S- 'Account of some remarlmUe Ripples 
in an extraordinary manner. Some of them not only dashed 
the water many feet up the side, but actually shook the ship in 
a very sensible degree. 
As we approached the line joining the north end of Sumatra 
and the Nicobar Islands, the ripples became more frequent and 
more violent. During the 5th of September, one passed the ship 
about every quarter of an hour. The wind at this time was 
between north-east and east, very light and variable, and some- 
times calm ; which rendered the effect of these ripples during the 
stillness of the night not a little striking. At first, a low hollow 
sound was heard, like that caused by a surf on a distant coast : 
it gradually became louder and louder ; till at length a long 
foaming streak was discovered advanemg rapidly towards the ship, 
which it soon surrounded, and then all was noise and commo- 
tion. This lasted for a few minutes, when the ripple moved 
past to the north-east, its sound becoming fainter and fainter ; 
and it often occun*ed, that just as one ceased to be heard, ano- 
ther was perceived, and so on during aU the night. Notwith- 
standing our distance from the shore, it was impossible to be 
without some alarm at first, when thus completely surround- 
ed by breakers, habitually associated in the minds of sailors 
with the most formidable of all dangers. 
During one evening the following curious phenomenon was 
observed. Whenever the ship entered one of the ripples, the 
wind immediately freshened, and at the same time changed its 
apparent direction ; but, upon quitting the ripple, the wind in- 
variably resumed its original velocity and direction. 
Before suggesting any theory to account for this circum- 
stance, it is right to state the facts precisely. The wind, which 
was very light, was blowing from north-east by north, (nearly 
N. 34° E.) The ship'^s head was west south-west, (W. 22 J S.), so 
that her course formed with the wind an angle of 146°. The rate 
of sailing was one mile and a half in the hour. When the ship 
entered the ripple, the wind invariably changed to north ; or, to 
speak more correctly, the vane, which before stood north-east 
by north, was now turned to north, so as to form an angle of 
only 112° with the course. At the same moment, an obvious 
increase in the strength of the wind took place. On getting in- 
to smooth water again, the vane returned to north-east by 
north, and the wind instantly lulled. 
