Appendix D. 491 



The minimum pressure according to the curve would be 28.975, but 

 must actually have been less. According to the strict reading it would 

 result that all radii before reaching the point where nearest the central 

 path, as also all those in the same half-circle after such central line has 

 been crossed, should have the same value, whatever the direction, which 

 if rigidly asserted cannot be correct, since the motion of a cyclone is 

 truly circular only in the immediate vicinity of its central point. As that 

 point is receded from, the motion becomes more or less elliptical, as is 

 attested by the barometric differences, which had the cyclone been a true 

 circle in all its parts ought to be similar for similar distances. This it 

 is admitted is not the case, as the barometric pressure shows a marked 

 decline in the earlier part of a cyclone the more rapidl}^ the central line 

 is approached, just as it rises again once that line has been passed. 



For this reason the distances as assigned upon a line of curves deduced 

 from the foregoing observations must be too great, especially those which 

 are calculated at right angles to the path of the typhoon, because per- 

 pendiculars drawn at right angles to the varying directions of the wind 

 must intersect each other at points more distant than the actual central 

 point of the cyclone itself. 



To the foregoing may be appended a few extracts recounting the dam- 

 age done by the great typhoon of 27th July, 1862, from which some idea 

 may be formed of the tremendous violence and destructive effects of this 

 description of atmospheric agency. 



From London and Cliina Telegraph, 2Qt1i Sept., 1862. 



"A dreadful typhoon occurred at Canton on 27th July, 1862. The 

 destruction of life and property is immense, the loss of life in the city 

 and neighbourhood being estimated at about forty thousand. In the 

 telegram which was received a few days ago announcing this event, a 

 query was placed, and very reasonably, after the number stated ; but the 

 press state that as far as inquiries have been made at present it is 

 probably correct. The loss of life has chiefly occurred amongst the junk 

 population, and the fine new fleet of forty Imperial junks, intended for 

 the Yang-tse-kiang, has been destroyed. The water rose till the streets 

 of Ilonam had three feet in them, but the buildings suffered less than 

 might have been expected ; some two or three hundred feet of the granite 



