as r, the variation would be east or west, according as the moving pole happened to be east or west from the position r, where there would be no variation, when the pole would be directly under such site. If the line Po be supposed to be continued eastward and westward, to where the south-east pole begins to set sensibly, the variation on such continued line would be always the same, which is a case not known to exist. It must, from these statements, be concluded, that the magnetic poles move in some eccentric curve, such as Pr≈ P.

Churchman, who made the period of a revolution of the pole 1096 years, instead of what it appears to be, viz. 720, situated his north-west pole in 1340 west longitude, and 580 north latitude, or nearly at c of the figure. This situation on the west coast of North America, has been frequently visited by navigators, without any indications of such pole by the dippingneedle; and were it real, the horizontal needle would have pointed south, when passing through the Sound close to the south of its imagined site. The eminent mathematician, Euler, placed his north-west pole at e of the figure, in 76° north latitude, and 96° west from Teneriffe, or nearly in 113° west longitude. This position, about seven and a half degrees from the real magnetic pole, and north-west from it, was ingeniously imagined, and enabled that great man to account tolerably for the variation in Europe and America. Captain Parry's first voyage completely disposes of this pole, as Winter-Harbour in 74° 47' 13", and 110° 49′ longitude, was within 1° 12′ 47" of the latitude of Euler's pole, and but a little on the east side of its meridian. Now it is evident, that thus situated, the north end of the needle must have pointed to such pole; whereas there was a variation of 127° 47′ 50′′ east, shewing that the north extremity of the needle was attracted by the real north-west magnetic pole. Professor Hansteen situates his pole in 1769, 19° 43' from the north pole of the earth, and in longitude 259° 58' east. He makes it to move east ten or twelve minutes annually. Its place is nearly at a in the figure. From 1769 to 1819, fifty years, at the rate of twelve minutes of annual movement, would situate this pole in 90° west longitude, and 79° 13′ of latitude, at the period

when Captain Parry crossed its meridian. Had such pole existed, the needle would have pointed to it on this meridian, supposing it to be the real magnetic pole. The needle did not point due south, till the discovery-ships arrived on the meridian of 100° west longitude; and had the Professor's pole existed, the needle, influenced by both poles, would have given a variation of probably 145° east, instead of 180° on the real meridian, or line of no variation. Monsieur Biot, a philosopher of considerable eminence, has located a magnetic pole in 70° north latitude and 72° west longitude; and the great Dr. Halley, second only to Newton, placed a pole nearly in the same situation in Baffin's Bay. It is only necessary to say, that the alleged sites of these supposed poles have been explored, without finding any trace of their reality. At the south east cape of Greenland, in latitude 70° and longitude 23" west, and nearly at K of the figure, Professor Krufft situates his north-west pole. In frequently crossing the meridian of this imaginary pole, and so near that the horizontal and dipping needle must have been acted on, no such effect appeared. If a line be drawn from London to the place of four of these poles, it will pass much to the north and east side of the place of the real_north-west_pole P; and a line from London to Biot and Hansteen's pole, will pass a little to the southward of it. On magnetic principles, therefore, the needle at London ought to point to the eastward of the real pole. But how stands the fact? It is, that by means of the colatitude of London, the co-latitude of the pole, and the difference of longitude, the calculated is 1° 13′ less than the observed variation; or, in other words, the needle points to 1° 13′ to the southward of the real magnetic meridian; because the south-east magnetic pole, acting on the south end of the needle inversely as the square of the distance, attracts it eastward, and increases the calculated to the observed variation.

The distinguished authors mentioned did not, in point of fact (with the exception of Halley and Hansteen) suppose the existence of more poles than one in each hemisphere; and they placed their pole or poles so as to correspond with their respective theories. On the east side of the meridian of

