The picture, even when the highest powers are made use of, and the screen is at a distance of twelve feet from the apparatus, is of sufficient clearness and brightness to be available for demonstration to a large audience. For the projection of lantern slides or of large section of tissue following parts of the apparatus are required: Lamp, condenser, cooler and bellows are the same as in the above described apparatus. The stage and objective carrier are swung to one side. The special-projection lens of 300 mm focal distance is to be used. A slide carrier slips into the frame of the bellows, which is sufficiently large to accommodate lantern slides 9×10 and 9×12 cm in size. The slide carrier has a stop at both ends which facilitates its adjustment in the axis of the instrument, and is arranged for the simultaneous reception of two slides, so that while one is being projected it may be charged with a second which may then without delay be pushed into the optical axis as the first is removed. In this way series of pictures may be thrown on the screen without interruption. When so arranged the projection can be made upon a screen 30 feet from the apparatus, over the heads of an audience. Prices: 117. =Projection-lamp= for current of 20 Ampères, with centering arrangement =92.--= =Fixed rheostat= =30.--= (The same, adjustable =$45.--=.) Lamp and rheostat are furnished at factory prices. In ordering it is well to state the strength of the available electric current, also whether it is constant or alternating. =Outfit for projection of lantern slides:= Metal-base with optical bench, triple collecting lens (adjustable) of 150 mm aperture; large cooling cell; slide carrier with bellows; triple revolving arm, with rack and pinion adjustment =108.--= Projection objective of 300 mm focal length =20.--= (A second objective of same focal length may be slipped over the former, the two combined represent an objective of 150 mm focus. Additional price =$20.--=.) =Outfit for microscopical projections:= Cylinder-diaphragm and condenser; objectstage and small cooler with moveable slide-holder. Objective carrier with triple nose-piece: rack and pinion adjustment and micrometer-screw. Broad tube with Iris-diaphragm into which the smaller draw-tube fits. Two projection eye- pieces. Object-stage and objective carrier are provided with hinges. Wooden cover with cloth curtain =84.--= Transport =250.--= -------- Complete outfit =334.--=