APPENDIX. 409 



MAGNIFYING POWER OF ZEISS'S OBJECTIVES AND OCULARS. 



The lens A* is a particularly useful low-power lens, as by merely rotating 

 a collar, a great variety of magnifying power is obtained without changing 

 the leus. 



MAGNIFYING POWER OF LEITZ'S OBJECTIVES AND OCULARS. 



C. LIST OF MAKERS OF MICROSCOPES, <fcc. 



MICROSCOPES. 

 American Makers and Agents. 



Bausch & Lomb Optical Co., Rochester, N. Y. 



J. W. Queen & Co., 1010 Chestnut Street, Philadelphia. 



Williams, Brown & Earle, N. E. cor. Tenth and Chestnut Sts., Philadelphia 



Eimer & Amend, 205-211 Third Avenue, New York. 



Joseph Zentmayer, 209 S. Eleventh Street, Philadelphia. 



36 



