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Stray Thoughts on

living one-the French, for instance, which some of our light writers, if that is the proper term for our writers of light reading, seem to reckon it the bounden duty of every living wight to be acquainted with. In that case, what should we do but pamper the vanity of one nation by as unjust a sacrifice of the rights of all the others, as if we should condemn the latter to be the natural slaves of the former. We should, in fact, render them slaves in soul, if not in body. By this measure we should also deprive ourselves of a thousand works of genius, which could not be written in that language so as to produce the effect they would in others. Beneath the genius of Shakspeare or of Schiller, the French language sinks, and thousands of thoughts find utterance in English or German, which it is physically impossible to transfer to French, even by the aid of paraphrase. The same objection applies to all languages.

Again. It is a fact demonstrated by experience, that at the first formation of a language, or shortly after, a genius is awakened by the free liberty of wordcreation enjoyed, which the subsequent annals of a nation seldom or never can parallel. Our Elizabethan age is an evidence of this-as well as the German Elizabethan age, or, as we might term it, "Cradle age," apparently not yet exhausted. A continual freshness and activity is kept up in the literary world by the continual awakening of new languages, and the cousideration of their novel powers, which could not be experienced if one language, even the most perfect conceivable, were adopted. Take the Greek for instance, esteemed by many the finest of all,-in its cradle age, when all was new, we know that it produced masterpieces which are indeed, as one of their noblest historians phrases it, possessions for ever;" but when that first noble enthusiasm had settled down, though the language remained equally beautiful, nervy, and expressive, it produced no author at all calculated to compete with the great names of literature, save Theo

critus.

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The rise of a new language communicates, as it were, an impetus to all around it, which naturally endeavours to emulate any peculiar excellence it may possess. Our age of Anne was partly created by the developement of

the French classical literature, and who can doubt that the energy lately manifested in the age of the Regent, was greatly, was principally owing to the rise of German, which diffused as it were an universal freshness through the literary horizon.

Not with feelings of jealousy and regret, therefore, ought we to eye the developement of any new language and literature, but with those of pleasure and love (if so German a term can be allowed), as adding something to the patrimony of mankind and of ourselves. Another tongue is even now beginning to manifest signs of youthful energy to the east of Europe,

let us regard it as one of the happy fortunes of our times, that they will most probably witness the creation of the Russian literature, and the polishing of the Russian language.

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"fall

XXXV. The votaries of " Science" are generally loud in their condemnation of the pursuits of the votaries of Language," seemingly unconscious that their own vocation chiefly consists in the study of" Gibberish." A person who is learning that a curve" is by him to be entitled a rabolic curve," is, one would think, engaged in no very intellectual occupation, when compared with him who is tracing the meaning of the word "Parabola," instead of repeating it like a parrot. A. C. C.

Mr. URBAN,

THE

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pa

Summerlands, Exeter, Dec. 1. HERE are few subjects within the compass of human inquiry, that can be deemed of greater interest than that which tends principally to establish safety of intercourse between nations, in the mutual exchange of works of art, and natural productions. Such useful investigations, before they can assume the form of a regular essay, are made known through popular works like yours, and by communicating with eminent characters, whose sentiments are thus elicited. In my last paper, the rising science of Magnetic Variation was cleared of a multiplicity of poles in both hemispheres; rendering important calculations comparatively simple and unembarrassed. It will be the present object, as far as can be warranted by facts and observations, to trace the polar orbit, within, and on the surface of the earth, occasioning the constant increase and decrease of

Figure 1. is a section through the meridian of the north west magnetic pole, P being the point of maximum magnetic intensity, where the needle would stand perpendicular, in prolongation of the radius C 5 P, on which 5, the real magnetic pole, will appear to be situated. The dip of the needle at 1, is by observation, the angle 3, 1, 2, of 70°. Were the place of the south east pole precisely known, it could be calculated, according to its action, inversely as the square of the distance, how much it repelled 1, the north end, and attracted 3, the upper and south extremity of the dipping needle. As, however, extreme accuracy cannot be obtained without indispensable observations at the very posi-tion of the poles, let it be supposed that the needle points to the magnetic

