OF THE MICROSCOPE. 41 



as follows: Procure a good sound wine cork, and bore two 

 holes through it, the holes being at right angles to each other, 

 and to the axis of the cork. The holes should be of the right 

 size to slide easily, but firmly, on a wire rather more than the 

 sixteenth of an inch in diameter. One piece of such wire is 

 stuck perpendicularly in a wooden foot, and serves as a stand 

 upon which the cork slides up and down ; another piece of wire, 

 having a ring at one end for holding the magnifier, is thrust 

 through the second hole in the cork, and is supported by it in 

 a horizontal position. The horizontal wire should be so long 

 that there will be no danger of injury to the eye or face from 

 the upright wire. A piece of white paper makes the best 

 mirror, as it gives sufficient illumination with low powers, and 

 besides this, it diffuses the light very equally over the object. 

 This, of course, is for use with transparent objects ; when 

 opaque objects are under examination a condensing lens must 

 be employed. 



The Excelsior Microscope. The accompanying en- 

 graving gives a very clear view of this microscope, which is 

 constructed as follows : 



To one end of the lid of a small wooden case or box, is at- 

 tached one of the ends of the box; and when the lid is reversed 

 and turned upside down, it may be slid into the groove which 

 usually receives it, and then forms a stand for the lenses and 

 glass stage, as is shown in engraving. The lenses and stage are 

 supported by a steel rod, D, the lower end of which is hinged 

 to the lid, so that it may be turned down and lie in a groove 

 provided for it. When raised into the position shown in the 

 figure, it is held very securely in place by means of the button, 

 E; and this button also serves to retain it in the groove when 

 it is turned down. The glass stage, G, which is fitted into a 

 frame of hard rubber, slides easily on the stem, D, so as to be 

 readily adjustable for focus, while at the same time it may be 

 firmly fixed, by means of a set-screw, at any desired height, 

 and will then serve as a stage for dissecting purposes. The 

 frame which holds the lenses fits on to the top of the stem. A 

 mirror, H, is fitted into the case, and is readily adjustable by 

 means of the button shown on the outside, so that light may 