London Dr. Halley situated his second pole, in 76° 30′ north latitude, and 30° east longitude. Captain Parry passed within a few meridional degrees of this position; and if such pole had been there, the north end of the needle must have been attracted by it into a considerable east variation; instead of which, it continued west. Other navigators passed near to the imagined site of this north-east pole, without perceiving any symptoms of its actuality. Halley's imaginary pole is placed in the figure at H. We have one other pole to dispose of, which is the learned Professor Hansteen's, said to be in a situation where it is utterly impossible to approach it, viz. in 85° 49′ north latitude, and 101° 30' east longitude; being only 4° 11' from the north pole of the earth, and nearly at h in the figure. In Captain Parry's last publication, a small decrease of the west variation, experienced in proceeding to Spitzbergen, is ascribed to the influence of this supposed magnetic pole in the north-east quarter. Supposing a ship to move eastward on any parallel of latitude, as that of 80° for instance, and to arrive at 1 of the figure; here the west variation would be the angle NIP, formed by the magnetic meridian 1 P with the meridian IN, of the place of observation. Let the ship move on to 2, where the variation N2P will be manifestly less than that at 1. At 3, the variation will be still_less; and at P of the meridian NyP, or eastern line of no variation, it will be nothing; because the north pole of the earth, N, and the real north-west pole, P, on the west side of the figure, are under one and the same meridian, PwNyP. After passing this meridian, an east variation would arise; and which, at 4, would amount to the angle P4N. At 5, the variation would be greater; and at o, it would be indicated by the angle PoN. Were the Professor's the only pole in the northern hemisphere, the variation at o would be only the small angle Noh. The scientific world are greatly indebted to Professor Hansteen for having lately made a laborious journey into Siberia, in order to elucidate important points in the useful science of magnetic variation. He is said to have made satisfactory observations at Irkutsk, in latitude 52°, and longitude 104° east. The north-west magnetic pole is considerably to the east of the meridian of

this place, and the east variation arising from its position, is much diminished by the action of the south-east pole, still nearer to the meridian of the above town in East Siberia. This would render the variation very little, but still it could not be ascribed to the imagined pole lying on the west side of the meridian of Irkutsk. All over the oriental quarter, and considerably beyond the equator, the variation is little, on account of the manifest counterac tion of the two poles, on the same side of the meridian of places under the above magnetic circumstances. Supposing the existence of a pole at h, it is evident, on known magnetic principles, that the needle at London could not point to the pole at P. It may be sufficient here to mention the result of experiments made with two magnets of equal power applied to the place of the real and of the supposed pole, in reference to a sensitive needle resting on the place of London. The variation given varied a few degrees, as might be expected; but the medium gave the angle LNn as the variation: but as the needle at London points in an angle somewhat greater than the calculated variation, NLP, it amounts to positive demonstration that the north-west is the only magnetic pole in the northern hemisphere; and similar reasoning applied to a similar figure for the southern hemisphere, would, mutatis mutandis, yield an equally conclusive result.

On the site of the magnetic pole the dipping needle will stand perpendicular, in continuation of the semi-diameter of the earth, and on some part of which, within the earth, the real pole, or magnetic power, is situated. After much consideration, it occurred to me that the depth of the pole within the hollow sphere of the earth, might be calculated trigonometrically. The difference of latitude between the place of the pole on the surface, and the place where a dip is taken, gave the angle at the centre. The complement of the angle of the dip to 90° gave the acute angle at the circumference. Having thus the three angles of a triangle within the earth, and the radius as one of the sides, the part of the other radius, intercepted between the true place of the pole and the centre of the earth, was calculated. By subtracting this from the semi-diameter on which the pole is situated,

the depth of the pole within the earth was obviously obtained. The place where the needle stands perpendicular I term the place of maximum magnetic intensity on the surface. It is the nearest point to the place of the pole within the earth, and moves on the surface in correspondence with the movement of the magnetic power in a small ellipsis within the earth. I may probably give you a figured detail of this valuable fact.

to

Sometimes the latitude and longitude cannot be had, and without these the variation cannot be calculated. Again, the lives of millions in future ages may and must depend on knowing and allowing for the attraction or repulsion of the needle by the guns and iron of a ship. This, called the local attraction of a ship, may be known on leaving a harbour, but alters with not only a change of a ship's head, but also under every change of situation of a ship, in moving to the north or south more especially. Having reason think, from an imperfect experiment, that the action of the iron did not extend much in any direction, I requested of a scientific friend to take the variation on a small stage suspended about twenty feet above the quarter-deck of a ship of war, saying that if it corresponded with the variation taken on shore, there would be a proof at once that the iron below had no effect on the needle above. I have seldom felt more gratified than in finding that the result agreed almost exactly. This shows that the difference between the variation taken above and on the quarterdeck will be the local attraction of a ship, thus enabled to sail in perfect security, when otherwise she might be ruuning to certain destruction. The true variation may also be ascertained, by taking the variation in a boat, a little astern of the ship, and comparing it with that taken on board. The cu

rious theory and rationale of this interesting natural object I may probably give briefly in some future paper.

JOHN MACDONALD.

Staffordshire MoorMr. URBAN, lands, July 14. THE HE announcement in your Magazine for March (p. 194), of a new edition of "Walton's Angler," has recalled to my recollection some notes of a pedestrian excursion to his

friend Charles Cotton's seat at Beresford, in the summer of 1824. They are in themselves of a trifling nature, but even trifles acquire value when they relate to scenes that have been "dignified by the presence of wisdom, bravery, or virtue;" and although no admirer of "The Complete Angler" can fail to be interested about a spot where honest Izaak often exercised his skill, or strayed and conversed with his son Cotton, in pureness and simplicity of heart, it is situated in so remote and wild a district, as to be comparatively but seldom visited; so that a brief description of its present appearance may not be deemed altogether inopportune.

