Cylinder diaphragm with 3 stops of different apertures.
Condenser.
Diaphragm carrier with iris diaphragm.
Plane and concave mirror.
To substitute the condenser for the cylinder diaphragm the diaphragm carrier is turned to the side and the cylinder diaphragm is drawn out of the sleeve which holds it in position and into which the condenser readily fits. The diaphragm carrier is then turned back into position and the amount of light regulated by manipulating the knob controlling the size of the iris. The whole sub-stage may be raised or lowered in the optical axis by means of a rack and pinion, and a similar arrangement permits lateral illumination by moving the iris diaphragm in the horizontal plane.
Ground glass and colored plates may be inserted above the iris diaphragm.
$24.—
c. Illuminating Apparatus for Stand II and IIa (p. [36] & [38]).
The condenser and iris diaphragm form one piece, giving central but no oblique illumination. The whole apparatus may be raised and lowered in the optical axis by means of a screw. The cylinder diaphragm may be inserted in place of the condenser. A ring below the iris diaphragm permits the insertion of glass discs for the purpose of modifying the light.
$12.—
d. Illuminating apparatus for Stand IIb (p. [40]).
The same as for II and IIa fitted in a fixed sleeve; without the side-screw.
$10.—