Raleigh's Tijfoon of 1835. 215 



3. That it was a progressive whirlwind storm ; turning to the 

 left, around its axis of rotation. 



4. That its centre of rotation passed to the northward of the 

 Lady Hayes ; and to the southioard of the Raleigh and of Canton, 

 and the anchorages near Macao ; and nearly on the hne A, B, C, 

 as marked on our chart. 



.5. That the rate of its progress was about seventeen nautical 

 miles per hour. 



6. That the extent or diameter of the violent part of the gale, 

 as deduced from its duration and rate of progress, was about four 

 hundred nautical miles, or equal to six or seven degrees of latitude. 



7. That the latter induction agrees with the geographical evi- 

 dence which has been obtained of the visitation of the storm. 



The progress of the tyfoon being taken at 17 miles per hour, 

 it follows that the excess of velocity of the wind at K with the 

 Raleigh, over that of the wind at W. with the Lady Hayes, sup- 

 posing the rotation to have been 'in a circle, would be more than 

 thirty miles an hour ; allowing nothing, however, for difference 

 of retardation of the surface wind, and not taking into the account 

 the additional retardation which the west wind of the Lady Hayes 

 must have been subject to, in its recurving course over the land. 

 If a circle be drawn on the chart around each of the points B and 

 C, with a radius equal to 3 or 3^ degrees of latitude, these circles 

 will comprise, somewhat nearly, the field of action of the storm, 

 at the two periods of 9 a. m. of the 5th, and 2 a. m. on the 6th of 

 August. 



The progressive velocity and course of this tyfoon, is nearly 

 the same as that of the' Trinidad hurricane of June, 1831 ; and 

 the rate of progression also corresponds nearly to that of the An- 

 tigua hunicane of August 12th, 1835. See tracks Nos. I, and Y, 

 on my chart of the courses of hurricanes, in the April No. of the 

 Nautical Magazine, 1836.* 



This examination of the case before us, appears to show that 

 the direction of rotation, and the course of progression of this ty- 

 foon^ while crossing the China sea, agree with those of the hurri- 

 canes of the West Indies ; and that its course ivas not controlled., 

 or matei'ially ijiflucnced, by the existing southwest mo7isoon. 



*For this chart, see also Silliman's Journal, Vol. XXXI, or Reid on the Law 

 of Storms, Chart III. 



