—, —, duration of, xxv, 115.
—, —, on the changes of wind during, xxv, 116; xliii, 268.
—, —, direction of wind and course of storm different, xxv, 115.
—, —, oscillations of the axis of rotation, xxv, 118.
—, —, centre of, a region of calms, xxxiii, 61.
—, —, opposite sides of a whirlwind often unequal in breadth, xliii, 275.
—, —, fluctuations of barometer accompanying the passage of, xx, 45; xxv, 117.
—, —, fall of barometer a result of the gyration, xx, 45; xxxi, 127.
—, —, barometric indications extend beyond the limits of the action, xlii, 114.
—, —, causes of some irregularities, xxxv, 203.