Snelling, Henry Hunt, 1816-1897 · [New York : W.B. Smith] · leaf 342
and place under it the same, or anyphotographic preparation, it will be foundto darken as rapidly as if no glass had beeninterposed between it and the sun. Now, if we take a pale yellow glass, andplace it so that the prismatic rays must per-meate it to reach the sensitive surface onwhich we desire… … siz^s of the chromatic bands. Notwith-standing the amount of light impingingalong this line, no change whatever takesplace upon it. Preserving the prism a, theyellow ylass b, and the paper c, in the samepositions, place a mirror at d, so that thesunbeam is strongly reflected on the paper :it will…
Photography · Art and photography
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