26 THE AMERICAN MONTHLY [Jan 



Our list of foreign correspondents has largely increased 

 and we now have friends all over the world in nearly every 

 nook and corner. We trust our home lists will corres- 

 pondingly increase during- the new year. To all we extend 

 a hearty greeting. 



LETTERS TO THE EDITOR. 



GATES' DOUBLE MICROSCOPE. 



Unless he can make opposite defects in each correct each 

 other I do not see what he can gain. I tried a somewhat 

 similar experiment with the telescope or spyglass in my 

 schoolboy days, but it did uot take me long to find out that 

 meie magnification without a corresponding improvement 

 in definition and resolution was worthless. I think it 

 possible that a double objective might be made so that de- 

 fects of one system might be corrected by the opposite 

 defects of the other, and in this way a much greater work- 

 ing distance be obtained with a greater depth of focus and 

 equal resolution. If my health was better I should try 

 some experiments in this line myself. — Wm. A. Terry. 



Will Report own Work Later. — "I have corresponded 

 with Mr. Gates as to his Double-Microscope. I have 

 thought favorably of it notwithstanding Dr. Stokes' stric- 

 tures, especially as I made some experiments thirty 

 years ago on it. I got a 1-Sth and a l-5th in the eye-piece 

 and a 1-I5th and a l-5th in the eye-piece. That was as high 

 as I could go. I had not higher objectives to try, and only 

 sunlight. The definition was good enough. I intended 

 to publish a paper on the subject — and still intend to do so 

 when I can get the time. But I must submit my paper to 

 both gentlemen. The Journal shall hear from me on it 

 soon." — Arthur M. Edwards, M. D. 



Get Actual Results Properly Certified. — "I am too busy 

 to write an article on Dr. Elmer Gates' tandem micro- 

 scopes. Would it not be much better to get some one 

 right on the ground who knows Dr. Gates and can see his 

 laboratory, etc. I would suggest Dr. Frank Baker. Every 



