PROGRESS OF JOURNALISM. Sir, The article extracted in the last Number of the Mechanics' Magazine, from the Journal of the French Statistical Society, founded by M. Cesar Moreau, was publishod at Paris, in the following table (certainly universally interesting), in April, 1828, by M. Balbi, the geographer. Sept. 26, 1831. Yours, &c. Names of the Parts of the World, and the T. States thereof. Periodicals ON THE SUSPENSION-BRIDGE AT CLIFTON. THE FIRST STONE LAID JUNE 20, 1831. By the Rev. W. L. Bowles. O'er the red rocks, and woods, and stream below, Artist! thy fairy web of net-work throw, Bridging the fearful chasm. The sea-boat, "Trough,”‡ Like small canoes, as toiling up the stream Speak not these works of Nature and of art, *This is the most southern Journal of the globe. Alluding to a Welsh trader, called the "Severn Trough." 7 ciety of the present day, than the discovery and settlement of the doctrine of the universe by Newton; though one philosophically weighed against the other, be but as a mite in the scale. When a man argues on wrong principles, encourage him to talk; the more he says the more he hastens to the trap which is sure to catch him at last. Such will be my case, if my theory of locomotion be grounded on false principles; such has been the case with my opponent Mr. Cheverton, who has illustrated his locomotive ideas by the diagram of a machine, vol. xv., page 391, that cannot stir from the ground on which it stands. Mr. C. reasons correctly on statumotion, or so long as he is fixed to the ground, but take him off his legs, and he is lost. He becomes Antæus in the arms of Hercules. Long practice has familiarized me with locomotive investigations, and I did not think its simple principles had been so obscured by statumotive prejudices, as to be imperceptible to the class of men who have opposed my theory. I must own its being so misunderstood, does not speak much in favour of the clearness of my reasonings upon it. It may, nevertheless, be true, as I believe it mainly to be, and it is immaterial whether it is assaulted by geometrical or algebraical assailants, or whether it is illustrated by weights, springs, or steam. Truth has but one face, and whatever way she turns it, the same beauteous lineaments are discoverable. In my last communication, vol. xv., page 472, I spoke of " statumotion," a word which I beg leave to use in opposition to locomotion: and as, from the writings of my opponents, I am led to believe they have no distinct notions of the real difference of these motions, I trouble you with a few remarks in explanation of that difference. P, In the diagram, the weights 's P show statumotive power, or power whose point of support and reaction is fixed to one part of the plane, or other immoveable place, during the motion of the machine, GL show locomotive power, or power whose point of support and reaction moves to different parts of the plane during the motion of the machine. Let d represent the distance from A to B (supposed to be a full circumference of the wheel w) s, statumotive power, ap THE TIDES THE OTAHEITE PHENOMENON. plied to the axle or frame of the carriage, the circumference of the carriage-wheel to which locomotive or statumotive power is applied; p, or P, statumotive power applied to the rim or any lesser radius of the wheel w; l, or L, locomotive power applied to the rim or any lesser radius of the wheel w; c, or C, the circumference of the wheel, crank, or pulley, to which either locomotive or statumotive power is applied. Now, in running the carriage from A to B a full circumferencew) s will have descended the length dw, and will have descended a full circum. ference, or cwd. Like spaces in like times, may argue like power with the same resistance, and experiment sanctions it in this case. But C being supposed only half the circumference of e == L will descend only half the space in the same ds, agreeably to Mr. Cheverton's note to 3 L 3 × C+d=ds, as before. To This is the difference between statumotive and locomotive power, and whether or L be a weight, or steam-engine, or barrel-spring of like intensity as at G, is of no consequence to the motion, as they all must have their reaction on the frame of the machine, which reaction ultimately terminates in the points A and H; and similar reaction is, I presume, always the result of similar action as to its line of direction. I intend shortly to trouble you with a paper, to prove the truth of the 5th proposition of my theory, vol. xv,, page 150, on the principles of reaction. 6 9 THE TIDES THE OTAHEITE PHENOMENON EXPLained. 