1]8 PHILOSOPHICAL TRANSACTIONS. [anNO 1750. 



It was particularly remarked (as before mentioned), that birds in cages were 

 sensibly afirighted, thrusting their heads under their wings. Mrs. Allicock, of 

 Loddington, a lady in childbed, was so aiFected that it caused her death. Some 

 people felt such a sudden shortness of breath, that they were forced to go out 

 into the open air, it so affected the pulmonary nerves. Many were taken with 

 head-achs. 



These are, in general, the observations made at the time of these earthquakes. 

 Give me leave now to make the following remarks. 



1 . As far as we can possibly learn, where no one can be prepared at different 

 places by time-keepers, this mighty concussion was felt precisely at the same 

 instant of time, being about half an hour after 12 at noon. This, I pre- 

 sume, cannot be accounted for by any natural power, but that of an electrical 

 vibration ; which we know acts instantaneously. 



2. Let us reflect on the vast extent of this trembling, 100 miles in length, 40 

 in breadth, which amounts to 4000 square miles in surface. That this should be 

 put into such an agitation in one moment, is such a prodigy, as we should never 

 believe, or conceive, did we not know it to be a fact, from our own senses. But 

 if we seek for a solution of it, we cannot think any natural power is equal to it, 

 but that of electricity ; which acknowledges no sensible transition of time, no 

 bounds. 



3. We observe, the vulgar solution of subterraneous eruptions receives no 

 countenance from all that was seen or felt during these earthquakes : it would 

 be very hard to imagine how any such thing could so suddenly and instanta- 

 neously operate through this vast space, and that in so similar and tender a man- 

 ner, over the whole, through so great a variety as well as extent of country, as 

 to do no mischief. 



A philosophical inquirer in Northamptonshire, who had his eye particularly 

 on this point, takes notice there were not any fissures in the ground, any sul- 

 phureous smells, or eruptions, any where perceived, so as to favour internal 

 convulsions of the earth ; yet we learn, from a letter, at Uppingham in Rut- 

 land, that a plaster floor became cracked thereby. These kind of floors are fre- 

 quent in this country : what we call stucco in London ; and it gives us a good 

 notion of the undulatory vibration produced by an earthquake ; which some have 

 compared to that of a musical string ; others, to that of a dog, or a horse, shak- 

 ing themselves when they come out of the water. 



4. The former earthquake, that happened at Grantham, Spalding, Stamford 

 (which towns lie in a triangle) took up a space which may in gross be accounted 

 a circle of 20 miles in diameter ; the centre of which is that great morass called 

 Deeping-Fen. This comprehends 14 miles of that 20 in diameter; and where, 

 probably, the electrical impression was first made. Much the major part of 



