78 HOW TO SEE WITH THE MICKOSCOPE. 



The stage K, upon which the object is placed, has 

 two springs LL, the pins attached to which may be in- 

 serted in any of the four holes on the stage, and by 

 their pressure, which can be varied, they will hold the 

 object under them, or allow it to be moved about with 

 the greatest accuracy. 



The mirror M, besides swinging in the rotating semi- 

 circle N, attached to a bar O, with a joint at each end, 

 allowing a lateral movement, so as to throw oblique 

 light on the object, and for this purpose the tube 

 beneath the stage, carrying the diaphragms, has semi- 

 circular openings cut on either side, leaving a clear and 

 thin stage, allowing the utmost obliquity of illumina- 

 tion. This tube also carries the polariscope, etc. 



The diaphragm P slides in the sub-stage fitting, and 

 consists of a tube containir.g two caps furnishing two 

 sizes of openings, immediately in contact with the 

 under surface of the slide to be examined, and also 

 completely cutting off all light from the mirror, when 

 opaque objects are to be viewed. 



The instrument packs, without being taken to pieces, 

 in a small and neat case, is very convenient for travel- 

 ing purposes, and entirely adequate for very many pur- 

 poses. The general workmanship seems in keeping 

 with the reputation of its makers, while its cost places 

 it within the reach of all. At an advanced cost, it can 

 be supplied with all the usual accessories. 



Last, but not least, I now have the pleasure of pre- 

 senting to my readers 



