The way the reflectoscope works is like this: the picture is projected upon the screen in virtue of the fact that the direct light from the lamp, as well as that portion of it which is reflected back by the tin, is thrown against the surface of the picture or object held in the opening; from this the light is reflected through the lens which enlarges it and projects it on the screen.
How to Make a Magic Lantern.
—To make a magic lantern out of a camera is just as easy as it is to make a reflectoscope but you will have to buy a condensing lens[60] and this will cost 50 cents to $1.00, according to size.
[60] The L. E. Knott Apparatus Co., Boston, Mass., sells a 2 inch condensing lens for 50 cents; a 3 inch one for 75 cents, and a 4¹⁄₂ inch one for $1.10.
For this lantern you can use either a box or a bellows camera, though the latter is better because the picture can be focused. Whichever you use make a base of a 1 inch thick board, 5¹⁄₂ inches wide and 14 inches long and nail or screw two strips of wood ¹⁄₂ an inch wide, ³⁄₄ inch high and 8 inches long along the edges on one side as shown at [A in Fig. 60].
If your camera is of the box kind set it in between the strips on the base on the front end, but if it is of the bellows type then you will have to make a shelf for it as shown at [B] to hold the camera in place as shown at [C].
Next make an illuminator as [described] above in the text How to Make an Enlarging Apparatus, but instead of covering the front with ground glass make a board to fit it and cut a hole in it the exact size of the condensing lens. This lens is a plano or a double convex lens as shown at [D] and while it should be 4¹⁄₂ inches in diameter to get all of the picture on the screen you can use a lens as small as 2 inches though all of the picture will not show.
 | ||
| THE BASE OF THE LANTERN | THE FRAME TO HOLD A POCKET FOLDING CAMERA | HOW THE CAMERA IS FIXED TO THE FRAME |
 | ||||
| PLANO CONVEX | DOUBLE CONVEX | ONE OF THE LANTERN SLIDE HOLDERS | FRONT BOARD ILLUMINATOR | |
| CONDENSING LENSES | ||||
Fig. 60. the parts of a home-made magic lantern