APPENDIX. 345 



three diaphragms, which, when pushed up, will closely 

 reach the object slide, plain and concave mirrors, ar- 

 ranged so that their distance from the object may be 

 varied, 2 eye pieces, A. and C, 2 objectives, 3-4ths inch 

 and l-5th inch, magnifying powers, when the tubes are 

 completely drawn out, from 50 to 375 diameters, eye 

 piece, micrometer and camera lucida, in upright wal- 

 nut case, with lock and key 60 00 



The past twelve-month has witnessed unusual activity on the 

 part of: microscope makers. Mr. Zentmayer, in the production 

 of his " Histological," (as also the advent of the Acme Stand) 

 stimulated other makers to increased energy in the production 

 of small, low-priced and reliable stands capable of performing 

 the work.of larger and costly instruments. 



At the late (August, 1880) meeting of the American Society 

 of Microscopists, held at Detroit, Michigan, two medium-priced 

 stands were exhibited which were regarded bv competent 

 judges as being quite equal to the Acme Stand. One of these 

 was made by Mr. Bullock, of Chicago, and its cost as near as 

 I can learn will be about $50. 



The other stand referred to was exhibited by the Messrs. 

 Bausch & Lomb, of Rochester, N. Y. It is called the tw Inves- 

 tigator." Messrs. B. & L, have furnished the author with the 

 following description of 



THE INVESTIGATOR MICROSCOPE. 



In this stand we confidently claim to have reached a higher 

 degree of perfection than is possessed by any one approximat- 

 ing it in price. We have combined in it the qualities of a 

 first-class and high-priced stand, and at no sacrifice of its 

 working qualities. The different parts are ingeniously com- 

 bined, are strong and firm, and in the parts subject to friction 

 we have introduced, as much as possible, new compensating 

 bearings, which insure the retention of smooth and reliable 

 movements with any amount of work. Working microscopists 

 will understand the value of this quality. When contracted it 

 stands but 11 high, but can be extended to 18 inches. 



