1849.] Eighteenth Memoir on the Law of Storms. 905 



is generally considered to be an electrical pbsenomenon, and whether 



it be as a cause or an effect, every electric indication is of importance. 



The Storm Wave and Storm Current, and the set over the Sandheads, 



before and during the Cyclone* 



Taking the storm wave as our first subject of consideration, we find 

 it very clearly described to me by Mr. Brackly, (which I have substitut- 

 ed for his official report from False Point,) p. 849, in terms which leave 

 no manner of doubt that it was a peculiar effect of the Cyclone, and this 

 is more unquestionably shewn when we advert to the time of tide at 

 which it occurred. Had it occurred with the inset of the flood we 

 might have allowed it to have been a tidal bore so common in our 

 Indian rivers. 



The fact that it occurred about three hours after the passage of the 

 centre of the calm is at present difficult to account for. We can only 

 note it at present as an apparent anomaly, to be compared with other 

 correct accounts when we obtain them. 



But of the storm currents in the Bay, and especially of that setting 

 over the Sandheads, we have abundant proof for all practical purposes, 

 and we can in fact trace it more or less from the middle of the Bay 

 up to the Sandheads, then across them and again to the Southward, as 

 we shall now show from the different ships' logs and Pilots' reports. 



The Sea Park, which ship hove too, soon after the centre passed 

 her, on the eastern side of the Cyclone, with the wind South, notes 

 from the 12th at 4 p. m. to the 14th at noon, a set of 80 miles 

 to the Northward. This was between Lat. 18° and 19° J N. 



Captain Plum, of the John Hepburn, states that he experienced a 

 strong current to the Northward ; this was between \7\ and 19| N. 



But as these two vessels were hove too it might be fairly supposed 

 by strangers that they had under-estimated their drift, but we have the 

 log of the Collingwood, which ship was running up with the Cyclone 

 close on its S. Eastern quadrant, and though for a considerable time 

 within the Southerly current off Point Palmiras, yet she has an excess 

 of 31 miles by account to the North of her supposed position in 24 

 hours, partly no doubt from the storm wave, and partly from the storm 

 current.* 



* I am enabled to add here from an independent but very trustworthy source, a 

 remarkable instance of the storm current, in the case of the ship Albion, Captain 



