The Mysians appear in the list of the Trojan allies in Homer and are represented as settled in the Calms valley at the coming of Telephus to Pergamum; but nothing else is known of their early history.
A considerable part of the republic is covered by the equatorial belt of calms, whose oscillations divide the year into a wet and dry season.
This effect is well seen in the way in which the wind blowing directly up the Severn estuary is directed along the edges of the Oolitic escarpment north-eastward, thus displacing the centre of cold in winter to the east coast, and the centre of heat in summer to the lower Thames, from the position which both centres would occupy, if calms prevailed, in a beit running from Birmingham to Buckingham.
The climate of the coast district is hot, moist and unhealthy, with a season of heavy rain lasting from May to November, during which time variable winds, calms and tornadoes succeed one another.
On the Pacific coast the belt of calms, known as the northern horse latitudes, crosses the northern parts of Lower California and Sonora, which accounts for their extreme aridity.