A Manual Of Photography

CHAPTER I. EAKLY RESEARCHES ON THE CHEMICAL ACTION RAYS. OF THE SOLAR 18 instructor s fn T. first indication of Ä ff ?. dlscover^ from the and its + th’ to the Pb^od of its full development, progress of Z ^ .Purposes of ornament or utility. The Kens that a Warily a slow process, and it often for IÖ Z act 18 slowed to he dormant for years, or or ages, which, when eventually revived, is found to render a fine interpretation of some of Nature’s harmonious phenomena. I ° "° wants or the pleasures of existence Photography is peculiarly illustrative of this position. tionexS 01 ^gnity appear to have had their atten- tion excited by many of the more striking characters of liZ Yet we have no account of their having observed any of its ehe mica influences, although its action on coloured bodies--deepen' mg their colour in some cases, and discharrnurr must have been of everyday oe^rrenee ThS they have recorded are, that some precious stones mrticidariv the amethyst and the opal, lost their sparkh b/^^ exposure to the rays of the sun. 1 7 prolonged