This being the case, then, it must be self-evident that the best mode of procedure will be to _print in skies_ from separate negatives, either taken from nature or from drawings made for the purpose by an artist that thoroughly understands art in all its principles. By these means, especially the latter, skies may be introduced into the photographic picture that will not only be adapted to each individual scene, but will, in every instance where they are employed, increase the artistic merit and value of the composition. But to return to the subject chiefly under consideration. Clouds in landscape pictures, like "man in his time," play many parts--"they have their exits and their entrances." And it is almost impossible to say enough in a short paper on a subject so important to all landscape photographers. I will, however, as briefly and lucidly as I can, endeavour to point out the chief uses of clouds in landscapes. Referring to their use for effects in light and shade, I wrote, at the commencement of this paper, that the engraved translations of Turner afford the most familiar and beautiful examples, which they undoubtedly do. But when I consider that Turner's skies are nearly all sunsets, the study of them will not be so readily turned to practical account by the photographer as the works of others,--Birket Foster, for instance. His works are almost equal to Turner's in light and shade; he has been largely employed in the illustration of books, and five shillings will procure more of his beautiful examples of sky effects than a guinea will of Turner's. Take, for example, Sampson Low and Son's five shilling edition of Bloomfield's "Farmer's Boy," or Gray's "Elegy in a Churchyard," profusely illustrated almost entirely by Birket Foster; and in them will be seen such a varied and marvellous collection of beautiful sky effects as seem almost impossible to be the work of one man, and all of them profitable studies for both artist and photographer in the varied uses made of clouds in landscapes. In those works it will be observed that where the lower part of the picture is rich in variety of subject the sky is either quiet or void of form, partaking of one tint only slightly broken up. Where the terrestrial part of the composition is tame, flat, and destitute of beautiful objects, the sky is full of beauty and grandeur, rich in form and masses of light and shade, and generally shedding a light on the insignificant object below, so as to invest it with interest in the picture, and connect it with the story being told.