yards or more into the coal-yard, and dashing with the utmost fury
against the cliff carried away , a balcony, which but half-an-hour
before had been vacated by thirty or forty spectators. The whole
.scene is described as one of wild and awful grandeur ; the sea and
•the shore being everywhere covered with broken boats, spars,
casks, timber, all floating in one huge boiling surge. The glacis
and the lines of Jamestown were impassable through wreck of every
description scattered about : coal-yards, wharf, and sea walls, batteries
and cannon, were swept down. At six o’clock in the evening
no abatement occurred, and two other ships, the Quatro de Marco,
which hitherto,, held by four anchors, had withstood the fury
•of the sea, and the Julia, a Brazilian, were dashed to pieces on
the west rocks. The destruction of these ships was as instantaneous
as a child would crush a fragile to y .. The former vessel was seen
with masts standing, only a moment before she floated a thousand
pieces in the surge. The latter was rolled over just as if
the waves were playing at football or cricket with her, and eventually
lodged high up on the west rocks against the cliffs of Ladder Hilt
At Rupert’s Valley the sea rolled inland a distance of 216 feet.
Eleven ot the destroyed ships were condemned slavers, and of no
great vaiue ; therefore the estimated damage done did not exceed
.10,000/. This oceanic phenomenon occurs with greater force and
more frequency at the Island of Ascension, in lat. 7° 58J' S., and
long. 14° 23J' W., where communication between ships and the
shore is completely stopped for a week or more at a time.
Through the kindness of Captain Wilmshurst, R.N., I was able
during the year commencing September, 1867, to make a comparison
of the time and force of the rollers at each Island.* I t
appears that they set in at Ascension, upon the average, one to
seven days sooner than they do at St. Helena, and that their course
is south or south-easterly from the Equator, breaking against the
northern shores only of both Islands. Although they happen at any
period of the year, they appear chiefly in the months of December
to March, usually occurring with greatest force in February, f
* Appendix, p. 404.
t Extracts from MSS. Island Records —
“ 16 Jany. 17|».—The Governor reports that the high seas which began the 13th
of this Instant and continued the 14th and 15th, has done a great deale of damage, it
has mtirely washed away the lower fort of two guns at ‘ Bankses,’ and had like to wash the
Popular opinion has ascribed the cause of the Rollers to distant
submarine volcanic action, but they occur with too much
regularity to admit this reason, and I believe them to be due
to oceanic currents, influenced by atmospheric pressure; in fact,
a return wave, caused by the meeting of the Antarctic waters
with the great Equatorial current of the Gulf Stream, and influenced
by the UST orth-east Trade winds. I t is during the Roller
months that the sun has greatest power in the Tropical Southern
Hemisphere, and therefore the greatest amount of evaporation takes
place ; consequently the flow of cold water from the Antarctic regions
towards the Equator is then most abundant and most rapid; as this
current gets well warmed by the time it approaches the Line, it is
hotter than the water of the great Equatorial current flowing south
round Cape Verde, which it meets in latitude 4° South. These
waters coming into violent collision, and not readily mixing because
of difference in temperature, must result in a return current either
northward or southward. This return takes place in the latter
direction, after the Equatorial current has been forced to flow out
,on either side against the Brazilian and the African continental
coasts.* The Equatorial current being at its maximum of strength at
this period of the year is to a great extent due to the influence of the
North-east Trade winds upon it, for it is their period of greatest force
and most southern latitude. During the months of December to May
the Equatorial limit of the North-east Trades is 5° to 7°N. la:., Lxgurs
away, for we had enough to do to save them. The same high seas has also broke the
middle angle of the Trench in James Valley for a matter of one hundred and ten foot, and has
damaged the angle where the round tower is of one gun insomuch as it was like to tumble
down.—These high seas sunk the punt and broke her loose, also the yaul, and nearly washed
down the crane.”
“ 6 April, 1715.—We think that a ship that arrives here about Christmas cannot possibly
be dispatched m less than a month, because of the very great surfes that usually happens
about that time of the year. We are informed that the latter end of March and beginning of
April is also a time when abundance of high seas do usually happen, and we are the more
confirm’d in such an opinion because the Honble: Companies long boat w“11 brought cutt stone
from Sandy Bay, w1* is at the Windermost part of the Island, has been laden these nine davs
and is still loaden at a grapling in this road, but the surf is so high and violent that we daré
not attempt to unload her, neither with these seas is it possible that any boat with safety can
come to the crane to be unlivered.”
'■IS» April, 1715.—This being the first day the Surfe abated the long boat was dispatched
again for Sandy Bay, and the Governor mencond it that it might appear what great
seas we have sometimes, but especially at this time of year, for now the' great seas have held
nmeteen days, and the long boat was unloaden with much difficulty by smaller boats.”
Boilers are also referred to as having occurred in March, 1717; December 1733 • February,
1720; and April, 1743.j ’ ’
* Maury, Phys. Geo. of the Sea, p. 383, § 892.