OBJECT GLASSES. 103 



by his two sons, both of them, as a matter of course, 

 N " to the manner born," and in the very prime of life 

 and activity. 



Thus far I have simply referred to Spencer and 

 Tolles, because they have contributed largely to the 

 production of high-angled objectives; but the list of 

 American opticians is not thus complete; we have 

 Wales, Zentmayer, Grundlach, and Grunow yet in 

 reserve, whose productions in their several lines are 

 not inferior to any imported. 



In the foregoing brief and general history of the 

 American wide-angled objective, the conclusion is in- 

 evitable, first, that during the past ten years something 

 has been accomplished, and that in the interim our 

 opticians have not been idle ; secondly, that the modern 

 high angled glass is to be judged of strict!} 7 on its merits, 

 and not by what was affirmed of a medium aperture ten 

 long years ago. 



The converse of this is equally true, and the author, 

 in presenting his views of to-day, declines to be held 

 responsible for what the future may bring forth. 



In this place it may be well to consider what> in 

 common parlance, constitutes a high-angled glass. The 

 writer has already in print stated his individual views 

 which have since undergone no change. As a rule, refer- 

 ence being made to wide apertures, most persons are 

 prepared for some great show of figures, such as "175" 

 or "179"; others might call for nearly "180"; and 

 then again, others there are who would insist on pass- 

 ing the " impossible" 180 corner, and revel among the 



