Earthquake at sea

Eleanor Reid's diary continues with a description of a very strange occurrence ...

We had the finest weather down the bay; the Nonsuch left us about latitude 16, and the Santa Cruz about latitude 10 north, leaving our squadron of four ships to take care of themselves, the Minerva being appointed commodore. 

We crossed the equator on the 28^th December, without meeting any of those distressing calms so prevalent between the Brazil and Gunea coasts. 

Nothing occurred worth noticing until the 6^th of January 1801, when about 11 P.M. the greatest panic seized all on board. We were alarmed by a grinding of the ship’s bottom, as if she had struck on a coralbank, attended with a rumbling noise, and most violent tremulous motion of the vessel. 

The captain instantly ordered the lead to be thrown out, but no bottom could be found with a hundred fathoms of line; the pump was then tried, to see if the ship were leaky in consequence of the shock, but she was found as tight as ever. There was a fine light breeze at the time, an the night not so dark but that the other three ships could be seen at no great distance; we ere in about nine degrees south latitude, and 92 east longitude, and upwards of five hundred miles from any known land. 

We were left to conjecture concerning this singular occurrence, but most of those on board concluded it must have been occasioned by an earthquake. Capt. R— gave the best description of the sensation by which he was awakened: he compared the agitation of the ship to that which would be experienced if a number of anchors were dropped from different parts of her at the same instant, and the noise to that which the cables would make in running out. 

When we compared notes with the other ships, we found they had been alarmed in the same manner; indeed one of them had guns ready to make signals of danger. There can be no doubt that it was caused by some convulsion at the bottom near where the ship passed.