When wind velocities obtained by pilot balloons are compared with those by kites and with observations on mountains, it is found that the speeds by pilot balloons, and to a lesser extent by kites, are quite deficient above 3 km, and to a lesser extent above 2 km, and even above 1 km, in the strongest winds. The ratios of mountain-top to free-air velocities in summer are approximately 1.2 at 1 km and 1.35 at 2 km; and in winter, 1.5 and 1.75, resp. Extreme velocities are estimated as essentially the observed balloon values of 40 m/s at ½ km, 50 m/s, slightly greater than by balloon, at 1 km, and 62, 74 and 88 m/s, up to double the greatest observed balloon, at 1½, 2, and 2½ km.—C. F. B.

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*Paper presented at Durham, N. H. Meeting, June 1941. (Prepared in a climatology course at Harvard University under Dr. C. F. Brooks and Dr. V. Conrad.)