VOL. XLIX.] PHILOSOPHICAL TRANSACTIONS. 66l 



dried up entirely, returned 2 days after to its usual state. In some places where 

 there was no water, springs burst forth, which continued to run. On the spot 

 of Varge, and river of Macaas, at the time of the earthquake, many springs of 

 water burst forth, and some spouted to the height of 25 palms,* throwing up 

 sand of various colours, which remained on the ground. On the hills, numbers 

 of rocks were split, and there were several rents in the ground, but none con- 

 siderable. On the coast pieces of rock fell, some of them very large, and in 

 the sea sundry rocks were broken : the most noted are those called by the sailors 

 Sarithoes, or Biturecras, of which one was only broken off at the summit, the 

 other all to pieces. 



Between these rocks and the main, the coasting vessels sailed at low water ; 

 and now you may go to them at low water, without wetting your feet. From 

 the rock called Pedra de Alvidrar, a kind of parapet was broke off, which issued 

 from its foundation in the sea. In a swamp or lake, which received a good deal 

 of water in winter, and was not dry in summer, the earth rose ; for there is now 

 scarcely the appearance of a hollow, which was before to the depth of six or 

 seven palms ; it now remains even with the adjacent ground. In other places, 

 by the change of the currents it appears that the earth was moved, so that some 

 spots are more elevated, others more depressed than before. 

 6. Concerning ihe Earthquake at Oporto in Portugal, Nov. 1, 1755. By a 



Letter Jrom that Place, p. 418. 



Saturday Nov. 1st, we had such a terrible earthquake here, that we were 

 afraid of being swallowed up alive, though it has done but very little damage. It 

 began about half an hour past Q o'clock in the morning, like thunder, or rather 

 the rattling of a coach over stones , and my own house, as well as most other 

 people's, during the first shock, which was a very terrible one indeed, was just 

 as if in a convulsion, which lasted 7 or 8 minutes, and every thing shook and 

 rattled in it all the time, as if it was coming down ; which frightened people so 

 much, that a great many ran into the streets, where I plainly saw the earth 

 heave up. At 6 o'clock at night there was another great shock. The river 

 also rose and fell surprizingly every quarter of an hour, for upwards of 4 hours 

 at least, 4 or 5 feet, and sometimes more ; and some saw the river in some 

 places open, and throw out a vast deal of wind, which was very terrifying. 

 Abstract of Two Letters to Mr. Plummer, Merchant in London, from Oporto, 

 concerning the Earlhquakefelt there, p. 419. 



This morning, Nov. 1, 1755, between 9 and 10 o'clock, this city was alarmed 

 with the terrible shock of an earthquake, which continued violently for 5 or 6 

 minutes, but has done no further damage than the overturning some pedestals 



* The Portuguese palm is about 9 inches. — Orig. 



