ON NEW ENGLAND EARTHQUAKES. 11 



and quiet. Thus ended this great shock. It was followed by another about an hour and 

 a quarter after, viz., at 5'' 29'. This, though comparatively small, was very generally 

 perceived, both as to its noise and trembling, by those who were awake. On the Satur- 

 day evenuig following {November 22), at twenty-seven minutes after eight, there was a 

 third, more considerable than the second, but not to be compared with the first. And on 

 Friday, December 19, in the evening exactly at ten o'clock, there was a fourth shock, 

 much smaller than either of the former, though like them, preceded by the peculiar noise 

 of an earthquake. The whole lasted but a few seconds ; but the jarring was great enough 

 to cause the window shutters and door of the I'oom in which I then was, to clatter. The 

 sky was perfectly clear. * * * These four are the only shocks that 1 have been sensible 

 of, from the eighteenth of November last, to this date {January 10, 1756) ; though 

 more are said to have been felt in other parts of the country to the northward of us." 

 On the day of the first shock, nine hours after it was felt at Cambridge, or about two 

 o'clock in the .afternoon, the sea withdrew from the harbor of St. Martin's in the West 

 Indies, leaving vessels dry, and fish on banks where the depth of water was usually three 

 or four fothoms. It would seem from this, and from the observation of the direction of 

 the sound, that the earthquake vibrated from northwest to southeast, and of course its 

 secondary impulses were transverse to this primary line. As it moved much slower than 

 sound, as was shown by the fact that it was heard nearly a minute before the motion 

 was felt, it would not be unreasonable to suppose that as sound would require two 

 hours and a quarter to go such a distance, the earthquake wave impeded by ocean cur- 

 rents, may have required nine hours to send its secondary waves to the harbor of St. 

 Mai'tin's. 



How far did the shock extend ? Professor Winthrop says : ^ " By the best information 

 that I can procure, the limit toward the southwest was Chesapeake Bay. in Maryland, the 

 shock having been felt on the eastern side of that bay and not on the western. For the 

 other limit towards the northeast, we are informed that the earthquake was felt at An- 

 napolis Royal, in Nova Scotia, though in a much less degree than with us. It shook off a 

 few bricks from the tops of some chimneys, but was not perceived by vessels on the 

 water." It was not felt north of Halilax, but the army at Lake George perceived a slight 

 trembling ; and in the Atlantic, seventy leagues to the east of Cape Ann, the people on 

 board a vessel supposed they had run agrovmd, so \nolent was the shock, but their lead 

 showed fifty fathoms of water. If we consider the tidal wave at the West Indies a result 

 as well as a consequent of this New England shock, we shall have a line nearly nineteen 

 hundred miles long, and the shortest diameter of the shaken region would be almost five 

 hundred miles, but the intensity of vibration rapidly diminished away from the central 

 line. 



If all previously recorded earthquakes in New England were unimportant, and sent, as 

 Morton says, for " gentle warnings unto us to shake us out of our earthly-mindedness, 

 spiritual security and other sins, lest the Lord do come against us with judgment of this 

 kind in the sorest and worst sort of them," that of 1755 was one of great severity. In 

 Boston, the damage done was considerable, as is shown hy Professor W^inthrop.^ " Besides 

 the throwing down of glass, pewter, and other movables in the houses, many chimneys 



1 Loc. cit. p. 9. 2 Loc. cit. p. 11. 



