Collins, A. Frederick (Archie Frederick), 1869- · New York, London, D. Appleton and company · leaf 149
flame on the card-board screen you will have to move the lens toward and awayfrom the cardboard, and this process is called focusing. If youwill fix the lens in the front of a light-tight box and place a sheetof ground glass in the back of the box you will have a simple,though crude, camera. 128… … Fig. 139.—Forming an Image with a Lens. The eye is almost as round as a ball and it can be turneda little in its bony socket in any direction. The outer part ofan eye which takes the place of the box of a camera, is stretchedround the whole eye like the cover of a baseball, as shown in
Astronomy · Stars
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