A Manual Of Photography

APPARATUS NECESSARY EOR PHOTOGRAPHY ON PAPER. 197 such glasses as have a tint of yellow or red, these colours pre- venting the permeation of the most efficient rays. Figures 41 and 42 represent such a frame in its most simple form ; the first showing it in front, as it is employed in taking a copy of leaves, and the other the hack, with its piece of stout tinned iron, or hoard, which presses on a cushion, securing the close contact of the paper with every part of the object to be copied, and its brass bar, which, when pressed into angular apertures in the sides of the frame, gives the required pressure to the paper. To copy leaves we proceed thus:— 42. Having placed the frame face downwards, carefully lay out, on the glass, the object to be copied, on which place the photo- graphic paper very smoothly. Then cover this with the cushion, which may be either of flannel or velvet, fix the metal back, || and adjust it by the bar, until every part of the object and paper are in the closest contact. For all ordinary uses, tins frame answers exceedingly well; but a| more convenient pressure frame? is constructed in the manner represented by Fig. 43. This contains two bars, one of them moveable, and both of them, may be fixed in any required position by binding screws. In arranging botanical specimens, the under surface of the leaves should be next the glass, their upper and smooth surface in contact with the paper. Although very beautiful copies may be taken of dried specimens, they bear no comparison with those from fresh-gathered leaves or recently collected plants, of which, with the most delicate gradations of shades, the veins of the leaves, and the down clothing the stems, are exhibited with in- comparable fidelity. In the event of the plant having any thick