210 HOW TO SEE WITH THE MICROSCOPE. 



chase is being gained. In short, it will remain ' a 

 good thing to have in the house " until some genius like 

 Spencer or Tolles shall generally upset all our arrange- 

 ments by some master stroke of advancement. There 

 is no defence possible to provide against such an emer- 

 gency. 



We desire here to say that our remarks as to object- 

 ives also apply as to the purchase of stands. The man 

 who purchases a stand "just for a year or two," as very 

 many have done, and are still doing, does so at a sacrifice 

 of true economy. 



But we have correspondents of another class. Says 

 one, "the inch you name costs $7.00; the one-fourth 

 inch, $20.00, making $27.00; now I can't, for stand and 

 objectives, spend but $45.00, or at the very most, $50.00 ; 

 and then there is a sub-stage arrangement recommended ; 

 also, an extra eye-piece or two. What shall I do? This 

 is all the money I have got, and I have to take the 

 clothes off ni} T back to expend this much." 



Now to all such, and there are many of them, we 

 reply, make a " virtue of necessity " The situation is 

 unfortunate, but, as you say, it cannot be helped. If, 

 by waiting a short time, things can be improved, then 

 you had better postpone your purchase. If to the con- 

 trary, then invest as best you may under the circum- 

 stances. Keep this in mind: Of the two evils, sacrifice 

 the stand rather than the objective ; the latter MUST be 

 maintained up to the standard given. You might pos- 

 sibly substitute, in place of the one-fourth, the best 

 three-tenths obtainable, non-adjustable; but there 



