CH.IXa} 



PROJECTION MICROSCOPE 



26yd 



FIG 213 D. The Bausch & Loinb Optical Co* s projection apparatus for objects 

 in liquids, etc. As shown the direction of the beam from the lamp is reflected up- 

 ward by a 45 degree mirror and after traversing the object and the microscope or 

 ordinary lantern objective, it is again changed go degrees by means of a prism and 

 passes off horizontally to the screen. From the prefection of the reflecting appliances 

 very little light is lost. (From the Jour. Ap. Micr. Vol. VI} 



426. How to demonstrate with the Micro-Projection Ap- 

 paratus. Microscopical preparations are not so easily used as are lan- 

 tern slides. The writer has found that the most successful method is 

 for the teacher himself to stand by the apparatus, insert the specimens, 

 and find exactly what he wishes his pupils to see. Then to point 

 them out a bamboo fish pole with sharp end is used. This should be 

 2-3 meters long and if held out in the diverging cone of light leaving 

 the microscope, a sharp shadow will be cast upon the image. With 

 this pointer one can indicate the part to be demonstrated even more 

 satisfactorily than as if he pointed them out directly on the screen. 



-427. Cleaning the Glass Surfaces of the Micro-projection 

 Apparatus. Inasmuch as it is so difficult to make the light sufficienly 

 brilliant for micro-projection, it is of the greatest importance that all 



