706 



SUMMAKY OF CURRENT RESEARCHES RELATING TO 



a sliding-piece actuated by rack-and-pinion. Another sliding-piece is 

 at right angles to this, and carries a cylindrical plug, which in its turn 

 is connected to the toothed cylindrical disc on which the vertical stage 

 stands. This stage is perforated by a rectangular notch with semi- 

 circular ends, arid the object-slide, itself circularly perforated, carries 

 the actual holder, and is operated by a rack-and-pinion. As each of the 

 parts is capable of independent movement, the object-holder cau receive 



Fig. J co. 



at least six different adjustments. The object is set on a small glass 

 tube fitting into a suitable hole in a kind of wheel, and this arrange- 

 ment removes it from the region of shadows. The teeth on the circular 

 base permit of the quadrantal vertical rotation of the object-table.* 

 The apparatus may be used for photography of transparent objects, 

 as in fig. 161. 



* A photograph of Dsedalochila avara has been submitted to us as a specimen 

 of the capabilities of Dr. Wandolleck's arrangement, and it seems very good.— [Ed.] 



