54 
C. Small Stand (Fig. 17). 
This stand is in form and size similar to tlie tripod stand IX. 
Not inclinable. The polariser is mounted together with a con- 
denser of 1.0 aperture in a sleeve and may be rotated about the 
optic axis by means of the lever a. After having drawn the po- 
lariser down Avithin the sleeve a short distance (so as to bring 
the condenser under the underside of the stage), it may be swung 
out of the optic axis by means of the lever h. The polariser may 
also be entirely withdrawn and substituted by the ordinary con- 
denser or a cylinder diaphragm, but none of the special illuminat- 
ing apparatus adaptable to the two stands A and B can be used 
with this stand. 
The large double mirror (plane and concave) is movable 
in all directions and can be easily withdrawn as in the larger 
stands. 
The stage is arranged to rotate and is provided with a 
divided circle. 
The tube is fitted with rack and i)inion adjustment G. This 
mechanism is, however, so carefully fitted that by its means even 
the medium powers (C, D) may be conveniently focussed. The upper 
end of the tube is fitted with a divided circle T for analyser A and 
the lower part with the centering collar c c, Klein's quartz plate 
K and a small shutter to close the aperture occupied by the 
quartz plate when this is not being used. 
With polariser, condenser system, analyser and Klein's quartz 
plate 
Condenser system of 1.0 a})., without polariser, Avith small 
iris diaphragm . 
Cylinder diaphragm 
