VOL. LXXXVI.] PHILOSOPHICAL TRANSACTIONS. 31 



sizes ; it is not perfectly globular, being flattened a little on two opposite sides, 

 which appear to have been the poles when in a revolting state ; and each ball is 

 more or less furrowed in a latitudinal direction, as if, when revolving round its 

 axis, and taking its fixed state from a more fluid one, it had met with some resist- 

 ing substance. 



Though the surface of this country is very rocky, it does not discover lime-stone 

 any where within 20 miles of this tunnel ; yet if the strata near the lime-stone at 

 Buxton to the south, and at Clitheroe to the north, are examined, it will appear 

 probable that the base of these hills is lime-stone at some depth, and this fault dis- 

 covered in the shale probably extends from the lime-stone bed beneath ; and the rib 

 of lime-stone and balls which, with other mixed substances, fill up this crevice or 

 fault, were probably thrown thither from the mass beneath, by the volcanic erup- 

 tion which first occasioned this break in the strata, or by some subsequent eruption 

 of the same kind. 



XV. Account of the Earthquake felt in Various Parts of England, Nov. 18, 1795. 

 By Edw. Whitaher Gray, M. D., F.R.S. p. 353. 



This earthquake happened about 1 1 o'clock at night, of the day above-mentioned. 

 It appears that the shock was felt as far to the north as Leeds, and as far to the 

 south as Bristol. To the east it was felt as far as Norwich, and to the west as far 

 as Liverpool. Its extent from north to south therefore was about 105 miles; and 

 its extent from east to west about 175. In this latter direction, or rather from 

 north-east to south-west, it may be said to have reached nearly across the island. 

 The counties in which it has been perceived are, Somerset, Wilts, Oxfordshire, 

 Buckinghamshire, Northamptonshire, Huntingdonshire, Norfolk, Lincolnshire, 

 Leicestershire, Warwickshire, Gloucestershire, Herefordshire, Worcestershire, 

 Staffordshire, Cheshire, Derbyshire, Nottinghamshire, Yorkshire, and Lancashire. 

 To which may probably be added the counties of Rutland, Berks, Bedford, Cam- 

 bridge, and Shropshire. I have not indeed met with any account of the earthquake 

 from either of them; but, whoever will examine the situation of these counties, 

 with respect to those above enumerated, will find it difficult to conceive that they 

 were not, in some degree, affected by it. 



The accounts of it from different places are nearly alike: the duration about 2 

 seconds. From Worcester the following account of it was sent by Dr. Johnstone 

 of that city, in a letter dated Nov. 24 ; which may be considered a pretty good 

 specimen of the several accounts. " The earthquake was chiefly felt by persons in 

 bed, about 1 1 o'clock, or 5 minutes after, who describe the sensation to have been 

 as if some person under the bed had heaved it up. That sensation was preceded, 

 the instant before, by a noise which some call rumbling, and which others compare 

 to the falling of tiles, though none fell from the houses where they lived. Many 

 persons heard the windows and doors of their rooms rattle at the same time, which 



