﻿420 



Mr. A. Ferguson on Photographic 

 Fijr. 1. 



A 



\ZZ1 



Condensing Lens 



I USE !i DROt 



CflM en A LENS 



I/imp a Screen 



Watee? Tank 



Fccuss/ng Sc/fEEN. 



The above diagram require^ no comment, save that the 

 water-tank — a glass cell with parallel sides — is used to 

 prevent undue heating of the drop, and that the camera lens 

 used is detached from the bellows of the camera, and fixed 

 on an independent movable stand, thus permitting greater 



magnification. 



Fi-. 2. 



The drop photographed is formed at the end of a siphon- 

 tube standing vertically in a beaker brimful of the liquid 

 employed. The end of the tube should be ground flat, and 

 should be truly circular in section. The beaker itself stands 

 on an adjustable table, by raising or lowering which the 

 pressure in the drop can be varied and the curvature altered 

 accordingly. Beaker, tube, and drop are photographed, and 



