142 HOW TO SEE WITH THE MICROSCOPE. 



Thus far, whatever force may attach to the elements of 

 * ' inconvenience " and "bother," of which we have 

 heard so much, I have allowed full play and weight ; 

 but let the reader not lose sight of the fact that those 

 accustomed to the use of adjusting glasses never aban- 

 don them to return to their first love, nor do they re- 

 gard the process of adjusting a superior objective as 

 being in any way or shape a " bother" or " inconven- 

 ience." It may be well, right here, to state a bit of 

 personal experience. I am in the habit of putting ad- 

 justing glasses in the hands of my pupils at the earliest 

 possible moment ; not that they will accomplish more 

 with them for a time than would be the case with those 

 non-adjustable, but in order that the pupil be early 

 brought in contact with them, and thus, by degrees, 

 get accustomed to their use. By adopting this course, 

 the tyro learns, in clue and proper season, an important 

 lesson, to wit, that there are some things to be done 

 besides putting an object at one end of the tube and 

 the eye to the other in order to see what's what. Now, 

 it often happens that there may be more pupils in the 

 laboratory than adjustable objectives, and thus, per- 

 force, a student or two will have to fall back on the 

 non-adjustable. When this state of things occur there 

 is inevitably indications of discontent, and it is never 

 on the part of those pupils occupied with the adjustable 

 objectives. 



So much for the " inconvenience" and " bother." 

 Now, let us get after that other elephant working 

 distance. I have granted that w T ith the higher balsam 



