. Journal of electricity, power, and gas . ceed now from thet8o° line along the sloping line to the 160° vertical line,and thence horizontally to either margin. It is nowfound that but 5;^ will be transmitted. Dividing50 by S/i gives gyi inches, the necessary belt width. When very small pulleys have to be used withlarge belts there is less tension permissible owing tothe injury resulting from bending. This is providedfor in the diagram by the diagonal lines drawn fromthe lower right-hand corner. If, for instance, the beltabove determined were to be used on a 12-inch pulley,follow horizont
. Journal of electricity, power, and gas . ceed now from thet8o° line along the sloping line to the 160° vertical line,and thence horizontally to either margin. It is nowfound that but 5;^ will be transmitted. Dividing50 by S/i gives gyi inches, the necessary belt width. When very small pulleys have to be used withlarge belts there is less tension permissible owing tothe injury resulting from bending. This is providedfor in the diagram by the diagonal lines drawn fromthe lower right-hand corner. If, for instance, the beltabove determined were to be used on a 12-inch pulley,follow horizontally along the 514 line to the 12-inch pulley diagonal line and thence vertically upwardto the small pulley scale at the top. It is seen thatbut 44 could be transmitted in this case. It isseen by observing the diagram that the power trans-mitted increases with the belt speeds up to a certainmaximum value beyond which it decreases, finally March 19, 1910) JOURNAL OF ELECTRICITY, POWER AND GAS 253 § ^ ^ . ^ ^ . § . § ^ I ^ ». DIAGRAM FOR FINDING HORSEPOWER TRANSMITTED BY BELTING For Lxplanation see pace ISl. 254 JOURNAL OF ELECTRICITY, POWER AND GAS Vol. XXIV—No. 12 falling to zero at about 10,000 ft. per minute for doublebelts. This is simply the graphical explanation of theeffect produced when high pulley speeds are en-countered, and is the plotted results of the mathe- matical equation where the term approaches and reaches unity. From a series of observations extending over aperiod of nine years, Mr. F. W. Taylor (see A. S. M. Vol. XV., p. 204) drew the following conclusionsrelative to belting practice: A double belt, havingan arc of contact of 180° will give an effective pull onthe face of the pulley of 35 pounds per inch of beltwidth. The number of square feet of belt passing arounda pulley per minute required to transmit one horse-power is 80 ft. for oak tanned and fulled leather beltsand 90 for other types of leather belts. The numberof lineal f
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