exhibited in the form of a great whirlwind, 21;
tornadoes, generally, revolve on an axis of rotation and move with the main currents, 22;
a consequent retrograde motion on one side of the axis and progressive on the other side, 23.
—, storm of August, 1830, xx, 34;
second storm of August, 1830, 39;
storm of October 1, 1830, 41;
fall in the barometer due to the gyration of storms, 45.
—, on the hurricane of August, 1831, illustrating the position that storms and hurricanes are gyratory in action, and move with the general current of the region in which they occur, xxi, 191.
—, on the hurricanes and storms of the West Indies and the coast of the United States, xxv, 114;
–uniformity of general character of; originate in tropical latitudes; greatest energy towards their interior; drifted by the prevailing atmospheric current; velocity of progression, 114;