in this country; what we call ſtucco in London: arid it gives us a good notion of the undulatory vibration, produc‘’d by an earthquake; which ſome have compared to that of a muſical ſtring: others to that of a dog, or a horſe ſhaking themſelves, when they come out of the water. This laſt compariſon would have pleaſed ſome of the ancients, who would needs fancy, that the globe of the earth was a great animal. Plato, Plutarch, and others, had ſuch kind of ſentiments. Whence one may imagine, that they would conceive an earthquake to be, as when a horſe ſhakes a part of his skin, upon a fly touching him. Some of our correſpondents expreſs the motion of an earthquake to be like a boat lifted up by one wave, let down by another.
4ly, The former earthquake that happen’d at Grantham, Spalding, Stamford, (which towns lie in a triangle) took up a ſpace which may, in groſs, be accounted a circle of 30 miles diameter: the center of which is that great moraſs, called Deeping-fen. This comprehends 15 miles of that 30, in diameter: and where probably, the electrical impreſſion was firſt made. Much the major part of Deeping-fen is under water in the winter time; underneath ’t is a perfect bog. Now it is very obvious, how little favorable ſuch ground is, for ſubterraneous fires.
