Volume 4 — Notes.

THE PENDULUM DEMONSTRATION OF THE EARTH'S ROTATION.

If the propounders of this theory had from the first explained that they do not claim, for the plane of oscillation, an exemption from the general rotation of the earth, but only the difference of rotation due to the excess of velocity with which one extremity of the line of oscillation may be affected more than the other, it would have saved a world of fruitless conjecture and misunderstanding.

For myself I can say that it is only recently I have become satisfied that this is the real extent of the claim; and I confess that had I been aware of it sooner, I should have regarded the theory with greater respect than I have hitherto been disposed to do. Perhaps this avowal may render more acceptable the present note, in which I shall endeavour to make plain to others that which so long remained obscure to myself.

It is well known that the more we advance from the poles of the earth towards the equator, so much greater becomes the velocity with which the surface of the earth revolves—just as any spot near the circumference of a revolving wheel travels farther in a given time, and consequently swifter, than a spot near the centre of the same wheel: hence, London being nearer to the equator than Edinburgh, the former must rotate with greater velocity than the latter. Now if we imagine a pendulum suspended from such an altitude, and in such a position, that one extremity of its line of oscillation shall be supposed to reach to London and the other to Edinburgh; and if we imagine the ball of such pendulum to be drawn towards, and retained over London, it is clear that, so long as it remains in that situation, it will share the velocity of London, and rotate with it. But if it be set at liberty it will immediately begin to oscillate between London and Edinburgh, retaining, it is asserted, the velocity of the former place. Therefore during its first excursion towards Edinburgh, it will be impressed with a velocity greater than that of the several points of the earth over which it has to traverse; so that when it arrives at Edinburgh it will be in advance of the rotation of that place; and consequently its actual line of oscillation, instead of falling directly upon Edinburgh, will diverge, and fall somewhere to the east of it.

Now it is clear that if the pendulum ball be supposed to retain the same velocity of rotation, undiminished, which was originally impressed upon it at London, it must, in its return from Edinburgh, retrace the effects just described, and again return to coincidence with London, having all the time retained a velocity equal to that of London. If this were truly the case, the deviation in one direction would be restored in the opposite one, so that the only result would be a repetition of the same effects in every succeeding oscillation.

It is this absence of an element of increase in the deviation that constitutes the first objection to this theory as a sufficient explanation of the pendulum phenomenon. It is answered (as I suppose, for I have nowhere seen it so stated in direct terms) that the velocity of rotation, acquired and retained by the pendulum ball, is not that of London, but of a point midway between the two extremes—in fact, of that point of the earth's surface immediately beneath the centre of suspension.

There is no doubt that, if this can be established, the line of oscillation would diverge in both directions—the point of return, or of restored coincidence, which before was in one of the extremes, would then be in the central point; consequently it would be of no effect in correcting the deviation, which would then go on increasing with every oscillation.

Therefore, in order to obtain credence for the theory, satisfactory explanation must be given of this first difficulty by not only showing that the medium velocity is really that into which the extreme velocity first impressed upon the ball will ultimately be resolved; but it must also be explained when that effect will take place, whether all at once or gradually; because, it must be recollected, the oscillations of the experimental pendulum cannot practically commence from the central point, but always from one of the extremes, to which the ball must first be elevated.

But this is not enough: there must also be shown reasonable ground to induce the belief that the ball is really free from the attraction of each successive point of the earth's surface over which it passes; and that, although in motion, it is not as really and as effectually a partaker in the rotation of any given point, during its momentary passage over it, as though it were fixed and stationary at that point. Those who maintain that this is not the case are bound to state the duration of residence which any substance must make at any point upon the earth's surface, in order to oblige it to conform to the exact amount of velocity with which that point revolves.

Lastly, supposing theses difficulties capable of removal, there yet remains a third, which consists in the undeniable absence of difference of velocity when the direction of oscillation is east and west. It has been shown that the difference before claimed was due to the nearer approach to the equator of one of the extremities of the line of oscillation in consequence of its direction being north and south; but when its direction is east and west both extremities are equally distant from the equator, and therefore no difference of velocity can exist.

I have directed these observations to the fundamental truth and reality of the alleged phenomenon; it is quite clear that these must first be settled before the laws of its distribution on the surface of the globe can become of any interest.

