92 HOW TO SEE WITH THE MICROSCOPE. 



that the large and expensive stands are not at all neces- 

 sary; the smaller and cheaper stands, if due care be 

 taken in the selection, will do any practically all work 

 required in the progress of scientific investigation. 

 Furthermore, keep constantly in mind the fact that a 

 great deal of work, legitimately in the line of investi- 

 gation, can only be conveniently accomplished with the 

 small stands. 



Where expense is no object, or even when one can 

 afford two stands without feeling thua crippled in other 

 directions, it will be found a luxury to have the two. 

 In the very nature of things, it is impossible to obtain 

 the firmness and solidity of a large and heavy instru- 

 ment through the medium of the smaller stands, and 

 occasionally this stabilit}' is a real convenience, resulting 

 in a saving of time and labor, as, for instance, in draw- 

 ing with the camera lucida. The graduated revolving 

 platform for the measurement of angles of aperture, 

 and similarly the circular graduated stage, with its 

 centring adjustments, are handy things to have in the 

 house, but cost money, and, as a rule, can be dispensed 

 with. 



And last in this matter, far from being least should 

 the res angusta domi pinch so bitterly as to compel you 

 for the time being to omit some necessary investment, 

 then I say, by all means make sure of the necessary ob- 

 ject glasses, quantity and quality included, and let the 

 stand " sweat" until the "good time coming" shall 

 enable you to provide a new and superior instrument. 

 Remember, too, that the finest and most expensive 

 stand extant, fitted to a poor objective, becomes not 

 only a dangerous tool, but also a positive nuisance. 



