110 HOW TO SEE WITH THE MICROSCOPE. 



powers, than could be possible with the merest speck 

 of glass forming the fronts of the one-fiftieth. 



Whether the ideas thus advanced were correct or not, 

 the fact is patent that in less than two years from the 

 -date of the said letter, Mr. Tolles produced a one-sixth, 

 that excelled for any and all work the performance of 

 any one-fiftieth on record. This one-sixth is still in 

 the possession of the author, who, ere the glass was 

 thirty days old, pitted it against the finest fiftieth to be 

 found in the country. The battle waged for an entire 

 week, but the result was decisive. It was David vs. 

 Goliath, and David had the best of it. 



Scarcely had another month elapsed before Mr. Tolles 

 again sent the writer another glass this time a tenth 

 which, in turn, eclipsed the previous inimitable work 

 of the sixth; while at a still later day, Mr. Herbert 

 Spencer produces a tenth, made on a somewhat differ- 

 ent formula, the performance of which is not excelled 

 by any glass yet made, " be it a fifth or a fiftieth." 



Without reference to the " impossible 180," it may 

 be positively claimed .that either of three glasses named 

 have greater aperture than is possible (or has thus far 

 been possible) to obtain with the fiftieths. 



As has already been stated in the introduction, the 

 writer was the first to call public attention to the claims 

 of American objectives of medium power. Statements 

 so radically at war with the generally accepted popular 

 belief were destined, as a matter of course, to meet with 

 opposition. Microscopists from almost every section 

 came in person to see for themselves, many of them 



