is a major-general too, and always dresses in his uniform, which ftill increases the refemblance. Every time I fee him, he fays or does fomething that recalls ftrongly to my mind the idea of our noble general. He laughs at the follies of his country, and holds thefe wretched prejudices in that contempt they deferve. "What would the "old hardy Romans think (faid he, talking on "this fubject) were they permitted to take a view "of the occupations of their progeny? I should "like to see a Brutus or a Caffius amongst us "for a little; how the clumfy vulgar fellows "would be hooted. I dare fay they would foon "be glad to return to the shades again."

Adieu; for fome nights paft we have been observing the course of a comet; and as we were the first people here that took notice of it, I affure you, we are looked upon as very profound aftronomers. I fhall fay more of it next letter. We have now got out of our abominable inn, andhave taken a final leave of our. French landlady. The Count Bushemi, a very amiable young man, has been kind enough to provide us a lodging on the fea-fhore; one of the coolest and most agreeable in Palermo.

Ever yours, &c.

LETTER XXVI

Palermo, July 2d.

OUR comet is now gone; we first

obferved it on the 24th. It had no tail, but was furrounded with a faintifh ill defined light, that made it look like a bright star shining through a thin cloud. This in all probability, is owing to an atmosphere, around the body of the comet, that causes a refraction of the rays, and prevents them from reaching us with that diftin&tnefs we obferve in bodies that have no atmosphere. We were fill the more perfuaded of this two nights ago, when we had the good fortune to catch the comet juft paffing clofe by a fmall fixed ftar, whofe light was not only confiderably dimm'd, but we thought we obferved a fenfible change of place in the star, as foon as its rays fell into the atmosphere of the comet; owing no doubt to the refraction in paffing through that atmosphere. We attempted to trace the line of the comet's course, but as we could find no globe, it was not poffible to do it with any degree of precifion. Its direction was almost due north, and its velocity altogether amazing. We did not obferve it fo minutely the two or three first nights of its appearance, but on the 30th it was at our zenith

here, (latitude 38° 10′; longitude from Lond. 13°) about five minutes after midnight, and last night, the first of July, it passed four degrees to the caft of the polar ftar, nearly at 40 minutes after eight. So that, in less than 24 hours, it has described a great arch in the heavens, upwards of 50 degrees; which gives an idea of the most amazing velocity. Suppofing it at the distance of the fun, at this rate of travelling, it would go round the earth's orbit in lefs than a week. Which makes, I think, confiderably more than fixty millions of miles in a day; a motion that vaftly furpaffes all human comprehenfion. And as this motion continues to be greatly accelerated, what must it be, when the comet approaches ftill nearly to the body of the fun! Laft night a change of place was obfervable in the space of a few minutes, particularly when it passed near any of the fixed stars. We attempted to find if it had any obfervable parallax, but the vast rapidity of its motion always prevented us; for whatever fixed stars it was near in the horizon, it had got fo far to the north of them, long before it reached the meridian, that the parallax, if there was any, entirely escaped us.

I shall long much to see the obfervations that have been made with you, and in other diftant countries, on this comet; as from these, we shall probably be enabled to form fome judgment of its diftance from the earth; which, although we could obferve no parallax, I am apt to believe

was not very great, as its motion was so very perceptible. We could procure no inftruments to measure its apparent diftance from any of the fixed ftars, fo that the only two obfervations any thing can be made of, are, the time of its paffing the polar ftar laft night, its diftance from it, and the time of its arrival at our zenith on the 30th; this we found by applying the eye to a straight rod, hung perpendicularly from a small thread. The comet was not in the exact point of the zenith, but to the best of our obfervation, about fix or seven minutes to the north of it. Laft night it was vifible almost immediately after funfet; long before any of the fixed stars appeared.` It is now immersed in the rays of the fun, and has certainly got very near his body. If it returns again to the regions of space, it will probably be visible in a few days, but I own I should much doubt of any such return, if it is really by the attractive force of the fun, that it is at prefent carried with fuch amazing celerity towards him. This is the third comet of this kind, whose return I have had an opportunity of watching; but never was fortunate enough to find any of them after they had paffed the fun; though those that do really return, appear at that time much more luminous than before they approached him.

The aftronomy of comets, from what I can remember of it, appears to be clogged with very

great difficulties, and even some seeming abfurdities. It is difficult to conceive, that thefe immenfe bodies, after being drawn to the fun with the velocity of a million of miles in an hour; when they have at last come almoft to touch him, fhould then fly off from his body, with the fame velocity they approach it; and that too, by the power of this very motion that his attraction has occafioned. The demonftration of this I remember is very curious and ingenious; but I wish it may be entirely free from sophistry. No doubt, in bodies moving in curves round a fixed centre, as the centripetal motion increases, the centrifugal one increafes likewife; but how this motion, which is only generated by the former, fhould at last get the better of the power that produces it; and that too, at the very time this power has acquired its utmost force and energy; feems fomewhat difficult to conceive. It is the only instance I know, wherein the effect increasing regularity with the cause; at last, whilst the cause is still acting with full vigour; the effect entirely gets the better of the caufe, and leaves it in the lurch. For, the body attracted, is at laft carried away with infinite velocity from the attracting body. By what power is it carried away Why, fay our philofophers, by the very power of this attraction, which has now produced a new power fuperior to itself, to wit, the centrifugal force. However, perhaps, all this may be reconcilable to reafon; far be it from