which they make their hard mortar with their mouths. These subterraneous passages are carried horizontally to vast distances, like passages from old castles, from which they emerge on any building or merchandise which they intend to attack. As they cannot carry up perpendiculars, all the ascents and descents are made by spiral roads.

For communication inside, they construct elliptical bridges; and Mr. S. had one 10 inches long, half an inch wide, and a quarter of an inch thick. It was strengthened by a small arch at bottom, and the centre of it was hollowed out for the safety of the passengers.

A smaller species build their city in the shape of an upright CYLINDER, about 27 inches high, and cover it with a roof of the same black earth, like the top of a mushroom, or the roof of a cottage which hangs beyond the walls. When one is too small they build others close to it, and five or six generally stand together.

The termes arborum build their nests between the arms and stems of a tree, at the height of 70 or 80 feet, sometimes as large as a sugar hogshead. They are composed of small particles of wood, and the gums and hardened juices of trees, worked by these industrious and interesting little creatures into a paste, and then formed in cells and apartments, in such connection with the tree that nothing can sever them.

The labourers among the TERMES BELLICOSUS are about a quarter of an inch long, and 25 of them weigh but a grain. There are about 100 to every soldier: they run faster than any insect of their size, and are always bustling about their affairs The soldiers are labourers who have advanced a stage to the winged state. They are half an inch long, and their jaws are adapted for piercing and wounding, being just like two very sharp awls a little jagged; while the mouths of the labourers are calculated only for gnawing and holding. In the third order, they are six or seven tenths of an inch in length, and are furnished with four large, brownish, transparent wings. Their size is equal to that of 30 labourers, or two soldiers, and they have two conspicuous eyes, to aid their search for new dwellings. They issue in such prodigious numbers, that they become food for birds, other insects, reptiles, and even man, so that not a pair in many millions establishes a new community.

They become in this state, from being the most active, industrious, fierce, and implacable little animals in the world, the most helpless and cowardly; the prey of other ants, who

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are every where seen dragging them to their nests. few who survive the general massacre of their race are preserved by the labourers of other nests, and by them elected kings and queens of new states. They enclose them in a small chamber of clay, with entrances large enough only for themselves, and become voluntary subjects, taking it on themselves to provide and fight for them, till their own progeny are numerous enough to divide the task with them.

They make pipes of the material of which they build. They thus line most of the roads leading to and from their nests, and pass through woods and over rocks in this secure manner, while, if alarmed, they retreat into their subterraneous passages. The common ant is their most formidable enemy; and as they cannot see, and are soft, while the others are hard, the termes never appear above ground, or out of their covered ways, any accident to which they instantly repair with unwearied industry. If destroyed several times they give it up; but if it be an important road, they soon restore it again. Thus making their approaches under ground, they ascend through the timbers, perforate them completely, and afterwards every wooden part of houses, till they have ruined them. The termes arborum sometimes form their nests in roofs, but more commonly in the trunk of a tree, perforating every part, and destroying every thing within and near it.

They destroy all the softer substances first, and are particularly fond of pine boards, eating away the entire inside, and leaving the surface as thin as paper. A stake in a hedge is their sure prey; of which they leave only the bark, and if the bark fail, or the outside of a beam, they cover it with their mortar, so that no one suspects their attack till the things are handled, or till a support gives way. Fallen trees they perforate in like manner, and what appears to be a sound piece of timber often proves but a shell, which may be crushed between the fingers. They seem aware, that if their work were seen from without they should be disturbed, so that the mischief is never suspected till it is perpetrated. Of deserted houses, or villages, they leave not a vestige in a few weeks. ›

If any one, from cruel curiosity, make a breach in their hills, a soldier runs out, and walks about the breach, to examine the cause of attack. If he go in to give alarm, two or three come out, who run as fast as they can, and these are followed by a large body. Some of them beat with their forceps on the building, and make a noise like the ticking of a watch, but shriller. If they find the assailant, they fix their hooked jaws in him, and draw blood copiously, and nothing

will remove them. If the attack is given up, the breach will be restored in half an hour, by myriads of labourers, who come every one with a burden of mortar in his mouth. The soldiers retire, except a few, and one, in particular, places himself close to the breach, turning leisurely about, and, at intervals, striking his forceps on the building. A loud hiss then proceeds from the labourers within, and they hasten, and redouble their pace at every such signal. If the attack is renewed the labourers disappear, and the soldiers are instantly out, and if the enemy is quiet they retire again, and the labourers proceed. But no soldier works, nor any labourer remains when defence seems to be necessary.

If the attack is persevered in, the soldiers never desist, and seem to court death, and commonly succeed in driving away negroes without shoes and stockings. Again the labourers barricade every avenue to the interior, and they and the soldiers die voluntary deaths before the royal chamber. If the attack has not reached that chamber, they will block up every avenue, and speedily restore the whole building. If the royal chamber is outraged, the distress and confusion of the poor insects is extreme, and they continue their attentions and loyalty to the last.

