_In the Tables of the Variation of the Magnetic Needle, Anno_ 1756, Lat. Long. 0--70E _for Var._ 3¼W _read_ 2¾W. _Read the same in p._ 333. 15N 35W ---- 3½W ---- 2½W 5S 40E ---- 17W ---- 18W 30S 15E ---- 18W ---- 17½W 35S 10W ---- 5½W ---- 5W 35S 45E ---- 26½W ---- 26W PHILOSOPHICAL TRANSACTIONS. I. _An Account of the Earthquake felt in_ New England, _and the neighbouring Parts of_ America, _on the 18th of_ November 1755. _In a Letter to_ Tho. Birch, _D.D. Secret. R.S. by Mr. Professor_ Winthrop, _of_ Cambridge _in_ New England. [Read Jan. 13, 1757.] Reverend Sir, I Beg leave to lay before you the best account I am able to give of the great earthquake, which shook New England, and the neighbouring parts of America, on Tuesday the 18th day of November 1755, about a quarter after four in the morning. I deferred writing till this time, in order to obtain the most distinct information of the several particulars relating to it, both here and in the other places where it was felt; and especially the extent of it. The night, in which this earthquake happened, was perfectly calm and serene. In the evening there was a fog over the marshes bordering on the river Charles, which runs through this town: but this I found intirely dissipated at the time of the earthquake, the air being then quite clear, and the moon, which wanted but 36ʰ of the full, shining very bright. The earthquake began with a roaring noise in the N.W. like thunder at a distance; and this grew fiercer, as the earthquake drew nearer; which was almost a minute in coming to this place, as near as I can collect from one of my neighbours, who was then on the road in this town. He tells me, that, as soon as he heard the noise, he stopt, knowing, that it was an earthquake, and waiting for it; and he reckoned he had stood still about 2’, when the noise seemed to overtake him, and the earth began to tremble under him: but, as I doubted, whether it were so long, I counted several numbers to him as slowly as a clock beats seconds; and then he said, he believed he could have counted half an hundred, at that rate, before the noise and shake came up to him. By his account, as well as that of others, the first motion of the earth was what may be called a pulse, or rather an undulation; and resembled (to use his own comparison) that of a long rolling, swelling sea; and the swell was so great, that he was obliged to run and catch hold of something, to prevent being thrown down. The tops of two trees close by him, one of which is 25, the other 30 feet high, he thinks waved at least ten feet (and I depend on his judgment in this particular, because he judged right of the height of the trees, as I found by actual mensuration); and there were two of these great wavings, succeeded by one, which was smaller. This sort of motion, after having continued, as has been conjectured, about a minute, abated