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hollows, are impregnated with sulphur and salt, where, being pent down and confined, they at last force a passage through the interstices which drain off the superficial water, and thereby occasion that pulsation in the flame, resembling a smith's forge.

I am farther confirmed in this supposition by the circumstances attending its last, and probably, its final cessation; for about three years ago a gentleman determined to sink a coal-pit near the spot, but the undertaking proved expensive, and hazardous; the workmen were greatly annoyed by wildfire, and when they had sunk to the depth of 88 yards, and began to get coals, a subterraneous reservoir of brine suddenly burst into the work, and filled it to the level of 18 yards, which proved to be only a stagnant lake, and not a brine spring, although it was so strong that an egg swam high in it. The pit was afterwards drained, but the sulphur remaining excessively strong, it was judged proper to fire it, which caused so terrible an explosion as alarmed all the neighbourhood, they imagining it had been an earthquake. It shook their windows, pewter, and even the casks in the cellars. This, however, seemed like a dying groan of the burning well, which since that time has entirely ceased to burn.

Had such a curiosity appeared near London, the discoverer would probably have got a fortune by it; but now we can only perpetuate its memory by inserting this account, which you may depend upon as authentic.

1755, July.

Yours, &c.

G. PERRY.

XVIII. Fire from the Bowels of a Beast.

THE latter end of October, 1751, an inhabitant of Esnans, near Neufchatel, in Franche-compté, who had a beast that had been sometime sick and extremely swoln, gave it about the quantity of an ordinary charge of gunpowder in cold water, upon which the swelling presently subsided; but it soon returning, the remedy was again repeated, but produced only a transitory effect. It was therefore resolved to kill the creature, and several of the neighbourhood came out of curiosity, at the opening of it, to see in what condition the flesh was. As a butcher was forcibly drawing out the stomach, or paunch, he tore it, and there instantly issued

forth, with some noise, a flame that rose above five feet high, which burnt his hair and eyebrows, and affected his eyes to that degree, that he could not bear the light for a long time. A young girl who held a lamp to light him, had all her hair burnt off, and would probably have been a further sufferer, had not her mother thrown her apron over her head, and so smothered the fire. This flame continued decreasing two or three minutes, the paunch contracting all the while, but an intolerable stench remained in the cowhouse.

As singular as this fact appears to be, it is not the only one we have upon record. Fortunius Licetus, in his book De lucernis antiquorum reconditis, reports, that a professor of anatomy at Pisa dissecting a body in the public amphitheatre, and a candle standing near him, there burst forth from the stomach a vapour which kindled at the candle. This accident appears to be near a-kin to that above related, and both seem to prove, that vapours easily inflammable may be formed in animal bodies, for it is very unlikely, that the gunpowder which the beast had swallowed several days before, could any ways contribute to such an event. 1755, Oct.

XIX. Earthquakes, how produced.

IN order to form the most probable system of earthquakes, it should be observed, that all readily inflammable substances, as gunpowder, and nitrous or sulphureous minerals, in their ignition generate a large quantity of air, and that the air thus produced is in a state of very extraordinary rarefaction, and if compressed within the bowels of the earth, cannot but occasion very violent effects. Suppose, therefore, that at the depth of 100 or 200 fathoms there be lodged pyrites, or other sulphureous matters, and that by the fermentation produced from the filtering of waters, or other causes, these happen to take fire, what will most likely be the result?

In the first place, it is known that those substances are not, for the most part, disposed in horizontal strata; on the contrary, they are contained in perpendicular fissures, and in caverns at their bottoms, as also in other places into which waters can penetrate. These substances coming to take fire upou imbibing water, will generate a large quantity of air,

spring of which, compressed in a little room, will not only shake the superior ground, but seek for passages whereby to extricate itself: such are the canals formed by subterraneous rivulets, where a furious wind will be formed, whose noise will be heard at the earth's surface; and this wind will throughout its whole extent cause an earthquake, more or less violent, in proportion as it is more or less remote from the new kindled fire, or rushes through passages more or less narrow. This explication seems to agree with the several phenomena of earthquakes.

Chemistry furnishes a method of making artificial earthquakes, whose effects are in all respects similar to those of the natural ones. As it fully illustrates the process of nature upon the very principles I have advanced, I here give it, though pretty well known, from Boerhaave.

To 20 pounds of iron filings, add as many of sulphur; temper, mix, and knead the whole with a little water into a stiff mass, which bury some feet deep in the ground. In six or seven hours, time this will produce a prodigious effect; for the earth will begin to tremble, crack, and sinoak, and actual fire and flame will at length burst through. Such is the effect of two cold bodies in the cold ground, from the bare intermixture of a little water: there wants but a sufficient quantity of the mass to produce a true volcano.

