Several laws hearing on the winds have been enunciated, Dove maintained the existence of ilternate currents, polar and equatorial. exist iu by side and moving as a whole east ward. lle also showed empirically that there was a certain law (tf sequence according to which the winds followed each other day after day, and which me now know is simply due to the fact that the neljority of the storms pass on one side or the other of the station. Iledtield, and other nil ncetrurelogisls showed that the \yin& circulate around storm venire, a fact which, however, was also known to Dampier and other early voyagers. Bence all large storms linve the character of whirlwinds. Redfield knew, but did not lay stre,s upon the fael, which Meldrum brought out most forcibly, that the winds are inclined at a considerable angle to the radius vector from the storm centre, or to the isobars surrounding the storm centre. .J. Allan Broun and, many years later, Clement Ley and Cleve land Abbe independently announced that the upper winds are inclined to the lower winds in a regular sequence, so that as we ascend in the atmosphere the winds are deflected more and more to the right. Ferrel showed that the in clination of the wind to the isobar depends upon the distance from the storm centre, on the lati tude of the place, and on the coefficient of re sistance of the earth to wind, and he gate the formula connecting these together. Espy and,
many years later, Koeppel], independently, showed that the interchange of air between the upper strata and those near the ground causes the decided diurnal increase in the velocity of the wind in the early morning boars up to a Maximum at the hour when the interchange is most rapid; also that there must be a cor responding diminution of the wind in the upper strata, which diminution has been established by actual observations on mountain tops and other elevated points. The general circulation of the atmosphere is not a simple system of steady upper and lower winds. It has been shown that the dynamics of the air do not allow of the existence of any steady currents maintain ing the dynamic equilibrium. Therefore the system of upper and lower winds devised by Ferrel as the simplest imaginable must be re placed by systems of whirls or eddies, so that the great whirlwinds or cyclones and anticyclones that observation shows on every daily weather Cl)m must be considered as an integral and tial part of fhe general circulation, and would be so even if the globe were a uniform frictionless sphere.