=Winds of Middle Latitudes.= Now study Figure 12 and associate the information it conveys with that of Figure 13, and observe that from the two belts of high pressure the air is pushed outward on both sides. In each case it starts as a true north or south wind, but, due to the rotation of the earth, is always and everywhere deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, and this deflection increases until what started as a poleward wind in the middle latitudes soon becomes almost a due west wind. In this region of west winds cyclonic storms are more frequent than in any other part of the globe. Now get clear in the mind the fact that no matter what may be the direction of the wind inside a cyclonic or anti-cyclonic whirl (often one thousand miles in diameter), the whirl is carried toward the east by the general drift from the west of the winds between latitudes 30° and 60°, and toward the west in the region of the trade winds. =Low Barometer at the Poles.= Even though the air is contracted and rendered denser by the great cold of the Arctic regions, the pressure remains low because of the quantity of air driven equatorward by the centrifugal force both of the earth and of the winds themselves as they rim ahead of the earth and encircle the globe in the middle latitudes. =Data too Meager to Show Full Circulation Aloft of the Atmosphere of the Globe.= Many charts have been published in the attempt to show how the atmosphere circulates below and aloft through the whole world. They only have speculative value, as our knowledge is too limited to permit us to unravel the complexities of all the upper movements.