32 PHILOSOPHICAL TRANSACTIONS. [ANNO 17Q6. 



increased their alarm. Thunder and lightning had been observed some days before; 

 and several persons, of a delicate state of ^health, passed the night of the 1 8th in 

 a restless uneasy manner, without knowing why, though very much in the manner 

 in which they used to be affected by thunder and lightning." 



In Derbyshire the shock appears to have been very severe. A description of its 

 effects, not only on the earth, but also under its surface, is contained in the two 

 following letters from Mr. Wm. Milnes, of Ashover: the first is dated Nov. 20. 

 " On Wednesday night, about a quarter past 1 1 o'clock, a severe shock of an earth- 

 quake was felt here. I felt it very sensibly ; at first I heard a rumbling kind of 

 noise, and immediately after it appeared as if some persons had violently forced into 

 the room; the bed, and every thing else, shaking very much. The workmen in 

 Gregory mine were so much alarmed by the noise, and the sudden gust of wind 

 that attended it, as to leave their work; some expecting that the whole mass of 

 bunnings above them, which contains many hundred tons weight of rubbish, had 

 given way, and that they should be buried in the ruins; others, who were at work 

 near the new shaft, supposed that the curb which supports the walling had given 

 way, and the whole shaft had run in. Several chimnies were thrown down, and 

 several families left their habitations; indeed such a general alarm was never known 

 in this neighbourhood." 



The gust of wind mentioned by Mr. Milnes being considered as a remarkable 

 circumstance, he was desired to make some further inquiry concerning it: in con- 

 sequence of which a second letter was received from him, dated Dec. 4, as follows. 

 " I have examined all our miners separately, and, from the following circumstances, 

 I think there cannot be a doubt but the wind which was felt in the mines, on the 

 ] 8th of last month, rushed into the shafts from the surface. Those men who were 

 at work in the pumps, which are a considerable depth below the waggon gates, and 

 have no communication with thern, did not feel the wind; but heard in the first 

 place, a rushing rumbling kind of noise, which appeared to be at a distance, and 

 to come nearer and nearer, till it seemed to pass over them, and die away, Those 

 who were in the waggon gate which has a communication with the engine shaft, 

 and the new shaft, felt a very strong current of wind: which, one man says, con- 

 tinued while he walked about 6 or 7 yards, and came along the gate, as if it came 

 from the new shaft ; he had no light, but, as he went along the gate, its sides, 

 where he laid his hands, felt as if they were going to close in upon him. 



" The only one who saw any appearance of light, on that evening, in this 

 neighbourhood, was a person who lives with Mr. Enoch Stevenson, the miller, at 

 Mill Town, He informs me that, as he and another man were returning from 

 Tideswell, he saw, when he got on a piece of high land near Moor-hall, on the 

 road to Chatsworth, an uncommon light; and, when looking towards Chesterfield, 

 the sky appeared to be open for about the length of a mile, the colour pale red, 

 and continued so while he awakened his fellow servant, who was asleep in the 



