1845.] Fourteenth Memoir on the Law of Storms in India. 909 



we must take as the nearest approximation to the semi- diameter of the 

 (somewhat flattened?) vortex, or 116 miles for the diameter; which 

 agrees well with what we estimated it to be from the Caledonia s log. 

 We further see by Capt. Biden's note, the extract from the Colombo 

 Observer, and Mr. Higgs' valuable register, that while the centre was 

 passing over Baticolo at about half-past two in the morning, (the calm 

 focus there seems to have been quite small in extent,) it was blowing 

 from the East in " most violent gusts," at Trincomalee, which is about 

 sixty miles in a NNW. direction from Baticolo, which gives 120 miles 

 of diameter for it on shore. 



The Baticolo description remarks, indeed, that M the hurricane" did not 

 extend to the country about the South extremity of the lake, which 

 extends about twenty miles from the flag-stafF; but by this phrase, the 

 writer probably means that, although there was a gale, yet it was not as at 

 Baticolo, a hurricane, levelling every thing before it. Places situated to- 

 wards the Southern half of a Storm Circle, where it infringes upon 

 high land, and comes straight in from the sea, should also be partially shel- 

 tered ; while those on the Northern side (Trincomalee in this case), 

 should feel its full force ; because, if we follow the wind in its circuit, we 

 shall see that the outer zones of it to the North-west, must be im- 

 peded by the high land. A centre at Baticolo giving a strong gale at 

 Trincomalee, would extend sixty miles inland to the Westward, over a 

 perfectly flat country ; but the first mountain ranges of considerable 

 elevation, certainly approach within twenty-five or thirty miles of the 

 coast. I have endeavoured to mark this effect on the chart by the 

 Baticolo circle of wind- arrows, making them wavy and broken as they 

 skirt and turn off from the mountain ranges ; noting, however, that this 

 is merely to express my views of the probability of what took place. 



The calm at the Basses is also accounted for by their being so com- 

 pletely sheltered and by their distance from the centre. The gales at 

 Colombo are described as being, u brief though severe." They were 

 possibly streams of wind forcing their way through defiles of the moun- 

 tains ? for the vortex if it continued entire above, must have been much 

 divided and broken up below, and probably indeed " lifted up" by the 

 very high land in the interior of Ceylon. 



The Trincomalee report from Mr. Higgs requires some farther notice, 

 its barometrical register giving it especially a high value. We find that 



6 £ 



