STORMS, HURRICANES, AND TYPHOONS. 399 



tlie wind in May sets one third of the time from Avest. But in 

 A, which is between the same parallels, the favourite quarter for 

 the same month is from S. to S.W., the wind setting one third 

 of the time from that quarter, and only 10 out of 221 times 

 from the west ; or, on the average, it blows from the west only 

 IX day during the month of May. In B, notice the great " sun 

 swing " of the winds in September, indicating tliat the change 

 from summer to winter, in that region, is sudden and violent ; 

 from winter to summer, gentle and gradual. In some districts 

 of the ocean, more than a thousand observations have been dis- 

 cussed for a single month, whereas, with regard to others, not a 

 single record is to be found in any of the numerous log-books at 

 the National Observator}^ 



782. The China seas are celebrated for their furious gales of 

 Typhoons. wiud, kuown among seamen as typhoons and white 



squalls. The seas are included on the plate (VIII.) as within 

 the region of the monsoons of the Indian Ocean. But the mon- 

 soons of the China Sea are not five month monsoons (§ 681) ; 

 they do not prevail from the west of south more than two or 

 three months. Plate V. exhibits the monsoons very clearly in a 

 part of this sea. In the square between 15° and 20^ north, 110° 

 and 115° east, there appears to be a system of three monsoons; 

 that is, one from the north-east in October, November, Decem- 

 ber, and January ; one from east in March and April, changing 

 in May; and another from the southward in June, July, and 

 August, changing in September. The great disturber of the 

 atmospheric equihbrium appears to be situated among the plains 

 and steppes of Asia ; their influence reaches up to the clouds, 

 and extends to the China Seas ; it is about the changing of the 

 monsoons that these awful gales, called t}^hoons and white 

 squalls, are most dreaded. 



783. In like manner, the Mauritius hurricanes, or the cyclones 

 The Mauritius hurri- of the Indian Oceau, occur during the unsettled 

 c'^^s- state of the atmospheric equilibrium which takes 

 place at that debatable period during the contest between the 

 trade-wind force and the monsoon force (§ 699), and which" 

 debatable period occurs at the changing of the monsoon, and 

 before either force has completely gained or lost the ascendency. 

 At this period of the year, the winds, breaking loose from their 

 controlling forces, seem to rage with a fury that would break up 

 the very fountains of the deep. 



