This applies also to a grass lawn or meadow. All that will be required for the trunk of a tree will be to warm it up with burnt sienna, well thinned. (J. J. Houston.)

(of) When preparing photographic transparencies for colouring, do not treat them in precisely the same way as if intended to be used without colour. If you examine a fine slide, by any well-known maker, embracing rural scenery with much foliage, it will be found that whereas in nature the foliage was green, of a more or less bright hue, in the photograph it is many shades darker than it should be, owing to the number and density of the atoms of the silver composing the foliage, this being the case to such an extent as to prevent the green pigment from showing at all.

This is quite a different matter from painting a photograph on paper or porcelain, for, in these the blackest shadows or heaviest foliage can be lighted up at pleasure by the use of opaque or body colours, or by mixing a little flake white with the transparent pigments which alone are applicable to transparency painting. But if, in a transparency, recourse were had to this procedure, it would make things worse than before, for the luminous equivalent of flake white when applied to paper is, in a transparency, the thinning of the deposited silver so as to allow more light to be transmitted, the touch of pure white light given to form the highest light in the one finding in the other its equivalent in the complete removal of the image by the needle point or penknife, so as to leave nothing but bare glass.

To one who has had some experience both in making and colouring transparencies, it is not difficult to obtain the best class of photograph for receiving colours with effect, although it may prove difficult to describe the characteristic features of such photographs. Perhaps the best idea will be conveyed by saying that it ought to be "outlines," and even its outlines should not be too dense. A very brief exposure and rather long development afford the keynote to the nature of the manipulations requisite to secure the best effect.

Plates prepared by the old-fashioned tannin process, and developed by acid pyro and silver, give an effect peculiarly well adapted for receiving colour in the highest style of the art; but the exposure must be short and the development forced. When the picture is laid face down on a sheet of white paper, the appearance presented should be that of a properly printed proof upon paper, while the intensity, when raised up and looked through, mast show a sufficiency of vigour.

Having obtained a suitable transparency, it must next be varnished. Some years ago I adopted the use of a varnish composed of sandarac dissolved in methylated spirit. It gave a clear, bright film, and both oil and water colours took to it nicely; but I sometimes had occasion - as every painter of lantern slides will have to do more or less frequently - to pick out bits, and put in, or rather take out, touches of high light by means of the needle-point. I found, however, to my extreme dissatisfaction, that the collodion film would chip and break off round the spot upon which I operated, and that if I drew fine lines by my scratch-point they became jagged and broken. Being recommended to try white hard spirit varnish diluted with alcohol, I did so with a result even worse than before. Having read of the virtues of castor oil when added to a plain sandarac varnish, I tried it with excellent effect.

I have also employed, with the greatest degree of success, a solution of albumen composed of the white of an egg beaten up with twice its volume of water together with 10 drops of ammonia. After the frothy mass- has settled, the clear liquid is poured off. To use it the transparency is flooded with the liquid, which is then drained off at one corner and the picture immediately immersed in a tray of hot water, the temperature of which is but little under the boiling point. This coagulates the albumen, leaving it not only of a glassy degree of brightness, but modified in such a manner as to render it unaffected by either water or oil paints, while it is susceptible of the most delicate touches of another class of pigment, which I shall describe before concluding.

The question now arises: What class of colour is best for transparency printing - oil, water, or varnish? This cannot easily be answered; each has its own advocates. They are all good in their way, and there are some transparency artists who employ them all even in one picture. As oil pigments appear to enjoy the greatest amount of popularity, I will speak of them first. Although nearly every dealer in lantern appliances keeps boxes of colours for sale, it will be advantageous, especially for the beginner, to purchase from artists' colourmen, under their definite names, the various colours required. They are conveniently put up in tubes and are sold at a very low price - Ad. and upward. It must also be noted that only very few pigments can be employed, owing to the paucity of such as are quite transparent; hence the expenditure for an outfit is very small. For blue, Prussian blue forms the most useful among all the blue pigments, and one can get along very well indeed without any other, although there are some subjects in which Payne's grey comes in handy. There are other transparent blues, such as Chinese blue and cyanine blue; but the Prussian is susceptible of such, easy modification by the admixture of others that no other is really required.

The best yellows are gamboge, Italian pink, and yellow lake. There is but little difference between the two last, although the former of them is probably the more advantageous. The gamboge is useful for foliage, and with a small proportion of Prussian blue forms a good green. Both raw and burnt sienna must be procured. The former is useful in the representation of light, dry, sandy earth, dry roads, and light-coloured houses; the latter is a very transparent brown of an orange tint. Both Vandyke brown and burnt umber are useful, but much less so in a photographic transparency than in other classes of work, because any subjects which were of these tones in nature will be represented so very darkly in the photograph as to require scarcely any colouring at all. Crimson lake and pink madder complete the list. The latter by itself dries very slowly, but by the admixture of megilp or mastic varnish its drying is quickened. This applies also to the Italian pink. A tube of lampblack, by which to render any portion more or less opaque; a tube of megilp, for use as a vehicle; and a bottle of mastic varnish and pale drying-oil, together with a few sable brushes, a palette, palette-knife, and large camel-hair brush complete the outfit.