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found in sundry parts of Siberia to a considerable quantity, and the tusks and teeth in particular, when less corrupted, are used all over Russia for ivory. Henricus Wilhelmus Ludolfus, in the Appendix to his Russian Grammar, mentions them among the minerals of Russia, by the name of Mam motovoikost, and says, that the Russians believe them to be the teeth and bones of an animal living under ground, larger than any one of those above ground.

Among the hills to the north-east of Makofskoi, the mammoths tongues and legs are found; as they are also particularly on the shores of the rivers Jenisei, Trugan, Mangasea, Lena, and near Jakutskoi, to as far as the frozen sea. The old Siberian Russians affirm, that the mammoth is

very like the elephant, with this only difference, that the teeth of the former are firmer, and not so straight as those of the latter. They also are of opinion, that there were elephants in this country when this climate was warmer : but that after the deluge, the air, which was before warm, was changed to cold, and that these bones have lain frozen in the earth ever since, and so are preserved from putrefaction, till they thaw and come to light. These animals must be of necessity very large, though a great many lesser teeth are found. But no person ever saw one of these beasts alive, or can give any account of its shape.

Lawrence Lang, in the Journal of his Travels to China, takes notice of these bones, as being found about the river Jenisei, and towards Mangasea, along the banks, and in the hollows occasioned by the fall of the earth. He calls them maman-bones, and informs us that some of the inhabitants are of opinion, that they are the bones of the Behemoth, mentioned in the 40th chapter of Job. The same author affirms, from the report, as he says, of credible people, that there have been sometimes found horns, jaw-bones, and ribs, with fresh flesh and blood sticking to them. The same is confirmed by John Bernard Muller, in his account of the Ostiacks; who adds, that the horns in particular have been found sometimes all bloody at the broken end, which is generally hollow, and filled with a matter like concreted blood; that they find, together with these teeth, or horns, as he calls them, the skull and jaw-bones, with the grinders still fixed in them, all of a monstrous size ; and that he himself, with some of his friends, has seen a grinder weighing more than 24 lb.

The accounts hitherto given of these maman-bones and teeth, or at least their most essential parts, are confirmed by a letter of Basilius Tatischow, director-general of the mines in Siberia, where he mentions the following pieces he had in his

own possession : a large horn, as he calls it, or tooth, weighing 183 pounds, which he had the honour to present to his Czarish majesty, and is now kept in the Czar's collection of curiosities at Petersburgh ; another large horn, which he presented to the Imperial Academy at Petersburgh ; another still larger than either of these two, which he caused to be cut, and carved himself several things from it, the ivory being very good; part of the skull, corrupted by having lain in the ground, and so large, that it seemed to him to be of the same size with the skull of a great elephant; the forehead, in particular, was very thick, and had an excrescence on each side, where the horns are usually fixed.

In Sir Hans Sloane's collection is one of the grinders of an elephant, which was likewise found in Northamptonshire. The above tooth was lodged at almost 12 feet depth in earth. Above it were the following strata: 1. The top earth, a blackish, clayey soil, about 16 inches. 2. Sandy clay intermixed with pebbles, five feet. 3. A blackish sand, with small white stones in it, one foot. 4. A loamy, softer sort of gravel, one foot. 5. A sharper gravel, about two feet. The tooth was found a foot and a half deep in this stratum of gravel. Below this fifth stratum there was a blue clay.

In his collection of quadrupeds and their parts is part of an elephant's skull, which was found at Gloucester after the year 1630, with some large teeth, some five, others seven inches in compass.

Observations towards composing a Natural History of Mines

and Metals. By Dr. NichoLLS. — [1728.] Of all the substances concurring to form the terrestrial globe, IRON probably bears the greatest share ; as it not only abounds in most kinds of stone, showing itself in varieties of crocus, all which gain a more intense colour by fire ; but also enters greatly into the composition of common clay; as may be judged from the similitude of colour between clay and dry iron ore; from the easy vitrification of clay ; from the resemblance between clay so vitrified and the clinkers of iron; from its deep red colour after calcination ; and, lastly, from its yieding pure iron, by being burned with oil.

When most pure, the ore is found under three different appearances. 1. A rich dry ore, whose scrapings exactly resemble an alkohol martis : this kind of iron ore has very nearly the colour of common clay. 2. A rich iron ore, with part of the wall of the load formed by a concretion of yellow crystals. In this stone the iron radiates from points forming segments of spheres, and where these spheres leave any interstices is found a crocus, or ochre. 3. A stone of iron of the kind used for burnishing plate ; it is of the species of the hæmatites. Both these last stones scrape into a deep crocus. And from the second instance we may conjecture, that the yellow colour in crystals arises from a crocus entangled with the stony salts.

