tending as far as 2° N. in February and March ; while for the rest of
the year they only reach as far as 10° 62' N.* Their proportionate
force is also during the same periods, between the parallels of 10° to
15° N. lat., as 7‘41 to 4-83.j-
Some idea of the enormous force with which these waters meet
and send back the Anctarctic current against the shores of Ascension
and St. Helena, may be obtained from the following extract from
Admiral Semmes’ Voyages —
“ For the next few days, we encountered a remarkable easterly
current, the current in this part of the ocean being almost constantly
to the westward. This current, which we were now stemming—for
we were sailing towards the north-west—retarded us as much as fifty
miles in a single day! So remarkable did the phenomenon appear,
that if I had noticed it but for a single day I should have been inclined
to think that I had made some mistake in my observations,
or that there was some error in my instrument; but we noticed it
day after day for four or five days.
“ Contemporaneously with this phenomenon, another and even
more wonderful one appeared. This was a succession of tide-rips,
so remarkable that they deserve special description.
“ The Sumter lay nearly stationary during the whole of these
phenomena, the easterly current setting her back nearly as much as
she gained under sail. She was in the average latitude of 5° N.,
and average longitude of .42° W. For the first three days, the rips
appeared with wonderful regularity, there being an interval of just
twelve hours between them. They approached us from the south,
and travelled towards the north. At first only a line of foam-would
be seen on the distant horizon, approaching the ship very rapidly.
As it came nearer, an almost perpendicular wall of water, extending
east and west as far as the eye could reach, would be seen, the top
of the wall hoiling and foaming like a breaker rolling over a
rocky bottom. As the ridge approached nearer and nearer, it
assumed the form of a series of rough billows, jostling against and
struggling with each other, producing a scene of the utmost confusion,
the noise resembling that of a distant cataract. Reaching the
ship, these billows would strike her with such force as to send their
* Horsburgh. f Maury.
£ My Adventures Afloat. By Admiral Semmes.
spray to the deck, and cause her to roll and pitch as though she were
amid breakers. The phenomenon was, indeed, that of breakers, only
the cause was not apparent, there being no shoal water to account
for it. The Sumter sometimes rolled so violently in these breakers
when broadside to, that we were obliged to keep her off her course
several points to bring the sea on her quarter, and thus mitigate the
effect. The belt of rips would not be broad, and as it travelled very
rapidly—fifteen or twenty miles the hour—the ship would not be
long within its influence. In the course of three-quarters of an hour
it would disappear entirely on the distant northern horizon. So
curious was the whole phenomenon, that the sailors as well as the
officers assembled, as if by common consent, to witness it. ‘ There
come the tide-rips!’ some would exclaim, and in a moment there
would be a demand for the telescopes, and a rush to the ship’s side
to witness the curious spectacle. These rips have frequently been
noticed by navigators, and discussed by philosophers, but hitherto no
satisfactory explanation has been given of them. They are like the
bores at the mouths of great rivers—as at the mouth of the Amazon,
in the Western Hemisphere, and of the Granges in the Eastern—great
breathings or convulsions of the sea, the causes of which elude our
research. These bores sometimes come in, in great perpendicular
walls, sweeping everything before them, and causing immense destruction
of life and property. I was at first inclined to attribute these
tide-rips to the lunar influence, as they appeared twice in the twenty-
four hours, like the tides, and each time near the passing of the
meridian by the moon; but, in a few days, they varied the times of
their appearance, and came on quite irregularly, sometimes with an
interval of five or six hours only. And then the tidal wave, for it
is evidently this, and not a current, should be from east to west, if
it were due to lunar influence; and we have seen that it travelled
from south to north. Nor could I connect it with the easterly current
that was prevailing, for it travelled at right angles to the current,
and not with or against it. I t was evidently due to some pretty
uniform law, as it always travelled in the same direction.”