ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 103 



MICROSCOPY. 



a. Instruments, Accessories, &c* 



(1) Stands. 

 Collins's Aquarium Microscope. — Mr. C. Collins's Aquarium Micro- 

 scope (fig. 1) differs from all other forms in that it is applied to the 

 side of the aquarium itself. This is accomplished by making use of 

 a sucker apparatus. The head of the sucker is shown on the left of 



Fig. 1. 



the drawing, with an indiarubber ring surrounding a central piston. 

 The ring is applied to the glass surface of the aquarium, and the air is 

 exhausted by screwing round the head of the piston seen on the ri»ht. 

 Two turns are sufficient to fasten the sucker securely. The rod to 

 which the support of the body-tube is attached passes through the 

 sucker-arm, and can be clamped at any height desired. 



Golfarelli's Micrometric Microscope for Horologists. — This Micro- 

 scope (fig. 2), made by the " OflScina Galileo " of Florence, after the 

 design of Prof. I. Golfarelli, is intended for the use of clock- and watch- 

 makers, enabling them to ascertain, for instance, that the teeth of chrono- 

 meter and duplex escapement wheels are regularly cut. 



The upper part of the Microscope is screwed to a metal stage 

 5 in. X 4 in., supported on four feet, and having a graduated scale on 

 its front side. In a wide groove in the stage slides a metal plate, with 

 four spring clips to hold the object examined. The clips can be 

 variously applied in fourteen different holes. The plate is moved by a 



* This subdivision contains (1) Stands ; (2) Eye-pieces and Objectives ; (3) Illu- 

 minating and other Apparatus ; (4) Photomicrography ; (5) Microscopical Optics 

 and Manipulation ; (6) Miscellaneous. 



