ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



295 



Stein's "Large Photomicroseope."J — Dr. S. T. Stein's instrument 

 (fig. 57) consists of a "parallactic" tripod, to which the camera B is 

 attached by a ball-and-socket joint C. The triple tube D has a ring / 

 connected with E, which has a slot by which it can be moved up and 

 down on a pin in one of the legs of the tripod. The optical part is at F, 

 consisting of an objective e, coarse-adjustment a, fine-adjustment b, and 



Fig. 57. 



condenser d. An arm at c carries a reflector or lamp. The apparatus 

 can be extended so as to give a length of 1^ metres from A to d. 



Photomicrographs of Diatoms. — MM. A. Truan and O. Witt have 

 just issued a work beautifully illustrated by photographs taken from 

 nature of the fossil diatoms from Jeremie, Hayti. Full details of the 

 processes employed are given in the introduction. 



The peculiarity of their method consists in first photographing the 



* Stein's ' Das Licht im Dienste Wiss. Forschung,' 2nd ed. 1885, pp. 177-8 (1 fig.). 



