332 PHILOSOPHICAL TRANSACTIONS. [anNO 1778. 



moss or loose garden ground felt it heave under them very perceptibly ; and 

 others, who sat or lay on the ground, were so shocked as to be thrown forcibly 

 out of the position they were in. To Mr. H. and several others, who observed 

 the progress of this phenomenon coolly, 3 shocks were very clearly distinguish- 

 able. Some persons were sensible of 1, and some of l only. 



The motion of the earthquake, at least of a rushing wind which attended it, 

 was from south-west to north-east. It was felt at York, Lancaster, Liverpool, 

 Chester, Birmingham, Derby, and Gainsborough ; and within this circuit, the 

 diameter of which must be 130 or 140 miles, with greatest violence in this 

 neighbourhood, which appears to have been the centre of it. 



The morning on which the earthquake happened was clear and serene. The 

 air was so far from being sultry, that some persons who rode out early in the 

 morning complained of the cold. The wind was easterly. At the instant of 

 the shock it is said to have veered to the west, and to have immediately returned 

 to its former station. On the 20th, 21st, and lid of September much rain fell, 

 attended with thunder and lightning. The storm was particularly violent on the 

 21st in the neighbourhood of Rochdale, 12 miles from hence ; and early on the 

 morning of the 22d the whole hemisphere appeared, from this place, to be in- 

 volved in one general blaze. 



XF^. Sundry Papers relative to an Accideiit from Lightning at PurJIeet, May 



15, 1777. 

 1. ^ Letter from Mr . Boddington, Secretary to the Board of Ordnance, to Dr. 



Horsley, Sec. R. S. ivilh Two Enclosures from Mr. Nichson, Store-keeper at 



Purfleet, giving an Account of the Occident. 

 Sir, Office of Ordnance, MaySl, 1777. 



I am directed by the lieutenant-general and the rest of the principal officers of 

 the Ordnance, to transmit to you the copies of the reports and plan received 

 from Purfleet, on occasion of some damage done by lightning ; which reports 

 and plan they desire you will please to lay before the r. s. I am, &c. 

 To Dr. Horsley, Sec. R. S. John Boddington. 



•' ^ To Sir Charles Frederick, Knt. of the Bath. 

 Honourable Sir, Purfleet, May l6, 1777. 



Yesterday afternoon we had much rain and distant thunder ; but at 6 a very 

 heavy cloud, in passing over the house, presented us with part of its contents, 

 which struck the north-east corner of the house on one of the cramps that held 

 the copeing stones together, forced off about a square foot of that stone and one 

 brick, and has displaced about a cube foot of brick-work underneath. It has 

 not been yet discovered that any of the conductors have acted during the passage 

 of that cloud, though the flash and report were both very great. One of my 



