warm, then it will penetrate the skin of the metal and one may gain a thin and even film, hard enough to form a surface fit to receive paint.

Many places, such as  "the under and inner sides of girders, bolt heads and nuts, rivets, etc., which should be painted with great care to prevent the incursion of water, are often overlooked or neglected. To aid inspectors, a proper check upon the workmanship can be secured by selecting different colors for the several coatings, so that uncoated or defective places may be readily detected."—(Andés.) It is also important that connecting parts, that is to say, joints and fittings be heavily coated with a lute, preferably of red lead, before the work is assembled.

A distinguished British painter and author writes: "The  less  paint that is put