It has been observed for ages past, that places near the sea are the most exposed to the terrible disasters of earthquakes; on which account, doubtless, it was that Neptune was called by the ancients Σεισίχθων, as also Κινοσίχθων, Ενοσί ya and Thaxlopoyains, by all which epithets they denoted his power of shaking the earth. Cast your eyes to those parts of the globe where volcanoes most abound, and you will find them all situated in islands, or near the sea coast, and where these are, earthquakes are frequent. The Alps are not subject to them, but those parts of Italy which are farthest advanced into the Mediterranean are; and the like holds good in America.

The season of the year seems to have some share in these tremendous events. The first great overthrow of Lima was indeed in July 1586, but the other two, of 1687 and 1746, happened both in October, probably after the equinoctial high tides, in conjunction with the western winds, had introduced much water into the subterraneous cavities. Lima has been considerably shaken by two other earthquakes, in 1630 and 1655, both which, like the late dreadful one at Lisbon, were in November.

1755, Dec.

XX. Account of a moving Hill.

MR. URBAN,

GIVE me leave, by your means, to communicate to the public what seems highly to deserve their notice, and what you may depend on the truth of, having been myself an eye witness.

At a place called Toys Hill, about three miles from Westerham in Kent, about two acres and a half of ground (part ploughed and part turnips) has since Christmas last undergone a great and surprising alteration. The situation is on the side of a hill, inclining to the south, and the land has been continually moving in that direction, imperceptibly indeed at the time, but now the effect is very apparent. The upper or northern side, now planted with turnips, is sunk two or three feet, and is full of clefts or chasms, some of them a foot deep, and many of them filled with water. Two or three are as large as ponds, being six or eight feet deep, and ten or twelve square. Part of a hedge, which divided the fields, is moved about three roods to the southward, so as to form an angle with the two ends which it was upon a line with before. Another hedge is broken asunder, and there is now a gap of eight feet where before it was contiguous. Between the fields is a large coppice, which is also full of cracks and pits of water, and a large oak therein is apparently falling. The southern part, which has been ploughed this winter, and was then on a level with the rest of the field, now overhangs it like a precipice about the height of twelve feet, and is rendered quite useless for the purpose of sowing, as is all the rest for pasture or tillage. That land on each side which has not moved, is covered by the rest, which folds over it at the height of six or seven feet.

Numbers of people daily resort to see it, and where it will end nobody knows, as in two or three days time, especially after great rains or snows, fresh alterations are still perceived. The History of England makes mention of a similar case happening at Westerham in the reign of Queen Elizabeth.

As the best verbal description must be inadequate, if this imperfect one should induce some of your ingenious correspondents to visit the place, and take a sketch of it in its present form (and I assure him the strangeness of the sight

will highly reward his trouble) it might further contribute to the satisfaction of your readers, and thereby answer the design of your constant purchaser,

1756, March.

GRANTICOLA.

To Granticola.

SIR,

THOUGH a physical solution of the appearance at Toy's Hill, as described by you in last Magazine, might come more plausibly from one that had had an opportunity of inspecting it, and that something perhaps might be gathered from the nature of the stratum in the part described; yet I shall venture to offer you a hint concerning the cause of the ambulation of this portion of solid earth, not only not inadequate to the fact, but also confirmed, as I think, by experience. I suppose then there must be an even and smooth layer of some kind, probably of clay, underneath this floating field, to the North at the depth of three feet, and to the South at the depth of twelve, with a small vein of water upon its surface, just enough to moisten it. Now as the last summer was remarkably wet, and the winter rather so than otherwise, and the declivity of the hill would give a propensity to slide, a very small matter, it is apprehended, in such circumstances, might serve to put the mass in motion; and when I consider, that an earthquake was felt in the South of England, on the 1st of November last, I incline to believe, that the concussion of this island, though so slight, might be sufficient to set this ground in motion. This is my conception of the matter, and I think it greatly supported by an incident at Pillingmoss, in Lancashire, and the reason commonly assigned for that; 'In February 1745, on the East side of Corlew Hill, a part of Pillingmoss floated down Danson's, or Wild Boars Dales, and drove before it a vast quantity of mud, loose turfs, and black water, and covered with that kind of matter near 50 acres of ground (almost 20 of which was improved ground) to a great thickness; and sliding on, it reached as far as Dr. Danson's house, and pressed it down.' This account I have from a pamphlet, published on the occasion, where it is observed there had happened two such slips of the same moss before, one that the author had seen about the year 1708 or 1709, and another which he had heard of from old people. The fluxion of the moss was very slow, on account of the thickness of the matter, though the said matter was in a liquid

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