﻿294 Gaylorcl: Complete Photo -micrographic Apparatus. XVI, 3. 



In iiractice tlie apparatus offers certain advantages over tlie larger 

 foriiis of apparatus which arc dividecl between two tables. 



I) The apparatus once centered may be raoved by means of 

 tlio roUcrs to any poiut desired. 



II) The ai)paratus may be used equally well in the horizontal 

 or vertical position. 



III) The apparatus may be adjusted to any height convenient 

 to the observer without disturbing the alignment. 



IV) The entire apparatus may be centered to an independent 

 souree of light without disarranging the alignment (sunlight etc.). 



V) It takes up less floor space than the larger apparatus. 

 The criticism tliat the caniera and microscope should be entirely 



separate does not hold for this arrangement, and no bad effects 

 from Vibration have been noted. (The apparatus has been in use 

 more than oue year.) The arrangement of the table, sliding support 

 and Camera has been carried out by R. Winkel. 



The tripod foot and the tube illuminating beuch have been 

 constructed after the writers specifications by the Spencer Lens 

 Company, Butfalo N. Y. The entire apparatus may be had from 

 either firm. — The 90^ arc lamp is from A. T. Thompson, 

 Boston, LT. S. A. 



A mechanical adaptation of the method of Illumination recently 

 published by Köhler^ is with the consent of Dr. Köhler being 

 applied to the apparatus. 



Note: The writer has lately had the pleasure of seeing a 

 similar arrangement for elevating the table and an identical arrange- 

 ment of screws aud roUers for the feet, in course of constructiou 

 in the work shops of Zeiss in Jena. As the firm of Zeiss was not 

 aware of my construction, their improvement must be considered as 

 an independent altho later application of the same device. 



^) See this Journ. vol. XVI, 1899, p. 1. 



[Eingegangen am 24. August 1899.] 



