230 THE AMERICAN MONTHLY [Aug, 



photographs, expressed a desire to look through the ob- 

 jective. Having done so, with a most impressive ges- 

 ture, he said : " I thank you very much for this ; it is 

 the event of my life. I never expected to live to see 

 such an instrument and such workmanship. We do not 

 make them because people will not pay for them." Tollfes' 

 B stand, American oil light, direct, and a two-inch ocu- 

 lar were used on this occasion. 



21. A London maker, of the very highest reputation 

 and character, having witnessed a similar exhibition, 

 expressed less demonstratively his satisfaction, but said 

 that Mr. Tolles was the peer of any maker. He added 

 "I made a one-eightieth inch objective, but it was not 

 good." He would not tell who owned it. It has been 

 verbally reported that photographs have since been 

 taken with it. 



22. This objective shows the value of direct light, es- 

 pecially from a clay wick, which gives 25 per cent more 

 illumination than cotton gives. Used two hundred 

 years ago by microscopists, "direct" light had gone 

 into disuse until about forty-five years ago; Oliver Wen- 

 dell Holmes taught its use to his pupils. He said that 

 W. A. Spencer had also used it in testing objectives in 

 course of construction. I have seen Mr. Tolles often 

 do the same thing in his workshops. Even he did not 

 get the best results with the one-seventy-fifth save by 

 sun-light until the writer used the flat edge of an oil 

 flame condensed " direct " by a one-inch ocular fitted 

 into the sub-stage. This illumination has been entirely 

 satisfactory and reliable. As compared with mirror 

 light, it may be said to be thrice as effective. 



23. The opening for light in the one-seventy-fifth is 

 one-sixty-fourth inch. The amount of illumination 

 shown in the first photograph justifies the above quoted 

 remarks of Sir M. MacKenzie and the approval of all 



