The warmed air of summer produces an area of low pressure in the west-central United States, which interrupts the belt of high pressure that planetary conditions alone would form around the earth about latitude 30; hence there is a tendency of the summer winds to blow inward from the northern Pacific over the Cordilleras toward the continental centre, and from the trades of the torrid Atlantic up the Mississippi Valley; conversely in winter time, the cold air over the lands produces a large area of high pressure from which the winds tend to flow outward; thus repelling the westerly winds of the northern Pacific and greatly intensifying the outflow southward to the Gulf of Mexico and eastward to the Atlantic. As a result of these seasonal alternations of temperature and pressure there is something of a monsoon tendency developed in the winds of the Mississippi Valley, southerly infiowing winds prevailing in summer and northerly outfiowing winds in winter; but the general tendency to inflow and outflow is greatly modified by the relief of the lands, to which we next turn.
The actual borrowing capacity of the state is limited by its constitution to $300,000, except for the extraordinary purpose of repelling invasion or suppressing insurrection.
At this point Aratus appealed to Sparta to help the Achaeans in repelling an expected Aetolian attack, and Agis was sent to the Isthmus at the head of an army.
In 1528 Jajce surrendered, after repelling every attack by the Turkish armies for 65 years.