The tornadoes of the western coast of Africa, the pamperos of South
America, and the northers of North America appear to be of a different
character, and not to possess a revolving motion. The sirocco of Italy
and Sicily, and the solano of Spain, as also the simoon of Arabia, and
the harmattan of western Africa, are all winds which owe their origin to
the heated surfaces of Africa and Arabia. The principal difference
between these winds appears to be, that the sirocco and the solano
acquire some moisture in their passage across the Mediterranean, and
therefore do not possess that extreme degree of aridity which forms the
distinguishing character of the simoon and the harmattan.