PHENOMENA AT SEA. J 



The effects proceeding from these dense clouds during These efFects 

 their passage over the zenith, are the opposite to those are opposite to 

 experienced from a regular squall ;— for this generally * ° asqua 

 first makes its appearance by a small arched cloud, either 

 rising from the horizon, or formed at a small distance 

 above it ; which rises gradually until near the zenith. 



When the preceding clouds of the arch approach the Effects of the 

 zenith, the strength of the squall commences, and conti- squ^H- 

 nues strong during the passage of the clouds over it ; 

 •which is the reverse of what has been noticed as the re- 

 sult proc(^eding from dense clouds generated at high alti- 

 tudes. — Currents or ripplings on the surface of the sea, Currents and 

 seem to have an affinity with the wind. — Where tides run '^^^^ ^^^^ the 

 strong, in the entrance of great rivers and other places, 

 the strength of the wind is often observed to be modified 

 by the tide ; blowing strong on the flood, and moderate 

 on the ebb, when the direction of the wind is into the ri- 

 vers, or nearly in the line of the f^od tide. 



The following peculiarity of a sudden variation in the Upon banks or 

 strength of the wind, has frequently been observed in low ?^^^ *^^ ^rad 

 latitudes. — In settled weather, when a brisk and regular considerably 

 wind is experienced in deep water, if there are any shoal less than on the 

 banks or coral flats of considerable extent, the strength *^^^P water, 

 of the wind is often perceived to be much less on these 

 banks or flats, than in the deep water ; mor« particularly 

 if eddies or ripplmgs, occasioned by tide or currents pre- 

 vail on the banks' at the time. — I have often observed in 

 getting on the edge of one of such banks, that the strength % 

 of the regular breeze instantly abated ; but resumed its 

 regular force on departing from the verge of the bank in- 

 to deep water ;— this has been experienced repeatedly ; 

 and I have found a ship hardly manageable from a defici- 

 ency of wind on the verge of a bank with shoal water on 

 it ; when at a small distance from it in deep water, some 

 of the light sails were obliged to be taken in, the regular 

 breeze over the surface of the deep water, prevailing so 

 strong. 



In several parts of the Indian Seas, particularly to the Very strong 

 eastward of the-Nicobar Islands, between xlchen Head ripphngs in the 

 and Junkseylon, very strong ripplings prevail during the Jempof^^^^^^^^ 

 south-west monsoon— When these ripplings are very minutioa of " 

 high and numerous, there is seldom any current experien- ^'''^* 



ced ; 



