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 water. The consistency should be such that, when a little of the paste is thrown at the screen-covered tank, it will stick. Apply the paste with a masons' trowel: the quality obtainable at a five and ten-cent store will be satisfactory.

The first coat is known as the skin coat and should be smoothed on to a depth of about $1/4$ in. and allowed to set about 24 hours, until it dries white and hard. Add layers of the cement until a covering about $3/4$ in. in thickness is obtained. The upper half of the tank should, however, be covered a little more heavily than the lower as the hottest water is always at the top. This is also desirable because, frequently, only the upper portion of the tank contains hot water, due to a low fire or to the water having been drawn off. The thickness of the coating can be determined by sticking a pin through the asbestos to the tank. The rounded top of the tank should also be covered to a depth of 1 in. or more.

Considerable care must be expended on the finish coat. A molders' slick makes the best smoothing tool, although a large spoon, flattened somewhat on the bottom, will do. Cover only about 1 ft. at a time, and smooth it carefully before putting on more. The work can be stopped at any time, as the new wet cement will make a perfect joint with a completely dried section. In order to make the finished surface as smooth as possible, a second smoothing with the slick should be given after the cement has dried for about onehalf hour. If sufficient care is taken, a smooth eggshell gloss will result, which will not only shed dust but will also permit only the very minimum amount of radiation. Many hot-water tanks used in connection with home steam-heating plants are heated by an external copper coil which is so connected that it is completely surrounded by hot water from the boiler. This heater is always at nearly the temperature of boiling water and should consequently be covered with an extra-heavy coating of cement, about 1$1/2$ in.

The first layer should be quite thin, $1/8$ in. or so, as a heavier application will drop off in patches due to the smaller radius and sharper angles of the heater. As the piping between the heater, boiler and tank presents only a small amount of radiating surface, it may simply be painted black with stovepipe enamel. The gas or separate heater used during the summer may also be improved in appearance, while it is standing idle, with a coat of the black enamel.

 



By bolting a complete extra wheel and tire to the regular rear wheels of his Ford cars, a large landowner in the peat-sediment delta of the San Joaquin river in California has solved a difficult traction problem. The soil is of the peculiar ashy, springy type characteristic of reclaimed peat areas, and affords little traction to the ordinary small single tire. The ranch foremen and mechanics must travel from field to field, often when cultivation is going on, and there is no time to make roads. With these double wheels a Ford can go anywhere on the ranch, even across a freshly plowed field. The photo shows how the extra wheel is attached by means of blocks of wood, through which are driven bolts, held in place by iron strips on both sides. The work was done in the ranch shop.—Logan Studio, Stockton, Calif.

