fugal is greatest. But in the line BR the only effect will be, to diminish the weight of the column. The particles will not move, unless they are fluid themselves, and connected with another column of fluid particles terminating at the surface in a different direction, as B`Z or B C; when the same effect will be produced as we proved to take place by a communication between the columns A B and B C,-that is, a rising of the waters at R and a depression of those at C and Z. On the other side of C B Z, again, for reasons which are very obvious, the centripetal force will overcome the centrifugal, and the water must, consequently, rise at A. These conclusions, while they serve to demonstrate the fallacy of Mr. Bennett's theory, will, we apprehend, enable us to clear up those obscure parts of sir Isaac Newton's, which have heretofore been a stumbling block to the universal prevalence of his system. What we allude to more particularly is the phenomenon of tides rising higher in narrow seas, than they do in wide ones. I. If there be two lakes of equal size on the equator 90 degrees apart, as at A and C, connected with each other and with no other water, either by the channels A B and B C, or by the straight channel A C, or by the curved one A O C,—it is evident that the tides in the one would be equal to the tides in the other; for, since the water cannot rise at A without being depressed at C, it is manifest, that, as the lakes are equal, the rise in the one would be precisely equal to the depression in the other, and vice versa. II. If, on the other hand, one of the lakes be double of the other in surface, the tides in the smaller lake will be twice as great as the tides in the larger; for since by the supposition no water can get into either from an extraneous source, when the larger lake rises 4 feet the smaller one must sink 8 feet, and when the larger lake sinks 4 feet it must do it by raising the smaller one 8 feet. The same phenomena will appear, if the smaller lake be situated towards one of the poles,-say 60 degrees north latitude, and the larger lake on the equator;-say 90 degrees west. When the moon is on the meridian of the smaller lake she will be in the horizon of the larger one, and 60 degrees from the horizon of the smaller one; and consequently there will be a slight depression in the larger lake, and twice as great an elevation in the smaller:-but when the moon comes to the zenith of the larger lake she will be in the horizon of the smaller; in which situation she produces as great an effect as she can produce; and there will be a considerable rise in the larger lake, with twice as great a depression in the smaller. III. If the smaller lake be at the north pole, and the larger one at the equator, there would still be tides in them; for though the moon might be considered as constantly in the horizon of the smaller lake; yet she would produce unequal pressures on the waters of the large lake,-depressing it when in the horizon, and elevating it when in the zenith and nadir, and consequently producing double elevations and depressions in the smaller lake. What would take place with respect to these lakes, does absolutely take place as it respects the wide seas and the narrow. They are connected together in such a way as to permit the waters to rise in one sea while they are depressed in every other that is 90 degrees distant; and if the one where the waters rise be smaller than those where the waters fall, there must be a greater rise in the small sea than there is a depression in the larger. There cannot be a rise in one place without a depression in some other place; and that place has already been shown to be 90 degrees from the greatest elevation. What we have now said concerning the moon, is equally applicable to the sun;-only that his power is not so great as the moon's. For if you suppose D to be the sun, his distance from B 24000 semidiameters of the earth, and his weight 169282 times that of the earth; if the attraction of the earth for a particle of matter at C be 1, then will the attraction of the sun be If this force, again, be 1 24000X24000 169282= 1 3402. resolved into the forces C M and C B, then, as C M is 24000 times as long as C B, the gravity of a particle at C will be increased only one 24000th part of the sun's attraction at C. We might dilate on the new doctrine we have broached to account for the tides rising higher in the narrow seas than in the wide ones; but if we have demonstrated that tides in the lakes, situated as above, would rise inversely as the superficial extent of those lakes, the application of the doctrine to the seas themselves is so easy, that we shall leave it to be made by our readers. Indeed, we are vain enough to believe, that the hints of demonstration which we have here thrown out might be advantageously amplified by applying them to the various phenomena attending the ebb and flow of tides; but, for the present, we must leave such an amplification to those who are able to publish larger books than we can; and content ourselves with hoping that at some future time we may have another occasion of drawing the attention of our readers to this very interesting, though rather obscure, portion of astronomy. ART. V.-Letters from Virginia. By a Northern Man. THE following Letters were written by a Gentleman from the north during an excursion through Virginia. A series of the same kind will probably be given to the public in the course of the ensuing summer. Letter I. DEAR FRANK,-Inasmuch as I only mean to give you a few occasional sketches of Ould Virginia,' as captain Smith calls it, I shall content myself with merely reminding you that its first effectual settlement commenced somewhat more than two centuries ago, and a few years anterior to that of Plymouth, in 'Massachusetts, the oldest settlement, I think, in that quarter. Farther back than this I will not go; for, to use the words of the first historian of Virginia, so called after 'the most famous, renowned, and worthie of all memorie, queen Elizabeth' For the stories of Arthur, Malgo, and Brandon, that say a thousand years agoe they were in the north of America; or the Fryer of Linn, that by his black art went to the north pole, in the yeare 1360; in that I know them not. Let this suffice.' The history from whence this extract is taken is highly curious, and contains a variety of minute particulars of the dangers and hardships encountered by the early adventurers. Among these the most sagacious, brave, and enterprising, by far, was the famous captain John Smith, who, on all occasions of emergency, acted as a sort of dictator among them. It was he that negotiated or fought with the Indians; explored the neighbouring waters, and visited the Indian tribes on the Chesapeake and its tributary streams. He visited the Weanocks, Anontahocks, Appamattocks, Manahocks, Massawomocks, Kusharawocks, Sasquasahannocks, Acquintanakocks, Quiyoughcohanocks;' and all the names that end in nocks; at the end of which pilgrimage he breaks forth into the following poetic stanzas: Thus have I walkt a wayless way, with uncouth pace, But yet I know this not affects the minde, Which eares doth heare, as that which eyes doe finde.' The first explorers of James river, called Powhatan, after the great emperor, were, it appears, subjected to a variety of inevitable hardships; sometimes were ill governed, and not unfrequently rather difficult to govern. A writer makes the following complaints against a certain president of the colony: 'Had we,' says he, been as free from all sinnes as gluttony and drunkennesse, we might have been canonized for saintes; but our president would never have been admitted, for ingrossing to his private oatmeale, sacke, oyle, aqua vita, beefe, egges, or what not, but the kettell: that indeed he allowed equally to be distributed, and that was halfe a pint of wheat, and as much barley, boiled |