By the way, we ought to mention that the canvas is in a decidedly limp state during these operations. It has just sufficient stiffness to keep smooth on the screen, and that is all; the treatment it has received appears to have imparted no increase of substance to it. Again it is brought into the red-brick washing apartment, and again treated in one of the white enameled baths as before. This time it is the developer that is contained in the bath, and the small limp tablecloth--for that is what it looks like--after being drawn over the glass rod, is put back into the bath, and the developing solution rocked to and fro over it. The whiteness of the bath lining assists one in forming a judgment of the image as it now gradually develops and grows stronger. Here is the formula of the developer: Pyrogallic acid......................... 10 parts. Citric acid............................. 45 " Water...................................410 " The developer--which, it will be noted, is very acid--is warmed before it is used, say to a temperature of 30 deg. to 40 deg. C.; nevertheless, the development does not proceed very quickly. As we watched, exactly eight minutes elapsed before Mr. Winter cried out sharply, "That will do." Immediately one of the assistants seizes the wet canvas, crumples it up without more ado, as if it were dirty linen, and takes it off to a wooden washing trough, where it is kneaded and washed in true washerwoman fashion. Water in plenty is sluiced over it, and after more vigorous manipulation still, it is passed from trough to trough until deemed sufficiently free from soluble salts to tone. The toning--done in the ordinary way with gold--removes any unpleasant redness the picture possesses, and then follows the fixing operation in hyposulphite. As canvas is more permeable than paper, these two last processes are quickly got through. The final washing of the canvas is very thorough. Again it is treated with all the vigor with which a good laundry-maid attacks dirty linen, the canvas, in the end, being consigned to a regular washing-machine, in which it is systematically worked for some time. When the canvas picture at last is finished, it presents a very rough appearance, by reason of the tiny fibers that stand erect all over the surface. To lay these, and also to improve the surface generally, the canvas is waxed, the fabric is stretched, and a semi-fluid mass rubbed into it, heat being used in the process, which not only gives brilliancy, but seems also to impart transparency to the shadows of the picture. The result is a pleasant finish, without vulgar glare or glaze, the high lights remaining beautifully pure and white.