. A London encyclopaedia, or universal dictionary of science, art, literature and practical mechanics : comprising a popular view of the present state of knowledge : illustrated by numerous engravings, a general atlas, and appropriate diagrams . deupon its construction. Theone represented in the an-nexed diagram is the celebra-ted B. Martins improvementon Wolfiuss anemometer.—An open frame of wood, ABCDEFGH1, is sup-ported by the shaft or arbor the two cross-pieces II K,L M, is moved a horizontalaxis Q M, by means of thefour nails, ah, on, Of, gh,exposed to the wind in a pro-per manner. U
. A London encyclopaedia, or universal dictionary of science, art, literature and practical mechanics : comprising a popular view of the present state of knowledge : illustrated by numerous engravings, a general atlas, and appropriate diagrams . deupon its construction. Theone represented in the an-nexed diagram is the celebra-ted B. Martins improvementon Wolfiuss anemometer.—An open frame of wood, ABCDEFGH1, is sup-ported by the shaft or arbor the two cross-pieces II K,L M, is moved a horizontalaxis Q M, by means of thefour nails, ah, on, Of, gh,exposed to the wind in a pro-per manner. Upon thisaxis is fixed a cone of wood,M N O; upon which, as the sails move round,a weight R, or S, is raised by a string round itssuperfices, proceeding from the smaller to thelarger end N O. Upon this larger end or baseof the cone is fixed a rocket-wheel k, in whoseteeth the click X falls, to prevent any retrogademotion from the depending weight.—The struc-ture of this machine sufficiently shows that itmay be accommodated to estimate the variableforce of the wind; because the force of the weightwill continually increase as the string advanceson the conical surface, by acting at a greaterdistance from the -vis of motion; consequently,. ANE 295 ANE if such a weight be added on the smaller partM, as will just keep the machine in equilibrioin the weakest wind, the weight to be raised asthe wind becomes stronger will be increased inproportion, and the diameter of the cone, N O,may be so large in comparison to that of thesmaller end at M, that the strongest wind shallbut just raise the weight at the greater end.—If,for example, the diameter of the axis be to thatof the base of the cone, N O, as one to twenty-eight ; then, if S be a weight of one pound at Mon the axis, it will be equivalent to twenty-eightpounds when raised to the greater end: if there-fore, when the wind is weakest, it supports onepound of the axis, it must be twenty-eight timesas strong to raise the weight to
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Keywords: ., bookcentury1800, bookdecade, booksubjectaeronautics, bookyear1829