One species is the marching termes. These move in regular columns, a soldier directing a body of labourers, and quickening their pace by blows on the ground with his forceps.

Of a Thermometer for measuring the highest Degrees of Heat. By JOSIAH WEDGWOOD.[1782.]

The

MR. W. adopted argillaceous earths for his measure. diminution of their bulk by fire is a distinguishing character of this order of earths. It begins at a low red heat, and proceeds regularly till the clay becomes vitrified, even to a fourth of their dimensions. Of all the sorts, the purest Cornish porcelain clays were the best adapted, both for supporting the intensity and measuring the degrees of fire; the pieces are then put into a brass gauge, wider at one end than the other; and as the piece diminishes in bulk, it slips down the gauge, which is graduated, and determines the contraction and the degree of heat.

The scale commences at a red heat visible in daylight; and the greatest heat which Mr. W. could contain in his furnaces was marked 160° by his clay thermometer. Swedish copper melts at 27°, silver at 28°, and gold at 32°. Brass

is in fusion at 21°. The welding heat of iron is 90°, and cast iron melts at 130°: it is fluid at 150°. Glass furnaces are 114° to 124°. Delft ware is fired at 40°, and Queen's ware at 86°: Worcester china vitrified at 94°.

On the proper Motion of the Sun and Solar System among the Stars. By WILLIAM HERSCHEL.

[1783.]

Does it not seem very natural, says Dr. Herschel, that as there are so many changes among the stars; many increasing their magnitude while others appear to vanish; several of them suspected to be new comers, others that are lost to our sight; the distances of many actually changing, while many more are suspected to have a considerable motion; does it not seem natural that, probably, every star is more or less in motion? Now, if the proper motion of the stars is admitted, who can say that our sun and the solar system is not partaking of the general agitation ?

Dr. H. examines the recorded motions of the stars; and in a list of 27 of the principal, he proves that 22 of these motions will be satisfied, if the sun has a proper motion towards the constellation Hercules; and he concludes that the sun and solar system are actually moving towards the star marked gamma in Hercules; and that the velocity of the sun is about equal to that of the earth in its orbit.

Account of some late fiery Meteors. By Dr. BLAGden.

THE first was seen August 18. 1783, as a luminous ball, leaving a train behind, and yielding a prodigious light. It rose in the N. N. W., passed to the east, verged southward, and gradually disappeared. It continued visible about half a minute, and seemed in its course to undergo a change compared to bursting.

It was seen in Shetland, at sea, in the Hebrides, and at Aberdeen and Edinburgh. It proceeded over Yorkshire; and in Lincolnshire deviated to the east, and appeared to burst. It then passed over Cambridgeshire, Suffolk, and Essex, and at Ostend and Calais was considered as vertical. It was also seen at Brussels and Paris, and altogether through a course of 1000 miles. Nothing was more surprising than the brilliant and intense light which it afforded.

A comparison of its elevation in different places proves that it was from 57 to 60 miles in height, where, by theory, the air is 40,000 times more rare than with us; and yet its re

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ports were heard at double the distance, like a volley of small arms, and apparently at the same time in Lincolnshire and Kent. Dr. B. calculates that it was half a mile across, and two miles long, while its train was 10 or 12 times longer than the body. Such an enormous mass, as large as a considerable mountain, moving with such extreme velocity, affords just matter of astonishment.

Its velocity was so great, that it appeared to pass through 1000 or 1200 miles in 40 or 45 seconds, which gives from 20 to 25 miles per second; that is, 100 times more rapid than sound or a cannon ball, and greater than the velocity of the earth in its orbit. Dr. B. concludes it to have been at 20 miles per second, and 90 times greater than sound.

Another meteor was seen on the 6th of October, 1783, smaller than the other. It passed from the northward; but was so rapid, that though Dr. Blagden saw it himself, he could not distinguish whether it passed to or from the S. E. Its height must have been 40 or 50 miles, and its velocity above 12 miles per second.

Dr. B. speculates on the cause and source of these bodies, but a velocity so near that of the earth in its orbit seems to prove that they are unconnected with our globe, and perhaps only become luminous and noisy by passing through our atmosphere.

On the Construction of the Heavens. By Dr. Herschel. FOR the purpose of viewing the fixed stars, Dr. H. constructed a telescope with a large aperture, so as to increase the light. Its field of view was a quarter of a degree in diameter.

On applying this telescope to the milky-way, it completely resolved the whole into small stars, which his former telescopes had not light enough to effect. He says, "The glorious multitude of stars that presented themselves about the hand and club of Orion was truly astonishing. I found that six fields, promiscuously taken, contained 110, 60, 70, 90, 70, and 74 stars each. A belt of 15 degrees broad, and two wide, or the quantity which I often view in an hour's time, could not contain less than 50,000 stars large enough to be numbered; and I suspect there were twice as many more which I could not see for want of light, though my 20-feet reflector had an aperture of 18 inches.'

"It is a very remarkable circumstance of the nebula and clusters of stars, that they are arranged into strata, which