305. The suggestions which follow are for the practice of landscape or out-door photography especially, though embracing what is helpful also in making architectural subjects, interiors, groups of persons out of doors, and in fact all classes of work outside of the studio. Landscape photography, proper, is the most fascinating and delightful department of the art Every live portraitist should have an outfit for such work, and use it for recreation and diversion and practice, if for nothing else. The general rules as to the manipulation of the plate, printing, and finishing, apply here just the same as in portraiture. And, indeed, the same lenses and

305. The lenses proper to employ for landscape pictures are both single and double; the first to be used when the subject is of that nature that some size is required, and that it will not suffer by a lengthened exposure; the best diameters are two and a half and five inches, covering respectively eight inches by six, twelve inches by ten, and sixteen inches by twelve; the aperture to be used will be better reasonably small, if the subject is well illuminated, since, under that condition, the extreme planes of distance will be more perfectly rendered. The triplet, especially, when refinement of treatment is desirable; Ross' wide-angle doublet, and Dallmeyer's wide-angle rectilinear, in many situations where it is necessary to take the subject at close quarters, and the double portrait combination where, at small sizes, a favorable opportunity is seen for quasi-instantaneous treatment of passing effects of chiaro-oscuro. Many very charming effects of aerial perspective, marking the different planes of distance, in undulating or mountainous country, are obtained by working towards the sun. This must be done when it is not too near the horizon, as then the light would look directly into the lens. Such treatment of the subject requires precaution to avoid fogging; it is well to shield the lens, whether single or double, by a dark cloth, which can be held above. - Lake PricE.

Opticians have been always ready as far as lies in their power to meet the wants of photographers, and great praise is due to them for the patient research and calculations to produce the splendid instruments now placed in the photographer's hands; still, it is just possible that, practically, we may have too much of a good thing, and overstep the mark in our eager desire to produce perfection. This was first seen in the early wish to obtain a perfectly-sharp focus, if only in one plane, but which has now given way to a desire of a more general and artistic effect by diffusion of focus in portraiture over the whole subject. The same thing, in a different way, has now taken place in consequence of a great demand for lenses giving rectilinear lines with wide - angles, which practically, as I hope soon to prove, are not (240) apparatus may be used, but, as explained in Lessons B and C, the best results are obtained outside by the use of such as are constructed purposely for this class of work. In the matter of lenses, the single, double, and triple combinations are all employed, and, to one doing much outdoor work, they are all necessary.

306. Here also the use of the diaphragm or "stop" must he well thought over as explained in Lesson C, and again the lens must be chosen so good as those giving a slight amount of curvature, as in the old-fashioned single lenses, and which has been reduced to a good working minimum in the wide-angle single lens. To show this, set up two cameras - one with a rectilinear wide-angled, and the other with the wide-angled single lens, both having the same focus and angle. Place them before a square building occupying the best part of the largest plate the lenses will cover; level the cameras and cut off excess of foreground, and now examine the two pictures on the ground-glasses. The one with the rectilinear lens will be found to have a wedge - shaped image - that is, the top of the building will be wider than the lower part; whereas that by the single lens will be found to be exactly straight. This is what might have been expected; for if we measure the lines from the centre of the lens to the ground-glass opposite to it, and then from the lens to the lop of the building, of course the latter is much the longer, which will account for the enlargement of the image. The single lens giving a barrel image will, under this circumstance, give a perfectly straight one. The only way to at all modify the picture by the rectilinear lens is to tilt the ground-glass of the camera. It is only when pushing the lenses to extremes that this will occur; but, as under any other circumstances the curvature of the improved single lenses is practically nothing, photographers will in general find them more truthful than any double rectilinear ones. - Francis G. Eliot.

806. Use the smallest stop possible under existing conditions. The circumstance limiting time usually is motion in the subject. Water in motion, swift - moving clouds, or atmospheric effects, must be taken instantaneously, or their chief beauty is lost. In such cases, detail must of necessity be sacrificed. Foliage in motion, trees swaying in the breeze, should never be attempted. If it is worth doing at all, it is worth doing well, and it pays to wait. Exposures on the quiet landscape, on rock and mountain scenery, or on architectural subjects, need be limited only by the necessities of your process and the time at your disposal. I have the Morrison, Ross, Zentmayer, and the "E. A."style of lenses for general use, working each as occasion requires. For landscape work, where straight lines are not essential, I prefer the simplest and cheapest of all - the single combination. I have taken passible marine views instantaneously with each. Under other less favorable conditions and subjects, I have secured good results with a fifteen minutes' exposure; ordinarily the time given varies from ten to sixty seconds. - S. R. StoddaRd.