MICROSCOPES. 225 



The magnifying powers in this microscope are as follow : 

 No. 1, 36 times; No. 2, 64; No. 3, 100; Nos. 1 and 2 

 combined, 169; Nos. 1 and 3, 256; Nos. 2 and 3, 400. 

 Nos. 1, 2, and 3, 676 superficial measure. 



To use this Microscope. -When taken out of the box, fit 

 the stage into the small tube by the pin. Screw the pillar 

 on the top of the box, and the magnifier you intend to use, 

 into the arm D, and it is ready for use. Place the object 

 on the stage ; turn the mirror, M, to reflect the light up- 

 wards through the objects to the eye, at A. This is done 

 best while looking through the magnifier ; now slide the 

 stage up or down, till the object is quite distinct. 



In the examination of opaque objects, the mirror is of no 

 use ; but you must let as much light as possible fall on the 

 surface of the object, and take particular care not to shade it 

 by the head or any part of the dress. There are three mag- 

 nifiers of different foci belonging to the microscope ; the 

 smallest power has the largest aperture. They may be used 

 separately, or either two may be used at a time, or all three, 

 by screwing them one on the other ; by this means you have 

 seven different powers. Price, - So. 00. 



" without mirror, $3.50. 



Description and Manner of Using the Single or Compound 

 Microscope. (Fig. 749, next page.) Screw the pillar A 

 into the box, and the magnifiers, 123, into the arm at the 

 top. The magnifiers are of different powers, any one, two, 

 or the three may be used ; when three are used, the one 

 with the smallest glass should be screwed in first. The 

 body, B, containing the eye glasses may b< screwed on to 

 the magnifiers ; the power of the instrument may be in- 

 creased, by making the body longer with drawing out the 

 head a little. Place the microscope in a position that the 

 light may fall on the mirror, c, and adjust it so that the 

 light may be thrown on the object placed on the stage, D, 

 which slides on the pillar by which the microscope is ad- 

 justed to the proper focus : E, a pair of forceps, which are 

 opened by pressing the studs; any small object may be 

 held by them and fixed to the stage : F, is a plate of ivory 

 which fits in the stage, and is used for opaque objects ; the 

 black side for white objects, and the light side for dark 