pole 5, in the line 3, 1, 5, of its inclination to the horizontal, or tangent 2, 1, 7, at the extremity of the semidiameter, C 1. It is evident, that the compliment 3, 1, 4, to the dip, is equal to the interior angle 5, 1, C. We have the angle at the centre, PCI, equal to the difference of latitude between P and 1. The radius, 1C of the earth, is also given. It then remains to find trigonometrically, the side 5C, intercepted between 5, the real place of the magnetic pole, and C, the centre of the earth, by the following obvious calculation, for whose facility and brevity we are indebted to John Napier, Baron of Marchiston, though his fine invention was, as generally happens, much improved by scientific men.

PART II.]

posite latitudes and longitudes. It is evident, that the half of the west division will give the farthest south, and that of the east, the farthest north part of the magnetic equator, constantly changing on account of the movement of the poles in contrary directions. This will give on the section, the present south point of the magnetic equator, nearly at d of Fig. 1. The pole n, properly speaking, is on the west side of the section, Fig. 1, but is assumed there, to demonstrate the action of the south east pole, on the south end of the needle. Suppose the north west pole 5, not to exist, the dip of the needle at d would be the angle hdb; and supposing there were no south east pole n, the dip at d would be the angle adr. As these two poles, at an equal distance from d, neutralise the effect of each other, the needle will be horizontal on the tangent adb. In moving from the point d of the magnetic equator, to the northward, or southward, the needle is found to incline downwards, or dip to the nearest magnetic pole; while the other, or more distant, will attract the higher, and repel the lower end, inversely, as the square of the distance. At the point P, where the needle will stand perpendicularly over the pole 5, the effect of the pole n will be inconsiderable, as it will be very nearly in the line of the needle in that position. If we could at all times find the precise place of each magnetic pole, a requisite correction could be calculated, and applied to the apparent dip of the needle. An error of one degree, either in the place of the pole, or in the complement of the dip, will be found by trial, to make a difference of sixty miles in the depth of the pole, and of 42 in the length of the transverse diameter, 5, 6, of the real polar orbit.

It remains to have made known what may be the number of degrees of latitude which the pole may be distant from N, the earth's north pole, when in the situations 2 and 4 of its orbit, supposed, for illustration's sake, to be on the parallel of 80° of fig. 3. The moving pole will arrive under the meridian of 10° west longitude, in 180 years, reckoned from 1817, or in the year 1997. It will then be found by the dipping needle, to be at 4, after describing one fourth part of its orbit, or some unknown curve, such as P4 of fig. 3. The points 4 and 2 becoming

597

thus made out, after a long period, the conjugate diameter 2, 4, of the orbit will be obtained. The lives and property of a great proportion of maritime nations depend in a great measure, on the solution of a problem of vast moment; and a serious responsibility attaches where delay will prevent the accomplishment of a national object. The pole is now moving in a northeast direction, as proved, by comparing the accurate observations of intrepid navigators. Ere long it will pass on, under uncomeatable regions, for a long period of years. The process, while it can be followed, is obvious, safe, and facile. A run of a few degrees from the north coast of America, in such vessels as Sir John Franklin had, would lead to P, the former place of the pole, and where it would now no longer be found; but, probably, at some point, such as a of fig. 3. The latitude and longitude of a, where the needle would stand perpendicular, would be carefully taken. In five years more, the position a would be visited, when the dip would indicate that the magnetic power had moved on to n. After another period, it might be found at v, beyond which any farther pursuit might be impracticable; and would be unnecessary, as the nature of the polar orbit, and rate of movement, would thus be distinctly made out. The readiest mode of finding these points in the polar curve, would be to move on the line of no variation at the time, till the needle stood perpendicular on the point sought after. The orbit of the southeast pole would be discovered by a similar procedure; and if ice prevented it at any point of the line of no variation, oscillations of the needle, compared with similar ones in a similar latitude and longitude on the line of no variation in the northern hemisphere, would by analogy, furnish the place of the south-east magnetic pole.

The east variation, equally as the west, is occasioned by the position of the north-west pole P, in reference to the earth's pole N; and not by any imaginary pole in the north-east quar

ter.

