zooLoar and botany, microscopy, etc. 



701 



is 5f X 3^ X 2J in. The Microscope is screwed to a metal plate 

 which turns on a hinge joint at the side of the box. This plate forms 

 the sta^e, and cai'ries a mirror beneath. "When the Microscope is 

 removed and placed in the bos the plate is turned back on the top 

 of it. A rackwork coarse adjustment has since been added. The 

 Microscope can be inclined, as shown in the figure, or used vertically. 

 To prevent overbalancing, the bottom of the box is provided at each 

 end with a flat brass slide, which can be extended 2 in. in front of 

 the box. 



ColUns's Portable Microscope. — The peculiarity of Mr. C. Collins's 

 portable Microscope (fig. 189) is that it is permanently attached to the 



Fig. 139. 



lid of the box, so that no time is lost in screwing it to its support as 

 in other cases. The lid itself is fixed to the box, and has a hinge 

 joint at its lower end by which it can bo inclined. A small clamp- 

 screw acting on the brass support fixes the lid, and with it the body- 

 tube, at any desired degree of inclination. 



To replace it in the box the mirror is pushed up to meet the 

 stage, the b(jdy-tube racked down, and the inclined suj^port with- 

 drawn and allowed to fall iuto the box. The lid is turned a half-circle 

 on a pivot at tlie centre of its lower end, so that tlio Microscope now 

 faces tJie inside of the box, into which it can then be dropped by 

 means of the hinge on the lid. 



Box Microscojje. — The instrument shown in fig. 140 was purchased 

 in Paris, and was ai)parcutly made some twenty-five years ago. Like 

 that of Mr. Collins, the Microscope is fixed to the lid, and when not 



