shire.

Aberdeen reform, reported on the case of Aberdeen. From this report, it appears that the town lands, which were forAberdeen. merly very extensive, had been alienated, with the reservation of very inadequate feu-duties. The fishings of the Dee and Don, now producing about 10,000l. ayear, were alienated for an annual feu-duty of 271. 78. 3d. The lands belonging to charitable establishments, of which the magistrates were only trustees, had been sold, and the proceeds applied to the city expenditure. The amount due to the various charities when the town became insolvent was about 80,000l. for which the charities receive only four per cent. The sum of 127,000l. had been borrowed under an act of Parliament, for building wet and graving docks, but the works were never executed. These, and other large sums borrowed by the magistrates, appear to have been dissipated in some ill-conducted plans of local improvement, which have made very trifling returns; and not only the citizens were ignorant of the burdens which were thus accumulating over their property, but very few of the magistrates themselves seem to have fully understood the state of the town's affairs. A statement, purporting to be an abstract of the town's affairs, was annually exhibited to the burgesses at Michaelmas; but this appears rather to have been for the purpose of deception than information; for, in 1810, when the town actually owed upwards of 140,000l. the whole debt, according to the statement shewn to the burgesses, was only 6874l. 175. 4d. The facts brought to light by the insolvency of Aberdeen, have roused the burgesses of most of the large burghs in Scotland to attempt some reform in the municipal government. Whether they shall succeed, may depend on circumstances; but it cannot be doubted that the existing system has a great tendency to encourage a wasteful expenditure, to repress public spirit, and to create jealousies between the magistrates and those whose welfare it should be their study to promote.

From a round bill, at the west end of the city, flow two springs, one of pure water, and the other of a quality resembling the German Spa. The population of Aberdeen in 1811 was 21,639. Aberdeen, with Aberbrothick, Brechin, Montrose, and Inverbervy, re. turns one member to parliament.

ABERDEENSHIRE, an extensive county in Scotland, is bounded on the north and east by the German ocean; on the south by the counties of Kincardine, Angus, and Perth; and on the west by Banff, Murray, and Inverness shires. It extends in length about 85 miles, from south-west to north-east, and about 40 in breadth, from the mouth of the river Dee to where it is bounded by the shire of Banff. Its extent in be estimated at 1986. It compresquare miles may hends the districts of Marr, Garioch, Aberdeen Proper, and great part of Buchan. The district of Marr, which may be considered as the centre of Scotland, is wild, rugged, and mountainous; some of the hills rising with precipitous sides, to the height of 2000 feet above the level of the sea. The sides of the hills are covered with extensive natural forests; in many places impenetrable to human footsteps. Buchan is less hilly; but very barren, bleak and inhospitable to the view. The rest of the country is more fertile, having a gradual descent from the central district eastward to the

sea.

The coast is in general very bold and rocky.

shire.

The Boilers or Bullers of Buchan, arrest the attention Aberdeenof all strangers, by their stupendous craggy precipices. The soil, in so extensive a district, is as various as can be well supposed. The state of agriculture in the interior parishes of the county is very rude; but the example of many patriotic proprietors is producing wonders even in the most barren soils. Prejudices in husbandry, when deeply rooted, are with difficulty overcome; but even these are yielding to a more regular and modern systém. A navigable canal, extending 18 miles, from the harbour of Aberdeen to Inverury, was opened in 1807. It is 23 feet wide, by 3 feet 9 inches deep; and is raised to the height of 168 feet above low water mark by 17 locks. The principal rivers of Aberdeenshire are, the Dee and Don, the Ythan, the Ugie, and the Cruden. The Deveron also forms its boundary with Banffshire for many miles. All the rivers have been long celebrated for the excellence of the salmon with which they abound. The rents of the fishings are estimated at 2480l. per annum, and the produce at upwards of 10,000l. Besides the fishings of the rivers, the sea coast of Aberdeenshire abounds with all kinds of excellent fish; and a number of fishing vessels are fitted out from the sea ports of the county, particularly Peterhead and Fraserburgh. Under the article of fisheries, we may mention the celebrated pearl fishing in the river Ythan. In this river some pearls have been found, which sold singly so high as 21. and 31. With regard to mineralogy, little wealth of that description has hitherto been found in this county. The granite quarries are the most valuable articles. From those in the neighbourhood of Aberdeen, 12,000 tons and upwards are annually exported to London, the value of which may be estimated at about 8400l. There are several quarries in the parish of Aberdour, which yield excellent millstones. There is a quarry of blue slate wrought in the parish of Culsalmond, and a vein of manganese in the neighbourhood of Old Aberdeen. The county abounds with limestone; but, from the want of coal, it cannot be wrought to much advantage, except near a sea port. In Old Machar and Old Deer parishes, about 55,000 bolls of lime are annually burnt, valued at 27 50l. Some kelp is made on the coast, the value of which must be considerable. Plumbago, amethysts, emeralds, agates, asbestos, talc, mica, schistus, and other curious minerals, are found in many parts of the county. The principal manufacture carried on in the county, is the knitting of stockings and hose, in which all the women, and most of the old men and boys, are employed the greater part of the year. The other manufactures are too trifling to deserve particular notice. Aberdeenshire contains three royal boroughs; ABERDEEN, KINTORE, and INVERURY: and several large and handsome towns; as Peterhead, Fraserburgh, Huntly, and Old Meldrum. It is divided into 85 parishes.