For instance, the people at D, have an east variation NDP; and they will have no variation, when the pole comes under their meridian, which is the same as that of London. The inhabitants at B, have an east variation, NBP, and will have no variation,

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when the pole will twice come under their meridian, at 4, the first quarter, and at 2, the end of the third quarter of the whole orbit, P4m2 of figure 3. The inhabitants at e, had no variation with the pole at P, but will have an increasing west variation, as the pole moves in its curve over the points a, n, and v. Thus it appears that the single pole P, accounts for every description of variation; and in the southern hemisphere, although the south end of the needle is that principally acted on, still the variation is reckoned from the north end of the needle, but the dip there, is necessarily reckoned at the south extremity, in contradistinction to the north dip.

It is to be noticed, that every magnetised needle is naturally a dipping needle; and that it is rendered a horizontal needle by being balanced and attached to a card. Each end of the needle will point to its relative pole only when the needle lies in the plane of the two magnetic poles. In every other situation each pole will prevent the needle from pointing exactly to either; and the attraction and repulsion of the more distant pole will be always, according to what has been stated, showing strongly the necessity of the indispensable process recommended.

The dip of the needle has been diminishing from the period of the discovery of this phenomenon by Norman. As due attention was not paid in former times to the coincidence of the centre of gravity and centre of motion, recorded observations, though inaccurate, are still sufficient to show the fact of a diminution of dip, which I shall attempt to explain by a rationale, founded on statements sanctioned by a theory resulting from experiments and calculation. It is requisite to refer to plain and linear plates, because"Segniùs irritant animos demissa per au

rem,

Quam quæ sunt oculis subjecta, fidelibus."

Granting that Cavallo, in 1775, observed the dip with tolerable accuracy, we find at London its amount to be 72° 3', to be compared with the present dip of 70°. This for 54 years gives an annual decrease of 2' 16."6. The question necessarily arising is, when did the decrease commence, and when will the increase begin? Let fig. 2 be a section through the parallel of latitude AB of fig. 1, and 34" 30'

[XCIX.

from the equator; and having in its plane the transverse diameter, 5, 6, of the interior polar orbit, 2, 5, 4, 6, of fig. 2. The section is to be supposed parallel to the equator, and standing at right angles to NS, the axis of one hundred west longitude. Suppose radii passing from C, the earth's centre, through the cardinal points, 5, 4, 6, and 2, they would terminate on the surface at P, 4, m, and 2, of fig. 3; giving the four principal points of the exterior polar orbit, on every part of which the needle will stand nearly perpendicular, when the magnetic pole in its real interior orbit is on the radius or semidiameter of such point. There being no data for ascertaining the length of the conjugate diameter 4, 2, the number of miles which the magnetic power moves annually in its real and sensible, or apparent orbit, cannot be obtained till the important experimental process described shall have been followed. The number of miles cannot probably exceed eight in the exterior orbit, and which will measure half a degree on the equator, because the pole moves through the whole amount of the equatorial degrees, in 720 years.

To a person at G, at the upper part of section, fig. 2, the dip will be greatest when the pole is at 2 of its orbit; and will diminish while it is moving during 360 years through the west half of its orbit, 2, 5, 4; and will increase while moving through the eastern semiorbit, 4, 6, 2. To those situated at R, the effect will be the reverse; and to both it will be similar, when the pole is at 4 and 2. To those situated at E and W, the dip will increase when the pole is moving inwards from 2 to 5, and from 4 to 6, in the opposite quarter-orbit. The dip will diminish while the pole is moving outwards towards the circumference, from 5 to 4, and from 6 to 2 of the opposite quarter of the orbit. When at the points 2, and 4, the dip will be similar; and when at 5 and 6, it will be apparently the same. The case is different when the observer is not, as here, situated in the plane of the polar orbit. At present, the magnetic pole or power is moving eastward in its interior orbit, from 5, the utmost point of westing in fig. 2, towards 4; and the quarter of its interior curve equal to 5, 4, will correspond with the fourth part of the exterior orbit found by the dipping