1849.] Seventeenth Memoir on the Law of Storms. 23 



It is at all times an invidious task to expose professional errors, but it is one 

 essential to the interests of science, of humanity, and of the public service, when 

 these involve not only great and useless pecuniary loss, but imminent risk of 

 life and property, and possibly great detriment, amounting even to partial failure, 

 of warlike operations. Such errors are moreover by so much the more mis- 

 chievous when they are committed in the face of knowledge now within every 

 seaman's reach, and in a quarter of the globe where, so to speak, the storms 

 have been tracked with mathematical accuracy through a long series of years 

 from 1780 down to the present time.* The very newspapers in China refer at 

 once to the Law of Storms to explain their tyfoons whenever they occur ! 



But I deem it my duty, Sir, to point out, what cannot have escaped you, that 

 the H. C. Steamer Pluto on this occasion steamed as wilfully into the heart of a 

 Tyfoon as if she had been sent out to experiment upon them ; and that heaving 

 to for six hours, or making a curve in her course not amounting to 100 miles of 

 direct loss on her track, would have fully and completely saved her and the 

 Government from all the loss and danger she has suffered, and left her services 

 available with the Admiral. 



I proceed to shew for the information of Government, by whom I trust this 

 letter may be forwarded to the Admiral, how this has been done. 



My documents are : — 



a. Log of the Pluto as forwarded by you, which is however imperfect, for 

 it is a copy of the remarks mostly ; the courses and distances steamed and 

 the winds, being omitted ! (the detailed log was however subsequently forward- 

 ed by Admiral Parker.) 



b. Private log of the chief officer of that ship forwarded to me by Capt, 

 Johnson. 



c. The Newspaper accounts from China, giving imperfect logs of the Brig Siewa, 

 and of the Nemesis and Pluto Steamers with reference to that of the Jane. 



d. The log of the Brig Anonyrna obtained here by myself. 



1. It appears that the Pluto left Hong Kong on the morning of the 27th June, 

 and at noon on the 28th was (at A on the annexed Chart)f in Lat. 19° 49' N. ; 

 Long. 113° 45' East. Her Barometer, which was at noon 30.00, had fallen by 

 6 m. p. to 29.90, and by midnight to 29.68, that is, it fell one-tenth in six hours 

 from noon, and something more than two-tenths more in the next six hours ; and 

 this was in the China Sea, in the tyfoon months, with the wind from the East- 

 ward, or against the usual monsoon, and with as much of other appearances as 

 rendered it quite a sufficient warning. 



* See " Storms of the China Sea from 1780 to 1841," by me. (Journal Asiatic 

 Society, vol. xi.) 



t See Chart to the present Memoir, on which, to the left, this sketch chart is 

 placed. 