The following account of the population of Aberdeenshire, at two different periods, is taken from the Statist. Hist. of Scotland.

Deer, New

25 Deer, Old

2813

1125

30 Ellon

Fintray

905

Forbes

456

85 Udney

Population in 1811
See ABERDEENSHIRE, SUPPLEMENT.

ABERDOUR, a small town in Fifeshire, Scotland, on the frith of Forth, about ten miles north-west of Edinburgh. In old times it belonged to the Viponts; in 1126 it was transferred to the Mortimers by marriage, and afterwards to the Douglases. William, lord of Liddesdale, surnamed the Flower of Chivalry, in the reign of David II. by charter conveyed it to James Douglas, ancestor of the present noble owner the earl of Morton. The monks of Inchcolm had a grant for a burial place here from Allan de Mortimer, in the reign of Alexander III. The nuns, usually styled the Poor Clares, had a convent at this place.

ABERFORD, a market town in the west riding of Yorkshire, stands in a bottom; and is about a mile in length, and pretty well built. It is near a Roman road, which is raised very high, and not far from the river Cock; between which and the town there is the foundation of an old castle still visible. It is 181 miles north-by-west from London. W. Long. 2. 45. N. Lat. 55. 52.

ABERGAVENNY, a large, populous, and flourishing town in Monmouthshire, seated at the confluence of the rivers Usk and Gavenny. It has a fine bridge over the Usk, consisting of fifteen arches; and being a great thoroughfare from the west part of Wales to Bath, Bristol, Gloucester, and other places, is well furnished with accommodation for travellers. It is surrounded with a wall, and had once a castle. It carries on a considerable trade in flannels, which are brought hither for sale from the other parts of the county. It is 142 miles distant from London. W. Long. 3. N. Lat. 51. 47. Abergavenny appears to have been the Gibbanium of Antoninus, and the town of Usk his Burrium. Population 2815 in 1811.

ABERNETHY, JOHN, an eminent dissenting minister, was the son of Mr John Abernethy, a dissenting minister in Coleraine, and was born there on the 19th of October 1680. When about nine years of age he was separated from his parents, his father being ob

flight of the bird is more rapid, with respect to the flight of the shot." In this way of considering the matter, the flight of the bird represents the motion of the earth, and the flight of the shot represents the motion of the ray of light.

Mr Clairaut too, in the Mem. de l'Acad. des. Sciences for the year 1746, illustrates this effect in a familiar way, by supposing drops of rain to fall rapidly and quickly after each other from a cloud, under which a person moves with a very narrow tube; in which case it is evident that the tube must have a certain inclina tion, in order that a drop which enters at the top, may fall freely through the axis of the tube, without touching the sides of it; which inclination must be more or less according to the velocity of the drops in respect to that of the tube; then the angle made by the direction of the tube and of the falling drops, is the aberration arising from the combination of those two motions.

