f . 



d4 PHILOSOPHICAL TRANSACTIONS. [aNNO 1757. 



length of time greater than what seems necessary for this effect. The earth- 

 quake itself, at the rate it moved with us, would be some hours in going from 

 hence to the distance of St. Martin's: for sound would be about 2^^ in moving 

 to such a distance ; and the progress of the earthquake was slower than that of 

 sound, as appears from hence, that the roar of this earthquake arrived here near 

 a minute before the shake. The rest of the g^ might well be spent in convey- 

 ing the motion excited in the water, from the place where it was excited to St. 

 Martin's ; for the waves raised by it could not move with near the velocity of 

 sound. 



It is worthy of remark, that of the 5 great earthquakes, which this country 

 has felt since its settlement by the English, 2 have gone nearly in the same track 

 as this last did. The first, which was on June 2, l638, " came from the north- 

 ward, and passed southward." By the description given of it, it was very much 

 like our late earthquake, only perhaps not quite so violent. " The noise and 

 shakes of the earthquake, October 29, 17 27, seemed," it is said, "to come from 

 the north-westward, and to go off south-easterly ; and so the houses seemed to 

 reel." As to the great earthquakes of l638 and 1662, we have no account of 

 the courses which they went in. But from the other three, it may be reasonably 

 conjectured that the source of our earthquakes, or the place in which they origi- 

 nate, is in some part of Canada, or perhaps beyond it. 



The extent of this earthquake seems to have been greater than that of any 

 in this country. The province of the Massachusetts-bay, or rather the province 

 of New Hampshire, about the latitude of 43° north on the sea-coast, seems to 

 have been the centre of it, or the place of its greatest violence ; and the shake 

 to have been less considerable each way from hence towards the s.w. and n.e. 

 By the accounts we have from the s.w. the shock was less at New York than it 

 was with us ; and still less at Philadelphia, which is farther towards the s.w. By 

 the best information, the limit toward the s.w. was Chesap)eak-bay in Maryland, 

 the shock having been felt on the eastern side of that bay, and not on the west- 

 em. For the other limit toward the n. e. we are informed, that the earthquake 

 was felt at Annapolis 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. And a letter from Halifax says, " The earth- 

 quake, which happened in the w. extended itself to this place, though scarcely- 

 perceivable here." But it was not at all felt by our army, which lay encamped at 

 Seganecto, about 100 miles n. from Halifax. Thus Halifax seems to have been 

 very near the n.e. limit. I am not able to ascertain its eastern and western 

 limits ; but it extended to all our back inland settlements ; and was perceived, 

 though in a very small degree, by our army at Lake George, distant from hence 

 about 130 miles n.vv. by w. But it was not felt at all at the British fort of 



