and moving 

 in a brass cap connected with a 

 glass shade, about one and a half 

 inches in diameter and one inch 

 high. By this arrangement the 

 insect can be confined without the 

 light being intercepted, and the 

 focal distance accurately adjusted 

 by means- of the screw. The whole 

 surface of butterflies, moths, beetles, 

 &c., may be viewed without giving 

 them pain or injuring their bril- 

 liancy. This kind of microscope is equally well adapted to 

 the viewing of seeds, crystals, sand, minerals, <fec. 



Price, $1.00; larger, $1.25. 



Description of the Universal Single Pocket Microscope. 

 (Fig. 748, next page.) This microscope is extremely simple 

 in its construction, and easy in its application to all kinds of 

 opaque and transparent objects. It is represented on the 

 cut as ready for use. ABC are three magnifiers, one or 

 more of which may be screwed into the arm, D. S is a flat 

 plate or stage for holding the objects ; it is slid up or down 

 the pillar, N, to adjust the object to the focus of the mag- 

 nifier. M is a mirror for reflecting light through any trans- 

 parent object on the stage. O, a pair of tongs to take up 

 any small object. P is a needle fixed in a handle, for turn- 

 ing about any object on the stage while under examination. 

 Q, a caKfel-hair pencil, for cleaning objects, &c. ; the other 

 end cut pen-fashion for taking up fluids, <kc., and placing 

 them on the stage. T is an insect-box ; small living insects 

 are confined therein, between a flat and a concave glass. 

 H is a concave glass to hold fluids ; it is fitted to the stage. 

 A flat glass fitted to the stage, for laying any transparent 

 objects on, is also sent in the box. I is an ivory plate, one 

 side black, the other white, for laying opaque objects on, 

 likewise fitted to the stage. G is a slip of glass used in ex- 

 amining animalculae and the crystallization of salts. 