Abernethy, liged to attend some public affairs in London; and his Aberration. mother, to shelter herself from the mad fury of the Irish rebels, retiring to Derry, a relation who had him under his care, having no opportunity of conveying him to her, carried him to Scotland; and thus he escaped the hardships and dangers of the siege of Derry, in which Mrs Abernethy lost all her other children. He afterwards studied at the university of Glasgow, where he remained till he took the degree of master of arts; and, in 1708, he was chosen minister of a dissenting congregation at Antrim, in which situation he continued above 20 years. About the time of the Bangorian controversy (for which see HOADLEY), a dissension arose among his brethren in the ministry at Belfast, on the subject of subscription to the Westminster Confession of Faith. In this controversy he became a leader on the negative side, and incurred the censure of a general synod. The agitation of parties began to be also felt among the members of his congregation. Many of them deserted him; which induced him to accept of an invitation to settle in Dublin, where his preaching was much admired. Here he continued for ten years, respected and esteemed. But his labours were terminated by a sudden attack of the gout in the head, to which he had been subject; and he died in December 1740, in the 60th year of his age. His writings, as was his character, are distinguished for candour, liberality, and manly sentiment. He published a volume of sermons on the Divine Attributes; after his death a second volume was published by his friends; and these were succeeded by four other volumes on different subjects: all of which have been greatly admired.

ABERNETHY, a small town in Stratbern, a district of Perthshire in Scotland, situated on the river Tay, a little above the mouth of the Erne. It is said to have been the seat of the Pictish kings; and was afterwards the see of an archbishop, which was afterwards transferred to St Andrew's. In the churchyard of Abernethy, there is a tower of singular construction. It is of a circular form, is 74 feet in height, and 48 feet in circumference. The tower at Brechin is the only one of a similar structure in Scotland. The researches of the antiquarian have hitherto failed in discovering the uses of these insulated buildings. It has been supposed that they are of Pictish origin, and that they were intended as places of confinement for religious devotees in performing penance, and hence they have been denominated towers of repentance. Population 1635 in 1811.

ABERRATION, in Astronomy, an apparent motion of the celestial bodies, produced by the progressive motion of light, and the earth's annual motion in her orbit.

This effect may be explained and familiarized by the motion of a line parallel to itself, much after the manner that the composition and resolution of forces are explained..

M. de Maupertuis, in his "Elements of Geography, gives a familiar and ingenious idea of the aberration, in this manner: "It is thus," says he, "concerning the direction in which a gun must be poiuted to strike a bird in its flight: instead of pointing it straight to the bird, the fowler will point a little before it, in the path of its flight, and that so much the more as the

This discovery, which is one of the brightest that have been made in the present age, we owe to the accuracy and ingenuity of the late Dr Bradley, astronomer royal; to which he was occasionally led by the result of some observations which he had made with a view to determine the annual parallax of the fixed stars, or that which arises from the motion of the earth in its annual orbit about the sun.

The annual motion of the earth about the sun had been much doubted, and warmly contested. The defenders of that motion, among other proofs of the reality of it, conceived the idea of adducing an incontestable one from the annual parallax of the fixed stars, if the stars should be within such a distance, or if instruments and observations could be made with such ac. curacy, as to render that parallax sensible. And with this view various attempts have been made. Before the observations of M. Picard, made in 1672, it was the general opinion, that the stars did not change their position during the course of a year. Tycho Brahe and Ricciolus fancied that they had assured themselves of it from their observations; and from hence they concluded that the earth did not move round the sun, and that there was no annual parallax in the fixed stars. M. Picard, in the account of his Voyage d' Uranibourg, made in 1672, says that the pole star, at different times of the year, has certain variations, which he had observed for about 10 years, and which amounted to about 40" a year from whence some, who favoured the annual motion of the earth, were led to conclude that these variations were the effect of the parallax of the earth's orbit. But it was impossible to explain it by that parallax; because this motion was in a manner contrary to what ought to follow only from the motion of the earth in her orbit.

In 1674 Dr Hook published an account of observations which he said he had made in 1669, and by which he had found that the star y Draconis was 23" more northerly in July than in October: observations which, for the present, seemed to favour the opinion of the earth's motion, although it be now known that there could not be any truth or accuracy in them.

Flamsteed having observed the pole star with his mural quadrant, in 1680 and the following years, found that its declination was 40" less in July than in December; which observations, although very just, were

yet

Aberration. yet, however, improper for proving the annual parallax ; and he recommended the making of an instrument of 15 or 20 feet radius, to be firmly fixed on a strong foundation, for deciding a doubt which was otherwise not soon likely to be brought to a conclusion.

