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Page:Popular Science Monthly Volume 18.djvu/237

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charge made by water-boards is from fifty to seventy-five dollars a year per horse-power, while for those used on sewing-machines the charge varies from three to six dollars. The cost for organs is between twelve and twenty dollars for the same time. When the motors are used for business purposes, their owners can usually get special rates depending upon the time they are actually employed. This price per horse-power is not greater than that of steam-engines of large size, and is very much less than the cost of any other form of motor of small power. This price is, however, based upon a condition of water-service which could not hold were the motors much more largely used than at present. The greatly increased demand for water that this would make would necessarily raise the price charged, but it could be very much increased and still leave these motors the most economical of small powers.

Another wheel of a somewhat peculiar construction, invented by Mr. Talley, is capable of being used either as a turbine or an overshot. The water is applied in such a manner that it strikes the wheel in a thin sheet, the sheet being undulating and wave-like in form, and impinging edgewise upon the wheel. The circumference of the wheel is provided with buckets set so as to make an angle of thirty degrees with the radial lines. The flanges forming the sides of the buckets are scalloped out to allow the water to freely escape when the wheel is employed in the former way. The wheel is set eccentric to its casing, approaching it closely on the inlet side. The casing in this portion has a number of curved channels terminating in the face opposite the buckets in a sinuous slit from which the water issues upon the wheel. The inlet-pipe enters this wave line chute at the top of the casing, and the water is distributed throughout it by ducts terminating at different points. A valve at the top admits the water to one or more of these ducts as desired. The wave-line slit in the casing is wider near the top and gradually narrows toward the bottom, so that there is a greater weight of water on the wheel at the upper part, and the water issues with a higher velocity lower down. The sheet of water exerts a continuous pressure upon the wheel instead of moving it by successive impacts as in the case of the former motor. An outlet in the base allows the water to pass off when the wheel is used as an overshot, and one in the side of the casing provides an exit when it is used as a turbine. The wheel is said to be quite economical of water, and to run easily.

For light pieces of machinery, such as the sewing-machine, various sorts of spring motors have from time to time been devised, though none of them seem to have been brought into use. They are not properly motors, and are really quite valueless for the purpose of power, unless it be very slight, as that required in clocks. They are capable of giving out but a small amount of the power expended in winding them up, and, as this labor has to be done by hand, are very uneconom-