Meteorological observations and essays / By John Dalton.

  • John Dalton
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: Meteorological observations and essays / By John Dalton. Source: Wellcome Collection.

    113/280 (page 87)
    tropic than usual, and therefore the winds about the tropic are more nearly east at that time, and those about the other tropic more nearly north and south. Were the whole globe covered with water, or the variations of the earth’s surface in heat regular and constant, so that the heat was the same every where over the same parallel of latitude, the winds would be regular also: as it is, however, we find the irregularities of heat, arising from the inter- spersion of sea and land, are such, that though all the parts of the atmosphere in some sort conspire to produce regular winds round the torrid zone, yet the effect of the situation of land is such, that striking irregularities are produced: witness the monsoons, sea and land breezes, &c. which can be accounted for on no other principle than that of rare- faction ; because the rotatory velocity of different parallels in the torrid zone is nearly alike.—For this reason we have omitted giving the facts, and | their explanation, as having been done by others. From what has been said, it might be supposed that the winds in the northern temperate zone should be between the north and east below, and between the south and west above, almost as regu- larly as the trade winds: but when we consider the change of seasons, the different capacities of land and water for heat, the interference and oppo- sition of the two general currents, the one of which is verging towards a central point, and the other proceeding from it, we might conclude it next to