656 PHILOSOPHICAL TRANSACTIONS. [anNO 1755. 



LIX, An Account of the Earthquake, Nov. 1, 1755, as fell in the Lead Mines 

 in Derbyshire. Bij the Rev. Mr. Bullock, p. SQS. 



The following is an account of the earthquake, which happened at the lead 

 mines on Eyam-edge in the peak of Derbyshire, on Saturday the 1st of Nov. 

 1755, about 11 o'clock in the forenoon. 



Francis Mason, the overseer, says, That he sat in a little room, about 40 

 yards from the mouth of one of the engine shafts. He felt one shock, which 

 very sensibly raised him up in his chair, and caused several pieces of lime or 

 plaster to drop from the sides of the room. In a field about 300 yards from the 

 mines, there had happened a chasm or cleft on the surface of the earth, which 

 was supposed to be made at the same time he felt the shock; its continuation 

 from one end to the other, was near 150 yards, being parallel to the range of the 

 vein on the north side: the depth of it was about 8 or 9 inches, and its dia- 

 meter 4. 



Two miners say, that at the aforesaid time they were employed in carting, or 

 drawing along the drifts the ore and other minerals to be raised up the shafts. 

 The drift where they were working, is about 60 fathoms, or 120 yards deep, and 

 the space of it from one end to the other upwards of 50 yards. They were 

 suddenly surprised by a shock, which greatly terrified them. They durst not at- 

 tempt to climb the shaft, lest that should be running in on them, but consulted 

 what means to take for their safety. While they were thinking of some place of 

 refuge, they were alarmed by a shock much more violent than the former ; which 

 put them in such a consternation, that they both ran precipitately to the other 

 end of the drift. Soon after they were again alarmed by a third shock; which, 

 after an interval of about 4 or 5 minutes, was succeeded by a fourth ; and about 

 the same space of time after, by a fifth ; none of which were so violent as the 

 second. They heard after every shock a loud rymbling in the bowels of the 

 earth, which continued for about half a minute, gradually decreasing, or appear- 

 ing at a greater distance. They imagined, that the whole space of time, from 

 the first shock to the last, was about 10 minutes. They remained about 10 mi- 

 nutes in the mine after the last shock; when they thought it advisable to exa- 

 mine the passages, and to get out of the mine, if possible. As they went along 

 the drifts, they observed, that several pieces of minerals had dropped from the 

 sides and roof, but all the shafts remained entire, without the least discomposure. 

 The space of ground at the mines, wherein it was felt, was 960 yards, being all 

 that was at that time in work. 



1. Account of the Earthquake at Lisbon,* Nov. 1, 1755, in Ttvo Letters from 



Mr. JVolfall, Surgeon, p. 402. 

 Since the beginning of the year 1750, we have had much less rain than has 

 • This city suffered greatly by an earthquake in 1531. — Orig. 



