OUTLINES OF NATURAL PHILOSOPHY. 



The sudden sinking of the barometer almost always 

 indicates a gale of wind, though a gale that is some- 

 times at a considerable distance. When the baro- 

 meter begins to rise, it is a symptom that the gale 

 has reached its height ; and though it may still con- 

 tinue to blow for a long time, it is usually with de- 

 creasing violence. 



422. Notwithstanding these irregularities, there 

 is in most countries a tendency to periodical winds, 

 more or less remarkable, according to the steadiness 

 of the climate. 



Even with us, where an insular situation, with a great 

 Continent on one side, and a great Ocean on the 

 other, unites all the causes of a variable climate, the 

 East wind usually prevails in the spring, from the 

 vernal equinox to the summer solstice, and beyond 

 it ; during the rest of the year, the Westerly winds 

 prevail, though not without frequent incursions of 

 the east, by which our most unpleasant weather is 

 always produced. 



The Etesian, or northerly wind, prevails very much 

 in summer all over Europe. PLINY describes it as 

 blowing regularly in Italy, for forty days after the 

 summer solstice, lib. ii. cap. 47. It is part of the 

 great current that carries the atmosphere of the 

 higher latitudes down to the tropical regions. 



423. The 



