The currents of the atmosphere display an endless variety in their velocity and force, from the zephyr, which scarcely stirs the leaves of the forest, to the gale under which its mightiest branches bend, and the hurricane which tears up its trees by the roots, and destroys the habitations of mankind. It has been observed that in the temperate zone the most violent winds occur, when neither the heat nor the cold common to such localities are at its maximum—that they generally extend over a considerable tract of country—and are accompanied by sudden and great falls in the mercury of the barometer. The latter circumstance attends the storms of the tropics, but they are often confined within narrower limits than the extra-tropical hurricanes. It was noticed by the superstitious as a coincidence, not without meaning, that at the time of Cromwell’s death the enchained winds were liberated, and went forth raving and howling through the land, uprooting the largest trees, and whirling them about like straws, and toppling down chimneys and turrets; but the same tempest, at the self-same hour, dashed the vessels of the Baltic sea even upon the strand, and buried Venetian argosies in the Adriatic, shivered the pines of Norway, and swept before it the cypresses of the Bosphorus—a similar war of the elements attending the termination of the earthly career of Cardinal Wolsey, Bonaparte, and George IV. Sometimes the upper regions of the atmosphere have been remarkably agitated, while the lower stratum of the air has been quite calm. Lunardi, on one occasion, traveled at the rate of seventy miles an hour in his balloon, while at Edinburgh; when he ascended, the air was quite tranquil, and continued so throughout his expedition. To ascertain the velocity and force of winds, a variety of experiments have been made with instruments constructed for the purpose. The following table contains some results obtained by Smeaton, inserted in a volume of the Philosophical Transactions:— VELOCITY OF THE WIND.