APPENDIX. 845 



APPENDIX. 



RECENT ADDITIONS TO THE MICROSCOPE AND MICROSCOPIC 

 TECHNOLOGY. 



OPTICIANS and microscopists strive continually after 

 absolute perfection in their instrumental means of re- 

 search, so that every little while some new piece of ap- 

 paratus or new method is announced. The most impor- 

 tant recent additions are named here. 



IMPROVEMENTS IN MECHANISM. 



Some notable improvements have been added to first- 

 class instruments. Zentmayer's "Centennial" model has 

 a peculiarly swinging mirror and sub-stage. The mirror- 

 bar is pivoted in the plane of the object on the stage, so 

 that illuminating appliances in the sub-stage may be 

 effected at every angle of inclination, and may even be 

 brought above the stage as a condenser for opaque objects. 

 Mr. Bullock, of Chicago, has also adopted a similar plan 

 in his first-class instruments, and the Bausch & Lomb 

 Optical Company, of Rochester, New York, place a swing- 

 ing-bar below the glass stage of their "Professional" 

 stand, which instrument has many excellent qualities, 

 although it does not reach the idea proposed by Zent- 

 mayer. 



The latter optician has also adopted this mechanism in 

 a cheaper form for students in his "Histological Micro- 

 scope." The "Physician's Microscopes," of the Bausch 

 & Lomb Company, are also models of cheapness and ex- 

 cellence. Beck's "National" microscopes are among the 

 best educational stands. 



