The stage is revolving and graduated on the edge into 360 degrees. A pointer indicates its position. The polarizer has stop at zeropoint and also marks at 90°, 180° and 270°. It is held in a spring-sleeve and the substage can be raised and lowered by lateral screw, or may be swung to one side. The condenser is mounted in separate arm above the polarizer and swings out of the optical axis by means of a lever, if parallel instead of convergent rays are desired. The analyzer fits into an opening of the tube above the objectives and can be instantly thrown in or out of the optical axis. There is a slot below the analyzer for the insertion of quartz and gypsum plates. By means of a collar with two centering screws attached to the end of the tube, the objective may be brought into the optical axis. Price of this microscope with eye-piece I with cross-lines, Klein's quartz wedge and gypsum plate, red, I. order =$56.--= 40. =The same= with eye-piece III. and objectives 3 and 5. Magnifications 60-250 =74.--= =Dissecting Microscopes and Hand Lenses.= [Illustration: Large Dissecting Microscope No. 41.] 41. =Large Dissecting Microscope.= Stand on heavy horse-shoe base, large stage with glass plate, adjustment by rack and pinion. The lens-carrier is movable for examining large plates. Illumination by movable plane mirror and white glass plate. Metal hand- rests covered with leather may be attached to the sides of the stage. They fit inside the mahogany case. A black metal plate with wheel-diaphragm or a milk- glass-plate can be inserted below the stage, serving as dark or white back-ground respectively. Stand without lenses in mahogany case =16.--= 42. =The same= with three aplanatic lenses after Steinheil, magnifying 8, 16 and 20 diameters =28.--= 43. =The same= with these lenses and Abbe's drawing apparatus =40.--= 44. =The same stand= with prism-tube No. 49 for erected image. Objectives 1*, 2, 3, magnifying 18, 40 and 80 diam. =47.25= [Illustration: Simple Dissecting Microscope No. 45.] 45. =Simple Dissecting Microscope=, with adjustment by rack and pinion, movable plane mirror and white glass plate, glass stage in metal frame. Metal hand-rests covered with leather fit inside the case. Stand without lenses =8.--= 46. =The same= with two aplanatic lenses after Steinheil, Magnification 10 and 20 diam. =16.--=