394 HOW TO SEE WITH THE MICROSCOPE. 



well as my Dunkirk lecture. Allow me to assure you, my dear 

 professor, that although we have been pulling at opposite ends 

 of the rope for some months, the generosity I have experienced 

 at your hands has been vastly in advance of what I could have 

 returned, and has placed me in position to receive any criticism 

 that you might offer with the best possible grace. 



I now propose to jerk my end of the rope in a manner that 

 will make things lively with you ! The fact is, when I get 

 after you with a '* sharp stick " you become unusually brilliant 

 with the jerk responsive I I like it. 



I admit that you are one " who demands accuracy of expres- 

 sion in every branch of science " " that the scientist has no 

 right to say what he does not mean, and he has no right to pre- 

 sume that his readers will understand him if he uses incorrect 

 language." I therefore have placed the above little monograph 

 on elementary astronomy at your service, and in timely season r 

 fearing otherwise you might be led astray by my use of the 

 word u sundown " you will see the point. It's true that Joshua 

 of old commanded the sun and moon to stand still, and the 

 story is found in a book generally admitted to be a classic, but 

 no matter. 



Now, professor, I fear that you do not practice what you 

 preach ; for I read (page 92), " if this question were put to a 

 thorough physicist * * * knowing nothing about 

 balsam or fluid mounts, etc." Isn't there an " impossibility ' r 

 here V A thorough physicist knowing nothing, etc. There's a 

 screw loose somewhere. 



llight on your next line is another jumble. Here is a want of 

 accuracy or what not which is it ? You say " Must the scien- 

 tist be led by the nose," etc. If this expression is accurate, I 

 want you to tell me just how this kind of a thing is accom- 

 plished ; give me the p-r-a-c-t-i-c-a-l details, just as it would be 

 done in the flesh, including the " adopt " and the " teach ' r 

 before an audience, too, without " apology "and the why of 

 it. " It's the right and duty of every man of science to ask this 

 little question whenever it occurs to him." " The scientist has no- 

 nqht to say what he does not mean." Let us have the facts. 



Part Second. 180 C> , plus 180, 180 + 4o. It is true, my dear 