The metallic substance found in Cornwall, and from which these islands are supposed to take their name, is Tin. It is never found but as an ore ; whereas gold is never found but as a metal, at least its ore is unknown, and all other metals are found sometimes as a metal, and sometimes as an ore. Tin always shoots into crystals, which are of different magnitudes, from two ounces in a single crystal, to such as escape our sight. These crystals are for the most part in. terspered in loads of other substances. As, 1. Tin crystals interspersed in a load of a kind of clay, in which is observable a considerable quantity of red ochre. 2. A kind of hard iron stone, in which are very small crystals of tin. 3. Some: what larger crystals, interspersed in a dry red ochre. 4. Tin crystals, interspersed with spar stone and a sort of marl. 5. Larger crystals, interspersed in a kind of clay and red ochre. When 100 sacks of the load, each containing more than a Winchester bushel, yield one gallon of clean ore, the load is esteemed very well worth working. Sometimes these crystals are so collected into one mass as to form loads of pure tin ore, and so large as to yield to the value of 1001.

every 24 hours.

The crystals seem to be the heaviest bodies the earth produces, except quicksilver and real metals. Their specific gravity is to water, as 90to 10; to rock crystal in water, as 904 to 26 ; to diamond, as 904 to 34; and to pure malleable tin, as found by repeated trials, as 903 to 78 ; from whence appears the possibility of what some miners affirm, viz. that a cubic inch of some tin ores will yield more than a cubic inch of metal.

A new Apparent Motion discovered in the Fixed Stars; its

Cause assigned; the Velocity and Equable Motion of Light deduced. By the Rev. James BRADLEY. — [1728.]

MR. Molyneux's apparatus was completed, and fitted for observing, about the end of November, 1725, and on December 3. following, the bright star in the head of Draco,

marked y by Bayer, was for the first time observed, as it passed near the zenith, and its situation carefully taken with the instrument. The like observations were made on the 5th, 11th, and 12th days of the same month, and there appearing no material difference in the place of the star, a further repetition of them at this season seemed needless, it being a part of the year when no sensible alteration of parallax in this star could soon be expected. It was chiefly therefore curiosity that tempted Mr. Bradley, being then at Kew, where the instrument was fixed, to prepare for observing the star on Dec. 17., when having adjusted the instrument as usual, he perceived that it passed a little more southerly this day than when it was observed before. This sensible alteration the more surprised them, as it was the contrary way from what it would have been, had it proceeded from an annual parallax of the star; about the beginning of March, 1726, the star was found to be 20% more southerly than at the time of the first observation. It now, indeed, seemed to have arrived at its utmost limit southward, because in several trials made about this time, no sensible difference was observed in its situation. By the middle of April it appeared to be returning back again towards the north; and about the beginning of June it passed at the same distance from the zenith as it had done in December, when it was first observed.

A nutation of the earth's axis was one of the first things that offered itself on this occasion; but it was soon found to be insufficient ; for though it might have accounted for the change of declination in y Draconis, yet it would not at the same time agree with the phenomena in other stars : particularly in a small one almost opposite in right ascension to y Draconis, at about the same distance from the north pole of the equator ; for, though this star seemed to move the same way, as a nutation of the earth's axis would have made it, yet changing its declination but about half as much as Υ Draconis in the same time, as appeared on comparing the observations of both made on the same days, at different seasons of the year, this plainly proved that the apparent motion of the stars was not occasioned by a real nutation, since if that had been the cause, the alteration in both stars would have been nearly equal.

When the year was completed, he began to examine and compare his observations; and having pretty well satisfied himself as to the general laws of the phenomena, he then endeavoured to find out the cause of them. He was already

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convinced, that the apparent motion of the stars was not owing to a nutation of the earth’s axis. The next thing that offered itself was an alteration in the direction of the plumbline, with which the instrument was constantly rectified; but this, upon trial, proved insufficient. He then considered what refraction might do; but here also nothing satisfactory occurred. At last he conjectured, that all the phenomena hitherto mentioned, proceeded from the progressive motion of light and the earth's annual motion in its orbit. For he perceived that, if light was propagated in time, the apparent place of a fixed object would not be the same when the eye is at rest, as when it is moving in any other direction, than that of the line passing through the eye and object; and that, when the eye is moving in different directions, the apparent place of the object would be different.

Mr. B. considered this matter in the following manner. He imagined CA to be a ray of light, falling perpendicularly on the line BD: then if the eye be at rest at A, the object must appear in the direction AC, whether light be propagated in time or in an instant. But if the eye be moving from B towards A, and light be propagated in time, with a velocity that is to the velocity of the eye as CA to BA; then light moving from C to A, while the eye moves from B to Ă, that particle of it, by which the object will be discerned, when the eye in its motion comes to A, is at C when the eye is at B. Joining the points BC, he supposed the line CB to be a tube, inclined to the line BD, in the angle DBC, of such a diameter, as to admit of but one particle of light; then it was easy to conceive, that the particle of light at C, by D A B which the object must be seen when the eye, as it moves along, arrives at A, would pass through the tube BC, if it is inclined to B D in the angle DBC, and accompanies the eye in its motion from B to A; and that it could not come to the eye, placed behind such a tube, if it had

any

other inclination to the line BD. If instead of supposing CB so small a tube, we imagine it to be the axis of a larger; then for the same reason, the particle of light at C could not pass through that axis, unless it is inclined to BD, in the angle CBD. In like manner, if the eye inoved the contrary way, from D towards A, with the same velocity, then the tube must be inclined in the angle BDC. Although, there

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