Page:The wonders of optics (1869).djvu/188

 so concentrated as to project a brilliant beam of light through the painted slide, which being in the conjugate focus of the large plano-convex lens d, the pictures on the glass are refracted in a magnified form on the white cloth.

The magic lantern, therefore, consists of a box to hold the lamp, a concave mirror, and a convex lens to concentrate the light on the slide, and a second convex lens to throw the image on the screen.