In this state of uncertainty and doubt, then, Dr Bradley, in conjunction with Mr Samuel Molineux, in the year 1725, formed the project of verifying, by a series of new observations, those which Dr Hook had communicated to the public almost 50 years before. And as it was his attempt that chiefly gave rise to this, so it was his method in making the observations, in some measure, that they followed; for they made choice of the same star, and their instrument was constructed upon nearly the same principles: but had it not greatly exceeded the former in exactness, they might still have continued in great uncertainty as to the parallax of the fixed stars. For this, and many other convenient and useful astronomical instruments, philosophers are indebted to the ingenuity and accuracy of Mr Graham. The success of the experiment evidently depending so much on the accuracy of the instrument, this became a leading object of consideration. Mr Molineux's apparatus then having been completed, and fitted for observing, about the end of November 1725, on the third day of December following, the bright star in the head of Draco, marked by Bayer, was for the first time observed, as it passed near the zenith, and its situation carefully taken with the instrument. The like observations were made on the fifth, eleventh, and twelfth days of the same month; and there appearing no material difference in the place of the star, a farther repetition of them, at that season, seemed needless, it being a time of the year in which no sensible alteration of parallax, in this star, could soon be expected. It was therefore curiosity that chiefly urged Dr Bradley, who was then at Kew, where the instrument was fixed, to prepare for observing the star again on the 17th of the same month; when, having adjusted the instrument as usual, he perceived that it passed a little more southerly this day than it had done before. Not suspecting any other cause of this appearance, it was ascribed to the uncertainty of the observations, and that either this, or the foregoing, was not so exact as had been supposed. For which reason they proposed to repeat the observation again, to determine from what cause this difference might proceed and upon doing it, on the 20th of December, the doctor found that the star passed still more southerly than at the preceding observation. This sensible alteration surprised them the more, as it was the contrary way from what it would have been, had it proceeded from an annual parallax of the star. But being now pretty well satisfied, that it could not be entirely owing to the want of accuracy in the observations, and having no notion of any thing else that could cause such an apparent motion as this in the star; they began to suspect that some change in the materials or fabric of the instrument itself might have occasioned it. Under these uncertainties they remained for some time; but being at length fully convinced, by several trials, of the great exactness of the instrument; and finding, by the gradual increase of the star's distance from the pole, that there must be some regular cause that produced it; they took care to examine very nicely, at the time of 3

each observation, how much the variation was; til! Aberration. about the beginning of March 1726, the star was found to be 20" more southerly than at the time of the first observation: it now indeed seemed to have arrived at its utmost limit southward, as in several trials, made about this time, no sensible difference was observed in its situation. By the middle of April it appeared to be returning back again towards the north; and about the beginning of June, it passed at the same distance from the zenith, as it had done in December, when it was first observed.

From the quick alteration in the declination of the star at this time, increasing about one second in three days, it was conjectured that it would now proceed northward, as it had before gone southward, of its present situation; and it happened accordingly; for the star continued to move northward till September following, when it again became stationary; being then near 20" more northerly than in June, and upwards of 39" more northerly than it had been in March. From September the star again returned towards the south, till, in December, it arrived at the same situation in which it bad been observed twelve months before, allowing for the difference of declination on account of the precession of the equinox.

This was a sufficient proof that the instrument had not been the cause of this apparent motion of the star; and yet it seemed difficult to devise one that should be adequate to such an unusual effect. A nutation of the earth's axis was one of the first things that offered itself on this occasion; but it was soon found to be insufficient; for though it might have accounted for the change of declination in y Draconis, yet it would not at the same time accord with the phenomena observed in the other stars, particularly in a small one almost opposite in right ascension toy Draconis, and at about the same distance from the north pole of the equator: for though this star seemed to move the same way, as a nutation of the earth's axis would have made it; yet changing its de, clination but about half as much as y Draconis in the same time, as appeared on comparing the observations of both made on the same days, at different seasons of the year, this plainly proved that the apparent motion of the star was not occasioned by a real nutation; for had this been the case, the alteration in both stars would have been nearly equal.