Quitting Newcastle-under-Lyme on a fine morning in August, we crossed the smoky region of the Potteries, and taking the road to Leek, soon reached the village of Norton-in-the-Moors, formerly celebrated as the Gretna Green of the surrounding country, where impatient couples were linked together for life, without undergoing the tedious forms required in more punctilious places. But, alas! those days of extempore matches are over; Norton, like the Fleet, has lost its privileges; and they who now repair thither on a matrimonial excursion, must submit, as elsewhere, to the formality of bans, or the production of a license.

From Norton the road proceeds, through a district which becomes more barren at every step, to a village called in the maps Endon, but pronounced by the country-people Yan, in which, as in many other instances, they rather preserve the real name of the place, than are guilty of corrupting it; the old orthography being, I believe, Yendon. The Church, a modern structure, has nothing about it worthy of remark; but in the burialground, a grave-stone, which covers

the remains of Wm. Murball, Esq. late of Bagnall," exhibits this quaint inscription:

"Part of what I possessed is left to others, And what I gave away remains with me."

Of this person, a popular tradition in the neighbourhood is, that during the rebellion of 1745, a straggler from the Scottish army, on its retreat from Derby, took refuge in a shed near to his house, and being there discovered, was by him slain, flayed, and his skin conveyed to a tan-yard to be tanned;

but, not being able to get this performed, he took it home with him, and never after prospered. There is also a neat tomb in a field adjoining the Church-yard, said to be that of a "free-thinker," viz. " John Chenel, china-manufacturer, of Shelton, ob. 1721, æt. 65," whose motto, the inscription adds, was "Integrity and Honour."

About five miles beyond Endon, in a north-easterly direction, we arrived at Leek, the principal town of the Moorlands, containing about 5000 inhabitants, the majority of whom are engaged in the silk and ribbon manufacture, which is here carried on to a great extent. The Church is a handsome Gothic structure, and in the Church-yard stands a curious stone pillar, ornamented with fretwork and imagery, which Plot conjectures to be a Danish monument; it is figured and described in Gent. Mag. vol. L. p. 165. Leek is noted for the longevity of its inhabitants, and apparently not without reason, for I remarked that the grave-stones record eighty or ninety years as an age of quite common attainment theret.

After quitting Leek, the country becomes as wild as the most romantic fancy can desire; nothing meets the eye but huge masses of sterile crags, intersected by the channels of wintry floods, which sometimes rush from these eminences to the lowlands with terrific rapidity. Not a bush or tree is to be seen, and the only signs of vegetation which present themselves, are occasional patches of herbage in the vallies, inclosed by rude fences of limestone fragments, put together without cement. The thinly-scattered inhabitants subsist chiefly upon oat-cake, and a few oats are therefore occasionally sown, but they seldom or never completely ripen. Some idea of the steepness of the hills may be formed from Dr. Plot's description of Narrowdale, a place we visited on our way to Be

"I cannot vouch for this, d'ye see, I but tell it to you as 'twas told to me.' "The longevity of men in this county perhaps may be ascribed to their drinking of ale, Turnebus affirming that such is more wholsom and contributory to long life than wine, and that 'tis this makes many live to 100 years." (MS. note by Dr. Plot, in the copy of his History of Staffordshire," British Museum.)

resford: " In the northerly part of the Moore-lands (he says), the hills and boggs are such that a horse can scarce pass; and indeed many of the mountains, which they call roches, clouds, torrs, edges, cops, heads, &c. are hardly passable, some of them being of so vast a height, that in rainy weather I have frequently seen the tops of them above the clouds. Those of Narrowdale in particular, are so very lofty, that the inhabitants there, for that quarter of the year wherein the sun is nearest the tropic of Capricorn, never see it at all; and at length, when it does begin to appear, they never see it till about one by the clock, which they call thereabout the Narrowdale noon, using it proverbially when they would express a thing done late at noone." Altogether, a more desolate and barren tract is scarcely possible to imagine than that which we crossed, for about eight miles after quitting Leek, till we arrived at Alstonfield, on the verge of the Dove, where it assumes a somewhat better aspect. Here we halted at the sign of the George, and were entertained by our chatty hostess with anecdotes of the neighbourhood, and some excellent eggs and bacon, the only fare her larder afforded; after which, we took a hasty survey of the village, and the Church, a substantial stone building, fully justifying Viator's exclamation (Complete Angler, pt. ii.), "As I'm an honest man, a very pretty Church!" The two views of the exterior, in Major's Walton, though deficient in a few minutiæ, are upon the whole sufficiently correct. The interior, which is neatly fitted up with low oak pews, consists of a nave, side ailes, and chancel; there is a small organ, and a painting of Time and a Skeleton on each side of the altar. One of the pews, coloured blue, is said to have been that of the Cotton family; and Pitt, in his "History of Staffordshire," 1817, p. 243, assures us that the curious pulpit and reading-desk, on which is carved the date 1637, "were the gift of the celebrated Charles Cotton, the poet." If so, it was a most remarkable instance of precocious piety, that period only seven years old; but the "celebrated poet" having been at the fact is, that Walton's friend, in this as in fifty other instances, has been confounded with his father. Some extracts from the Register of this Church, relating to the Cottons, may