A. E. B.

Leeds, August 5. 1851.

Minor Notes.

The Day of the Month.

—Many persons might help themselves, as some do, by remembering throughout the year on what day the 1st of January fell, and by permanently remembering the first day of each month, which agrees with the first day of the year. Thus, this present year began on Wednesday, and the 6th of August is therefore Wednesday, as are the 13th, 20th, 27th. By the following lines the key to the months may be kept in mind:—

M.

Foreign English.

—The specimens given in "NOTES AND QUERIES" have reminded me of one which seems worthy to accompany them; in fact, to have rather a peculiar claim.

I believe the facts of the case to have been these. When it was known that Louis XVIII. was to be restored to the throne of France, a report was circulated (whether on any good authority I do not know) that the then Duke of Clarence would take the command of the vessel which was to convey the returning monarch to Calais. At all events the people of Calais expected it; and inferring that the English royal duke would pass at least one night in their town, and of course go to the play, they deemed that it would be proper to perform the English national anthem at their theatre. It was obvious, however, that "God save the King" was so very appropriate to their own circumstances, that, notwithstanding its Anglicism, it left less of compliment and congratulation for the illustrious foreigner than they really intended to offer. So that happy people, who can do everything in no time, forthwith prepared an additional verse. This being quite new, and of course unknown, they printed on the playbill, from which I learned it. If you give his lines a place in your pages, I will not say that the French poet's labour was thrown away; but for the time it was so, as the English duke did not accompany the French king. I believe that the additional verse was as follows:—

I am sorry that I can only speak from memory of the contents of a document which I have not seen for so many years; but if I may have made any mistake, perhaps some reader may be able to correct me.

S. R. M.

Birds' Care for the Dead.

—It is not uncommon to find in poets of all ages some allusion to the pious care of particular birds for the bodies of the dead. Is there any truth in the idea? for certainly the old ballad of "The Children in the Wood" has made many a kind friend for the Robin Redbreast by the affecting lines:

Herrick also alludes to the same tradition in his verses "upon Mrs. Elizabeth Wheeler, under the name of Amarillis." (Works, vol i. pp. 62-3.: Edin. 1823)

In the earlier editions of Gray's Elegy, before the Epitaph, the following exquisite lines were inserted:

And about the same time Collin's "Dirge in Cymbeline" had adorned the "fair Fidele's grassy tomb" with the same honour:

RT.

Warmington, Aug. 9. 1851.

Snake's Antipathy to Fire.

—There is in Brazil a very common poisonous snake, the Surucucu (Trigonocephalus rhombeatus), respecting which the Matutos and Sertanejos, the inhabitants of the interior, relate the following facts. They say that such is the antipathy of this reptile to fire, that when fires are made in the clearing away of woods, they rush into it, scattering it with their tails till it is extinguished, even becoming half roasted in the attempt; and that when an individual is passing at night with a torch, they pass and repass him, lashing him with their tales till he drop it, and the snake is immediately found closely coiled round the extinguished torch. The greatest enemy of this snake is an immense Lacertian, five and six feet long, the Tiju-açu (the great lizard—its name in the Lingoa geral): it is said that when the snake succeeds in effecting a bite, the lizard rushes into the wood, eats some herb, and returns to the conflict, which almost invariable terminates in its favour.

JOHN MANLEY.

Pernambucco, June 30. 1851.

Aldgate, London. (A Note for London Antiquaries)

—After this gate was taken down in 1760, Sir Walter Blackett, of Wallington, Northumberland, obtained some of the ornamental stone (part of the City arms, heads and wings of dragons, apparently cut in Portland stone, and probably set up when the gate was rebuilt in 1606), and used them in decorating Rothley Castle, an eye-trap which he erected on the crags of that name, near Wallington.

W. C. TREVELYAN.

Wallington Aug. 11. 1851.

Erroneous Scripture Quotations.

—Some of your correspondents have done good service by drawing attention to these things. Has it ever occurred to you that the apple is a fruit never connected in Scripture with the fall of man;—that Eve was not Adam's helpmate, but merely a help meet for him;—and that Absalom's long hair, of which he was so proud, and which as consequently so often served "to point a moral and adorn a tale," had nothing to do with his death, his head itself, and not the hair upon it, having been caught in the boughs of the tree?

P. P.