From both of these examples the photographer may obtain a suggestion, and slightly tint the sky of his picture, rich in objects of interest, so as to resemble the tint produced by the "ruled lines" representing a clear blue sky in an engraving. Hitherto that kind of tinting has generally been overdone, giving it more the appearance of a heavy fog lifting than a calm blue sky. The darkest part of the tint should just be a little lower than the highest light on the principal object. This tint may either be obtained in the negative itself at the time of exposure, or produced by "masking" during the process of printing. On the other hand, when the subject has little to recommend it in itself, it may be greatly increased in pictorial power and interest by a judicious introduction of beautiful cloud effects, either obtained from nature, or furnished by the skill of an artist. If the aid of an artist be resorted to, I would not recommend painting on the negative, but let the artist be furnished with a plain white-sky print; let him wash in a sky, in sepia or india ink, that will most harmonise, both in form and effect, with the subject represented, take a negative from that sky alone, and put it into each of the pictures by double printing. This may seem a great deal of trouble and expense, and not appear to the minds of some as altogether legitimate, but I strenuously maintain that any means employed to increase the artistic merit and value of a photograph is strictly legitimate; and that wherever and however art can be resorted to, without doing violence to the truthfulness of nature, the status of our art-science will be elevated, and its professional disciples will cease to be the scorn of men who take pleasure in deriding the, sometimes--may I say too often?--lame and inartistic productions of the camera. THE USE OF CLOUDS AS BACKGROUNDS IN PORTRAITURE.