be seen in Gent. Mag. vol. xcv. pt. i. p. 581.

From Alstonfield, an easy quarter of an hour's walk brought us within view of Beresford Hall, lying embosomed in lofty trees, a green speck in the desert, while in front the delicate river Dove holds on its silvery course, but hidden from view by the lofty precipices which rise on either side of it. The trees I suppose are those mentioned by Viator, where he says of the Hall, It stands prettily, and here's wood about it too, but so young, it appears to be of your own planting" to which Piscator (Cotton) replies in the affirmative. The house, built I think by the Beresfords in the 16th century, is large and of respectable appearance. Major's view gives too mean an idea of it. That in Bagster's second edition," Linnell del., Greig sc." is much more faithful. The walls are constructed of coarse stone, the produce of the neighbourhood; the roof is tiled, and the chimneys are stone. Over the entrance is carved in lozenge the Beresford crest, a bear rampant, which is also painted in some of the windows. About 20 yards from the front, we passed through a gate in a substantial stone wall of recent erection, forming the boundary of a vegetable garden, and along a path, fenced on each side by a privet hedge, to the principal door, which opens into a large oldfashioned hall, having at one end a fire-place of ample dimensions, surmounted by antlers, and curiously carved work in oak. At the opposite extremity, three steps lead into a small room, called the Green parlour, part of which, partitioned off, still bears the name of "Squire Cotton's Study;' but the state of the apartment does not evince much veneration for his memory, the walls being decayed, and the window partly broken out. Opposite the entrance door, a staircase conducts to a lofty drawing-room, and a delightfully pleasant bed-room, the latter of which we nem. con. decided must be " my father Walton's apartment," in which Viator sleeps. There are various other chambers on this floor, but they are going fast to ruin, and several of them are in darkness, having the windows

"made up." Above them are garrets, from whence another flight of stairs, or a ladder rather, gives access to the roof, part of which is flat, and surrounded by balus

trades; but they are much decayed, and in a tottering condition. The view here is remarkably pleasant. In front, the house is sheltered from the Moorland blasts by a steep hill, and to the left by another, on which are the ruins of a stone building called the Temple, and here was the bowlinggreen, to which, in the second part of "The Complete Angler," Cotton calls the attention of his friend. Far below these hills runs the Dove, to which descending by a steep and somewhat hazardous winding path, we about half way down, to a dark, damp hole in the rock, dignified by the title of " Squire Cotton's Grotto," a spot which, in his fine stanzas on Retirement, he has rendered celebrated by those well-known lines, commencing "O my beloved Cave, from Dog-star's heat And all anxieties, a safe retreat!"

came

It might be a safe retreat, but could scarcely be a pleasant one; nor, if we may credit tradition, did it suffice to exclude those "anxieties" with which poor Cotton appears to have been incessantly harassed. Mr. Davies, in his "Historical and Descriptive View of Derbyshire," 1811, p. 502, gives the induced him to seek refuge in it; but following account of the motives which I believe the "offence" he alludes to was nothing more heinous than that of forgetting to pay his tradesmen's debts, nor the officers of justice" anything more formidable than a couple of bailiffs:

"In one of the rocks which hang over the river, is a small cavity, in which Mr. Cotton is said to have eluded the officers of justice, after some offence of which he had been guilty. The depth of it is about 15 yards, but even in this small space are several windings, which render it difficult of access, and well adapted for the purpose of

concealment."

Arrived at the termination of the descent, we found ourselves on the banks of the far-famed Dove, which though at its source among the moors, six or seven miles higher, a dark-coloured stream, is rendered beautifully bright and limpid ere it arrives at this place, by numerous tributary springs received on the way. Adjoining this spot is the chief scene of action in pt. ii. of "The Complete Angler," viz. Pike Pool, Major's two views of which yield a clear idea of the scene, and the remarkable Rock or Pike, from which