ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
77 
MICROSCOPY. 
A. Instruments, Accessories, &c.* 
(1) Stands. 
Pillischer’s International Microscope.— This instrument (fig. 1) 
has the Continental length of tube when the joint B is drawn out ; hence 
the title of “ International.” The pillar worked by the coarse adjust- 
ment E carries the fine adjustment D, and the two adjustments are 
therefore independent. C is a milled rim for pushing the whole tube 
up and down in its sleeve. A notable feature is the device for raising 
and lowering the spring clips, which are screwed to a bar F, thus form- 
ing a framework secured to a vertical slide flanged ; the adjustment 
of the clips is effected by raising or depressing this flange. The stage 
has a thin sliding plate G pierced with three apertures for regulating 
the light, and the substage condenser has an iris and ring for stops. 
The substage can be placed excentrically to the optical axis by means 
of a rack and pinion operated by the milled head H, and can also be 
rotated by means of the milled head J. A pivot K enables the whole 
substage to be swung out of use. 
Barnes’ Horizontal Microscope. — This instrument (fig. 2) is con- 
structed by Messrs. Bausch and Lomb from the designs of Professor 
Barnes of Wisconsin University, and is intended for the direct reading 
of the growth or movements of plant organs, &c. It will also be found 
useful in many other lines where a Microscope is required in a hori- 
zontal position. It consists of a nickelled tube with Society screw. An 
accurate spirit-level is attached, its axis being exactly parallel with the 
axis of the Microscope. Vertical adjustment is quickly effected by 
loosening the clamping ring shown near the top of the stand, permitting 
the Microscope-tube to be raised about 200 mm., or clamped at any 
intermediate point. The final vertical setting of the instrument is 
effected by vertical rack and pinion having movement of 75 mm. The 
base is fitted with three levelling screws for horizontal adjustment. 
The eye-piece is of 1-inch focus, and is furnished with a disc micro- 
meter ruled to tenths of a millimetre across the entire field. 
Improved Excelsior Dissecting Microscope. — This instrument (fig.3), 
sold by Messrs. Bausch and Lomb, consists of a small wooden case 
4 by 2 by 1J in. One end of the case is attached to the lid, which 
serves as a cover for the whole. A steel rod, 3j in. long, is fitted to 
the inside of the box, at one side of it, thus being out of the way of 
the forehead when focussing high- or low-power lenses. Bubber magni- 
fiers of one, two, or three lenses, giving a range of magnifying power 
from 5 to 25 diameters, are arranged for adjustment on this rod. A 
plane mirror 2J by in. is fitted to one end of the box in a groove, 
* This subdivision contains (1) Stands; (2) Eye-pieces and Objectives; (3) Illu- 
minating and other Apparatus; (4) Photomicrography; (5) Microscopical Optic3 
and Manipulation; (6) Miscellaneous. 
