186 THE AMERICAN MONTHLY [June, 



an ordinary tin funnel deprived of its lower end and painted 

 dead black inside. To its under side is soldered a strip of tin, 

 this forming a foot. It is screwed upon a piece of wood which 

 has been previously fitted in the above mentioned slot. Be- 

 hind it is the slide holder, made of very light wood and secured 

 to a base fitted in the slot. The upright has a hole cut through 

 it about 4 inch in diameter, through which the image and light 

 pass. Upon the face of the upritgh are two spring fingers for 

 holding the slides. 



Behind this is the brass tul)e which cost 45 cents. It consists 

 of a piece of thin brass pijie, 22 inches long by 2 inches in diam- 

 eter. It has a society screw cut in one end so that it may re- 

 ceive any objective. The inside of the tube must be painted 

 dead black. 



A ring is worked out of a piece of wood of not less than one 

 inch in thickness. The thickness prevents any binding. Cut 

 a small notch for the rack which keeps the tube from turning. 



There is a small pinion that operates the rack. It is therefore 

 necessary to cut the ring in two at the bottom of the rack. This 

 is to allow for the cutting of the recess for the pinion and the 

 shaft for the thumb piece. This is also fastened to a base piece 

 that is fitted into the slot. 



The object glass is simply a ground glass. This takes the 

 place of the ordinary eye-piece, so that instead of viewing an 

 object with one eye through a I inch aperture both eyes are 

 used as in ordinary vision. The ground glass is 6 inches square. 

 The image can be seen on either side of the ground glass. If 

 any white material, as muslin or cardboard, be substituted for 

 the ground glass ; the image can be seen on only one side. If the 

 ground glass and holder be removed and the instrument be 

 I)ointed toward a sheet suspended from the wall ; any image of 

 any desired size may be projected thereupon as in lantern views. 



The center of the funnel, the hole in the slide holder and the 

 lens, which may be any low power, must all be in line. 



Any light from a candle to a lime light may be used but a 

 cheap magic lantern lamp with two wicks is very good. One 

 can be made out of a tin cracker box by cutting a hole in the 

 side on a level with the flame and by inserting a reflector op- 

 posite the hole. 



The apparatus can be used in photography by removing the 



