A Manual Of Photography

CHAPTER II. ON THE APPARATUS NECESSARY EOR THE PRACTICE OF PHOTO- GRAPHY ON PAPER. The most simple method of obtaining sun-pictures, is that of placing the object to he copied on a piece of prepared paper, pressing it close by a piece of glass, and exposing the,arrange- ment to sunshine: all the parts exposed darken, while those covered are protected from cliange, the resulting pictuie being white upon a dark ground. It should be here stated, once for all, that such pictures, how- soever obtained, are called negative photographs ; and those which have their lights and shadows correct as in nature dark upon a light ground, are positive photographs. The accompanying woodcut, Fig. 37, represents a negative copy of a currant leaf, and Fig. 38, the positive copy obtained from it. If a copy is made by means of the camera of any illuminated object, the picture being produced by the darkening of a white