01⁄4 Sir,-Since my last communication, I have been fortunate enough to meet with a seaman who, about four years ago, was several months at the island of Otaheite. And, although only a mate of a small vessel, I found him to he a very intelligent Scotchman, When I read to him Kotzebue's and Mr. Bennett's statements relative to the tides at Otaheite, he coolly replied, That Mr. Bennett, not being a seaman, might have been misled by appearances. For that the coral reefs were certainly always under water at noon and midnight, Kotzebue, he added, had evidently never given the matter any serious consideration. In continuation, he stated, 'that the depth of water close to the shore is as great as it is for many miles out at sea; that the time of high water, at the change of the moon, is at 1 hour 25 min. P. M., at full moon, 1 hour 25 min. A. M.; that the vertical rise of the full and change tides are about 6 feet, or the total rise from low to high water 12 feet; and that, the corresponding rise and fall of the neap tides, is 2 feet 10 inches, or the total rise 5 feet 8 inches.' And, He positively assured me, that the coral reefs were not to be seen every morning and evening, and certainly not for more than ten or twelve days during the period of a lunar month. when seen to the greatest advantage, it was about 8 in the evening and morning, on the first day after full and change; and at these periods, the coral reefs did not appear to be elevated more than one foot above low-water marks.: The whole of the above statement, will appear to be in perfect unison with the Theory of the Tides. R Let A represent high-water mark on the day of change. B, that of low water. Then AB 12 feet, make BR 1 foot; then will RB be the portion of the reef seen above low water. Upon AB, describe a circle, draw RD perpendicular to AB, and draw DC to the centre. Then the times the water will rise from B to R, and from B to A, will be as the arches BD, BA (Mecanique Celeste, tom. ii. p. 22). The same is true in the ebbing of the tide. Now, the time the tide rises from B to A, on the day of new or full moon, is six hours ten minutes, nearly also CR 5 Cos. DB= = =8333333.. DB CD 6 33° 33': hence 180: 33° 33' :: 6 10 110; that is, the water rises from B to R in 1 hour 10 minutes. Again, the time of low water at Otaheite, on the day of change, will be at 7 35, P. M., consequently, 7 35 1 10 6 25, and 8 45. That is, on the day of new moon, the tops of the coral reefs will make their appearance above the level of the sea, at 25 minutes past 6, P. M., and continue visible till 45 minutes past 8; and on the following morning, they will be visible at 46 minutes past 6, and continue to be seen till 6 minutes past 9. Now, by having the different vertical rises of the tide when the moon is 1, 2, 3, &c. days old, we might compute the respective periods in the evening and morning the reefs make their appearance above water, and the time they continue visible. It may be remarked, that the reefs will certainly be seen a day or two before new moon; in that case, they will be seen a little earlier in the mornings and evenings. A similar appearance will also take place about full moon. But the reefs can never be visible at noon or midnight. For, make CS2 f. 10 in. = CP, then will P and S represent the positions of high and low water at the time of quadrature or neap tides. In that case R will be 2 feet 2 inches under low water mark. Now, as the time of low water is advancing from 7 to 35 minutes P. M., to midnight low water mark, is ad. vancing from B to S, and will pass the point R, before the ebb tide can take place at midnight. For a similar reason, the reefs will always be under water at Yours, &c. G. S. noon. nished by our able correspondent, G. S., will be found in Captain Beechey's late Voyage to the Pacific. "To make this deviation," says Captain B.," from the ordinary course of nature intelligible, it will be better to consider the harbour as a basin, over the margin of which, after the sea-breeze springs up, the waves beat with considerable violence, and throw a larger supply into it than the narrow channels can carry off in the same time; and, consequently, during that time, or until the basin is full, which occurs about noon, the tide rises. As the wind abates, the water subsides, and the nights being generally calm, the water finds its lowest level by the morning."—ED. M. M.] NEWTON'S SUPPLEMENTARY PROBLEMS. Sir, I have for the last two years been a constant reader of your valuable Magazine, and have derived much edifi cation from the able solutions given by most of your contributors, of the mathematical questions. I have long wished to enrol myself as a young recruit in your scientific corps; but sensible that if I introduced myself too soon I would cut an awkward figure among such a welldisciplined band, I stuck to my Euclid and the Woolwich course (and, thank my stars, I have able and willing masters to drill me), until I thought myself in some degree qualified for the situation of a volunteer in your corps. Without further preface, however, I shall proceed, Mr. Editor, to give you the result of some of my juvenile lucubrations, trusting, if I should fail in my first attempt, you will give me a second trial before you drum me out of the regiment, or turn me over to the awkward squad. On reading 's solutions of the three problems from the Appendix to Euclid's Elements, by Mr. Isaac Newton, (au unfortunate name for a tenth-rate mathematician), I was very much dissatisfied with his solutions of the two last questions, and my belief that I had reason to be so was confirmed by reading Kinclaven's last communication (No. 417.) The following solutions, I trust, will be found to be done in a more soldier-like manner. Problem. Given the vertical angle, the rectangle contained by the sides, and their sum or difference to describe the triangle. |