A.-PHOTOGRAPHS WITH CORRECT LIGHTS AND SHADOWS.

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remaining transparent over the spaces occupied by shadows, it must beevident that a copy taken by application on the white paper, from sucha photograph, must be the opposite of the original photograph, that is, itwill exhibit shadows, demi-tiuts, and lights, in their correct order.

It will be found that a negative copy from an engraving, provided itbe carefully taken, possesses all the sharpness of the original, howeverhighly it is finished, but this is not the case with the second, or positivecopy; this will be fainter in its shadows, and will want that definednessof outline which is the great beauty of a picture.

The principal causes of this are, the want of perfect opacity in thedarkened silver in which the picture is traced, the great difficulty of re-moving every portion of the silver from the transparent parts, and theimperfections of the paper, which are in general much increased by theprocesses to which it is subjected in the preparation of the ground andthe fixing of the photographs.

Of course, if a negative photograph is intended to be used for multiply-ing an original design, it is essential that the utmost caution be observedin every part of the process. The shadows should be very deep, andof great sharpness, and the lights perfectly free of any stains. Havingprocured a negative photograph of the required excellence, we may pro-ceed to take a copy of it in the same manner as I have directed engrav-ings should be copied. This will, however, rarely give a photographequalling in any respect the sharpness of the one of which it is a transfer.Had this been done, the great end of the photographic art would havebeen attained, and this treatise might have been illustrated by speci-mens of the art it attempts to describe.

There is another mode of proceeding which requires some care, butwhich produces a much better effect. Two negative photographs aretaken from an engraving, and carefully fixed; they are then to bodelicately adjusted, face to back, so that all their lines exactly corres-pond ; being fastened in this position with fine needles, they are to becemented together at the edges with a little gum, and kept under a slightpressure until quite dry. This double photograph may now be used toproduce positive drawings from in the same manner as if single. I havefound it advantageous to damp the paper in some cases, which increasesits transparency, but it renders it liable to injury by dissolving out thenitrate from the paper with which it is put in contact, A plan of var-nishing might, I have no doubt, be devised, which would prove highlyadvantageous, in the way of photographic transfers. It need scarcelybe stated that these positive drawings require the same methods forfixing them as have already been described.

Owing to the faintness of the light which acts on the paper in thecamera, the depth of shadow in the resulting photograph, is much lessthan iu drawings procured by the direct rays of the sun; consequently,the transfer from a camera picture is still more imperfect than one fromthe other kinds of photographs. I have tried various plans to increasethe effect, but none have been attended with very good results. It must

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