Johnson's natural philosophy and key to philosophical charts : illustrated with 500 cuts; being reduced photographic copies of all the diagrams contained in the author's philosophical series of indestructible school charts ; for the use of schools and families (1878)
ss magni-fying power; the object being to concentrate a large amount of lightin such a condition as to allow of distinct vision, to enable the obseiverto see objects distinctly at night. The Camera Obscura. 483. Figure 20.—The camera obscura, as employed b^artists for tracing landscapes, etc.… … In the dark box is provided a plane mirror, M, inclined at an angleof 45°, upon which the rays S, coming from the object or scenery, arereceived, and by which they are reflected upward to a glass plate ortransparent screen, upon which is laid the paper P, and on which thetracing is made. The lens,…
Physics · Astronomy
Internet Archive · University of Connecticut Library · Public Domain Mark 1.0. Free to use for anything.
