Page:The Art of Bookbinding, Zaehnsdorf, 1890.djvu/211

Rh They should be damped, and evenly trimmed and pasted all over with thin best glue or starch, and well rubbed down with a piece of clean paper over the print. If any of the glue or starch oozes out from the sides, it should be wiped off with a clean damp sponge. As photographs lose their gloss in mounting, they must be rolled afterwards in order to restore it. A special machine is used for this. But it may be wished to introduce the silver print without mounting on a board. To do so, and to keep the print straight, paste a very thin paper on the back, stretching the paper well; this will counteract the pulling power albumen has, and the print will, if this be done properly, remain perfectly straight and not curl up. Albumen.—Desiccated egg-albumen is now well known in the market in the form of powder. Three teaspoonfuls of cold water added to every ½ teaspoonful of powder represents the normal consistency of egg-albumen. The manufacture of egg-albumen in the neighbourhood of Moscow is carried on in the houses of the country people. The albumen however is generally roughly prepared and of bad appearance, and often spoils. But egg-albumen is also produced on a manufacturing scale in the neighbourhood of Korotscha, the largest establishment there numbering sixty to seventy workwomen, using about eight million eggs yearly, other establishments using less in proportion. Albumen is also largely manufactured from blood; 5 oxen or 20 sheep or 34 calves are said to yield the same quantity of dry albumen, viz., 2 lbs. In producing blood-albumen for commerce, the objects borne in mind are the attainment of a substance whose solution is free from colour, possesses coagulation, and which is cheap. To prevent tools, machines, etc., from, rusting.—Boiled linseed oil, if allowed to dry on polished tools, will keep them