Revolutions Velocity of Resistance Resistance Calculated of turn-table wires. Feet of frame of wires. resistance per minute. per minute. and wires. R_3−r=r_3. of wires. Grammes. Grammes. R_3. 9.25 833 65 37.5 25.2 11.55 1040 91 43.5 39.35 11.55 1040 101 53.5 39.35 15.25 1375 160 75.0 68.7 18.1 1630 203 86.5 96.6 19.25 1735 221 92.0 109.5 19.25 1735 216 87.0 109.5 20.63 1860 237 90.5 125.8 The last column of these tables is calculated for a coefficient of form equal to 0.5, which has been found to be approximately correct for a rigid cylindrical body. These tables are not sufficiently extensive to determine accurately the exact resistance that wires of various sizes will offer at given velocities, or to serve as the basis for the deduction of formulæ, and were not made for that purpose. However, from the above data, and the curves plotted in Plate 44, it will be seen that some unexpected results were obtained. [Illustration: PL. 44 RESISTANCE OF WIRES AT GIVEN VELOCITIES] [p167] These results are fairly well summarized in the following general statements: First, that the coefficient of resistance increases to some degree as the size of the wire is decreased; second, that in the case of wires of the size which it was expected to use, and at approximately the soaring speed of the aerodrome, the resistance is certainly not greater than 75 per cent, and more probably less than 50 per cent of the resistance encountered by a flat surface of the same projected area; third, that the coefficient of resistance did not seem to be increased by the vibration of the wires. On the contrary, it was noted during the experiments that when they reached a speed which just caused them to “sing,” there was a marked diminution in the resistance. This statement is made, however, with some reserve, for it is probable that the singing of the wires was due to vibration in the horizontal plane, and it is not definitely known what the effect would be of vibration in the vertical plane.