Construction and Selection of Projection Lanterns. 



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50 728 B. 



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2. Model B, constructed with aluminium housing, for institutions having liberal means at 

 their disposal; otherwise as Model A. This type of projector, which we have constructed now for some 

 years, has met with approval everywhere. It is constructed with automatic regulating Direct or Alter- 

 nating Current arc lamp, with arc light hand regulator and in a form suitable for all kinds of illumi- 

 nation, Fig. 50,728 B. 



3. Projection Apparatus of the Schuckert form, with tilted arc lamp for the purpose of ob- 

 taining greater light-distribution; it can only be used with advantage on direct current. This type 

 is constructed in a form suitable for all kinds of projection in connection with an optical bench, in ad- 

 dition to a form adapted for the continuous projection of diapositives, this last pattern resting on short 



legs and having a cooling chamber but no optical bench. 



4. The Epidiascope a large projector for reflected and transmitted light, where the demands 

 on it are great; it does not, however, possess the many-sided adaptabilities of our A and B types. 

 as ii ha* not an optical bench. 



5. The Megadiascope --a Universal Projection Apparatus, which satisfies every demand pe- 

 culiar to teaching, and this in the most thorough manner. It permits of all kinds of projections being 

 carried out and possesses an excellent source of light in its 25, 30 or 50 ampere arc lamp. A complete 

 description appears at the end of this list. 



6. A few special types of scioptica suitable for the projection of photos and apparatus by 

 transmitted light; the Kolbe projector and the apparatus for the permanent projection of animated 

 pictures, which can also be used for photos. 



The Projectors with Optical Bench can be put to the maximum variety of uses as the appa- 

 ratus are set up on the optical bench in the open between the condenser and the objective. Also, by 

 removing the objective it is possible to place on the optical bench all those auxiliary apparatus which 

 will be described later on in this list, for the purpose, e. g. of the episcopic projection of opaque objects, 

 projection of horizontally-placed objects, microscopic projection, in addition to other experiments 

 in connection with optics and heat. 



It is of advantage to order a lantern resting on tall legs. This arrangement has for its primary 

 object the fact that the images, when the lantern is stood upon a table of the ordinary height, can be. 

 projected over the heads of the audience; while on the other hand independent apparatus can be set 

 up in front of the lantern on taking away the optical bench. For many pieces of apparatus, e. g., An- 

 drews' press for the compression and liquefaction of carbonic acid, for burettes and thermometers. 

 as well as for experiments in connection with which burners must be placed under the optical bench, 

 a projector of corresponding height is necessary. In addition, the projector is easier to handle when 

 above the table top. as in this case it is possible to carry out any operation in connection with it. such 

 as regulating the lamp, focussing the picture, changing the diapositives, etc., etc., without any stoo- 

 ping on the part of the operator. The low type of lantern is specially suited for travelling lectures, as 

 it takes up little space. 



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