THEAICRC^COPE 



An llj^^WRATED 



APIraLW^A(5^zI^^E . 



Vol. XII. 



WASHINGTON, D. C, JUNE, 1892. 



No. 6. 



Selecting a Microscope. 



By EDWARD BAUSCH, 



ROCHESTRR, N. Y. 



[From Manipulation of the Microscope^ pp.90 — 98. ] 



When a person has concluded to obtain a microscope, a suita- 

 ble selection is a matter of considerable importance to him. The 

 varieties are innumerable, prices without end, and all sorts of 

 claims are made for them. The variety of special lines of inves- 

 tigation involves nearly as great a variety of requirements. The 

 amount of money to be expended ; what shall be the stand ; what 

 the objectives ; shall the entire outfit be purchased at one time or 

 little by little, are all questions of paramount importance which 

 the writer does not expect to solve, but hopes to give sufficient 

 information that a more intelligent selection may be made than 

 might probably be done otherwise. 



Stands. — Starting out wnth the assumption that there are two 

 classes of instruments to select from, the long and short tube, the 

 first decision to reach will be this point. In a general way it may 

 be said that there are no optical advantages in either, but which- 

 ever is adopted must be retained. 



The principal consideration is whether the instrument is to be 

 used in an upright or inclined position. If the former, the short 

 tube is usually selected, as it can be used comfortably on a table 

 of ordinary height. This one objection which might be and often 

 is raised against the long tube is easily overcome by the friends 

 of the latter providing a suitable table for the same. As the in- 

 strument is used in the upright position only in a few special 

 lines of study, it is really only of weight in this direction, as the 



