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By Dr. Herschel Page 577 Observations on the camel's sto
On the reproduction of buds. By : Narrative of the eruption of a vol-
596 cano in the sea off the island of
ship's head. By Capt. Flinders ib. On the motions of the tendrils of
By Sir Eve-
sex; in a letter to Sir J. Banks. of investigating how far the power
By Mr.J. R. Trimmer Page 626 of our telescopes may be expected
On the structure of the starry hea- Theory of mists. By Sir H. Davy ib.
By Dr. Herschel ib. On the geology of Plymouth and its
brain and nerves,
to the sidereal part of the heavens, position and analysis of the in.
632 some remarks on their relative
636 Observations on the migration of
On the nature and cause of the On the corrosion of copper sheeting
pulse. By Dr. Parry 639 by sea water, and on methods of
the colours used in paintings by their application to ships of war
the ancients. By Sir H. Davy 640 and other ships. By Sir Hum-
On the safety lamp. "By Sir Hum- trical combinations to the preserv-
ation of the copper sheathing of
gravity. By Sir Ev. Home ib. On the magnetising power of the
648 On the nervous circle which con-
Account of the Burning Concave Glass, made at Lyons, by
M. VILLETTE. - [1665.] Its figure is round, being rather above thirty inches in diameter. On one side it has a circular frame of steel, that it may keep its just size. It is easy to remove it from place to place, though it weigh above a hundred weight, and is easily put in all sorts of positions. The focus is distant from the centre of the glass about three feet, and is about half an inch in diameter. One may pass one's hand through it, if it be done nimbly; but if it remain there for one second only, there is danger of receiving much hurt.
Green wood takes fire in it in an instant, as do also many other bodies. A small piece of pot-iron was melted, and ready to drop down, in
40 Sec. A piece of silver was pierced in
24 A thick nail was melted in
30 The end of a sword-blade was burnt in A brass counter was pierced in
6 A piece of red copper was melted, ready to drop down, in
42 A piece of quarry-stone was vitrified in
45 Watch spring steel melted in
9 A mineral stone was calcined and vitrified in
1 A piece of mortar was vitrified in
52 In short, there is hardly any body which is not destroyed by this heat. To melt by it any great quantity of metal much time would be required, the action of burning not being performed but within the size of the focus ; so that usually only small pieces are exposed to it.
M. de Villette afterwards made another of 34 inches diameter, which melted all sorts of metals, even iron itself, of
the thickness of a silver crown, in less than a minute of time, and vitrified brick in the same time, and as for wood, whether green or dry, it set it on fire in a moment.
M. Auzout's Speculations on the Changes likely to be discovered
in the Earth and Moon, by their Inhabitants. — [1665.]
I HAVE sometimes thought on the changes which it is likely the supposed inhabitants of the moon might discover in our earth, to see whether reciprocally I could observe any such in the moon. For example, that the earth would appear to the people of the moon to have a different face in the several seasons of the year ; and to have another appearance in winter, when there is scarcely any thing green on a very great part of the earth; when there are countries all covered with snow, others all covered with water, others all obscured with clouds, and that for many weeks together. Another face in spring, when the forests and fields are green. Another in summer, when all are yellow, &c. Methinks such changes are considerable enough, by the force of the reflections of light, to be observed, since so many
differences of lights are seen in the moon.
We have rivers considerable enough to be seen, and they enter far enough into the land, and have a breadth sufficient to be observed. There are fluxes in certain places, that reach into large countries, capable of making there some apparent change; and in some of our seas there float sometimes such bulky masses of ice, that are far larger than the objects which we are assured we can see in the moon. Again, we cut down whole forests, and drain marshes, of an extent large enough to cause a considerable alteration : and men have made such work, as have produced changes large enough to be perceived. In many places also are volcanoes sufficiently large to be distinguished, especially in the shadow : and when forests or great towns are on fire, it can hardly be doubted, but these luminous objects would appear, either in an eclipse of the earth, or when such parts of the earth are not illuminated by the sun. I have sometimes thought whether it might not be, that all the seas of the moon, if there must be seas, were not on the side of the other hemisphere, and that for this cause it might be that the moon turns not her axis, as our earth, in which the lands; and seas are, as it were, balanced. This also
be the cause why there appear not any clouds there, nor any vapours considerable enough to be seen, that are raised from
the earth; and that this absence of vapours may also be the reason that there is no twilight there, as it seems there is none, 1 myself at least not being able to discern any: for I think the reputed inhabitants of the moon might see our twilight, since it is much stronger than the light afforded us by the moon, even when full; for a little after sun-set, when we receive no more the first light of the sun, the sky is far clearer than it is in the fairest night of the full moon. And since we observe in the moon, when she is increasing or decreasing, the light she receives from the earth, we cannot doubt but that the people of the moon should likewise see in the earth the light with which the moon illuminates it, with perhaps the difference there is between their magnitude. Much more then should they see the crepuscular light, being, as was said, incomparably greater. But yet we see not any faint light beyond the section of the light, which is almost every where equally strong, and we there distinguish nothing at all, not so much as that clearest part called aristarchus, or porphyrites, as I have often tried ; although one may there see the light which the earth sends thither, which is sometimes so strong, that in the moon's decrease I have often distinctly seen all the parts of the moon that were not enlightened by the sun, together with the difference of the clear parts and the spots, so far as to be able to discern them all. The shadows also of all the cavities of the moon seem to be stronger than they would be if there were a second light. For although afar off the shadows of our bodies, en. vironed with light, seem to us almost dark; yet they do not appear so in the same degree as the shadows of the moon; and those on the edge of the section should not appear in the like manner.
Swarms of mischievous Insects, in New England.-[1666.]
Some few years since in New England, there was such a swarm of a certain kind of insects, that for the space of 200 miles they destroyed all the trees of the country. There appeared innumerable little holes in the ground, out of which they broke forth in the form of maggots, which turned into flies, with a kind of tail or sting, which they struck into the tree, and thereby envenomed and killed it.
The like plague is said to happen frequently in the country of the Cossaks or the Ukraine, where in dry summers they are infested with such swarms of locusts, driven thither by an east or south-east wind, that they darken the air in the