82 Voyage of the Novara. 



In these waters, and in a still more marked degree in the 

 latitude of Sumatra, occurs a belt within which the wave- 

 currents form what is known to English navigators as '' The 

 Ripples." The sea here is ranged zone-fashion, so to speak, 

 as though in fact in a state of ebullition, and makes a con- 

 siderable noise, yet without there being anything to indicate 

 an increased strength of current ; since, on the contrary, we 

 found when reaching these tracts, that the velocity of current 

 was if anything rather diminished. We conceive this phe- 

 nomenon may be attributed to the agitation caused by partial 

 tidal currents, crossing each others' course, and occasionally 

 even running counter to each other, as also to certain special 

 conditions of ocean temperature at varying depths. The 

 changes of the tides at points of the coast, proportionally 

 speaking so near each other, are so widely different in point 

 of time, and the height reached by the waves is so little 

 uniform, that any such phenomenon as the above must natur- 

 ally make itself perceptible at the surface in the open sea. 



While the change of tide at Kar-Nicobar takes place every 

 9h. 40m., that of Cape Diamond in Sumatra is laid down 

 in the English chart at 12h., and on the sandbanks in the 

 Straits of Malacca at only 51i. 30m. The difference in 

 elevation assigned exhibits a similar discrepancy in the esti- 

 mates ; that for Kar-Nicobar being stated at five feet, that for 

 Cape Diamond at 10 foet, and on the sandbanks already 

 mentioned at 15 feet. The hurricanes of the Bay of Bengal 

 never visit the Nicobars ; they seem to originate part in or 



