188 LIEUT.-COLONEL SYKES ON THE ATMOSPHERIC TIDES 



east (103) and north-east (143), in five years, amount to 949 : of this number 246 are 

 from the points north-east and south-east, leaving 703 from the east. There is a re- 

 markable paucity of northerly and southerly winds, there being records of the wind 

 blowing from the north only 1 15 times, and from the south but 36 times. Another 

 remarkable feature is the frequent absence of wind, particularly at sunrise ; and more 

 so in the months of January, February, March, October, and November, than in other 

 months of the year. The cessation of wind from the month of May to September in- 

 clusive, is comparatively rare ; and generally throughout tlie year the absence of wind 

 at 4 P.M. may be looked upon as unusual. In five years there are 1720 observations 

 of "No wind," and 847 of these belong to sunrise, 452 to 9 — 10 a.m., and 304 only to 

 4 P.M., and 117 to 10 — 11 p.m. in 1830. An inspection of the Tables will show that 

 there is very considerable uniformity in the direction of the wind in the same months 

 in consecutive years. The westerly winds begin to prevail in March, alternating with 

 the easterly winds, which blow during the latter part of the night, and up to 7 or 8 a.m. 

 At first they are to the northward of west, but they gradually come round to the west, 

 and for the few last days in May and first week in June they are from the south-west ; 

 but when the rains fairly set in, they are limited to west and west-south-west until the 

 beginning of October. In this month they are variable, and the records of " No wind*' 

 increase suddenly and rapidly. A few easterly winds, however, indicate the change 

 which is about to take place ; they gradually increase, and with those from the north- 

 east and south-east, almost entirely supersede the winds from the westerly points. In 

 March, from the sun's approach, the interior land during the day gets heated ; an 

 influx of air from the sea-coast commences after 10 a.m. ; but as the earth at this 

 period cools more rapidly than the sea at night, the interior is cooler than the coasts, 

 and there is a reflux of air towards the ocean ; the easterly and westerly winds thus 

 alternate day and night. This alternation, however, diminishes in the ratio of the 

 sun's increasing power ; and when the earth gets so thoroughly heated that it cannot 

 reduce its temperature by radiation below that of the sea, the consequence is the 

 prevalence of winds from the westerly points to the almost entire exclusion of those 

 from easterly points. In June the west-south-west wind sets in as previously stated. 



The winds are rarely remarkable for blowing with very great violence, unless in 

 the terrific but short thunder storms preceding the monsoon. At these periods trees 

 are blown down, thatched houses unroofed, great damage is done by lightning, and 

 the rain falls in a deluge. At Dholpoor in Hindoostan, in May 1805, I saw Lord 

 Lake's camp levelled (except where partially sheltered) in one of these squalls as if 

 by the wand of a magician ; and trees which had stood two hundred years were torn 

 up by the roots. Dense clouds of dust always precede the rain and darken the air; 

 and it is amidst this imposing gloom that the lightnings flash with fatal eff'ect. 



The principal period of the year in which the wind is marked by its force, is in the 

 latter end of March, all April, and part of May. During these months it is mostly 

 a fresh west, sometimes strong ; and I find by a reference to my registers that there 