The great regularity of the observations left no room to doubt, but that there was some uniform cause by which this unexpected motion was produced, and which did not depend on the uncertainty or variety of the seasons of the year. Upon comparing the observations with each other, it was discovered that, in both the stars above mentioned, the apparent difference of declination from the maxima, was always nearly proportional to the versed sine of the sun's distance from the equinoctial points. This was an inducement to think that the cause, whatever it was, had some relation to the sun's situation with respect to those points. But not being able to frame any hypothesis, sufficient to account for all the phenomena, and being very desirous to search a little farther into this matter, Dr Bradley began to think of erecting an instrument for himself at Wanstead; that, having it always at hand, he might with the more ease and certainty inquire into the laws of this new motion. The consideration likewise of being

Aberration being able, by another instrument, to confirm the truth of the observations hitherto made with that of Mr Molineux, was no small inducement to the undertaking; but the chief of all was, the opportunity he should thereby have of trying in what manner other stars should be affected by the same cause, whatever it might be. For Mr Molineux's instrument being originally designed for observing Draconis, to try whether it had any sensible parallax, it was so contrived, as to be capable of but little alteration in its direction; not above seven or eight minutes of a degree: and there being but few stars, within half that distance from the zenith of Kew, bright enough to be well observed, he could not, with his instrument, thoroughly examine how this cause affected stars that were differently situated, with respect to the equinoctial and solstitial points of the ecliptic.

These considerations determined him; and by the contrivance and direction of the same ingenious person, Mr Graham, his instrument was fixed up the 19th of August 1727. As he had no convenient place where he could make use of so long a telescope as Mr Molineux's, he contented himself with one of but little more than half the length, namely of 12 feet and a half, the other being 24 feet and a half long, judging from the experience he had already had, that this radius would be long enough to adjust the instrument to a sufficient degree of exactness: and he had no reason afterwards to change his opinion; for by all his trials he was very well satisfied, that when it was carefully rectified, its situation might be securely depended on to half a second. As the place where his instrument was hung, in some measure determined its radius; so did it also the length of the arc or limb, on which the divisions were made, to adjust it: for the arc could not conveniently be extended farther, than to reach to about 6 degrees on each side of the zenith. This however was sufficient, as it gave him an opportunity of making choice of several stars, very different both in magnitude and situation; there being more than two hundred, inserted in the British Catalogue, that might be observed with it. He needed not indeed to have extended the limb so far, but that he was willing to take in Capella, the only star of the first magnitude that came so near his zenith.

His instrument being fixed, he immediately began to observe such stars as he judged most proper to give him any light into the cause of the motion already mentioned. There was a sufficient variety of small ones, and not less than twelve that he could observe through all seasons of the year, as they were bright enough to be seen in the day time, when nearest the sun. He bad not been long observing, before he perceived that the notion they had before entertained, that the stars were farthest north and south when the sun was near the equinoxes, was only true of those stars which are near the solstitial colure. And after continuing his observations a few months, he discovered what he then apprehended to be a general law observed by all the stars, namely, that each of them be came stationary, or was farthest north or south, when it passed over his zenith at six of the clock, either in the evening or morning. He perceived also that whatever situation the stars were in, with respect to the cardinal points of the ecliptic, the apparent motion of

every one of them tended the same way, when they Aberration. passed his instrument about the same hour of the day or night; for they all moved southward when they passed in the day, and northward when in the night; so that each of them was farthest north when it came in the evening about six of the clock, and farthest south when it came about six in the morning.

Though he afterwards discovered that the maxima, in most of these stars, do not happen exactly when they pass at those hours; yet, not being able at that time to prove the contrary, and supposing that they did, he endeavoured to find out what proportion the greatest alteratious of declination, in different stars, bore to each other; it being very evident that they did not all change their inclination equally. It has been before noticed, that it appeared from Mr Molineux's observations, that Draconis changed its declination above twice as much as the before-mentioned small star that was nearly opposite to it; but examining the matter more nicely, he found that the greatest change in the declination of these stars, was as the sine of the latitude of each star respectively. This led him to suspect that there might be the like proportion between the maxima of other stars; but finding that the observations of some of them would not perfectly correspond with such an hypothesis, and not knowing whether the small difference he met with might not be owing to the uncertainty and error of the observations, he deferred the farther examination into the truth of this hypothesis, till he should be furnished with a series of observations made in all parts of the year; which would enable him not only to determine what errors the ohservations might be liable to, or how far they might safely be depended on; but also to judge, whether there had been any sensible change in the parts of the instrument itself.

When the year was completed, he began to examine and compare his observations; and having satisfied himself as to the general laws of the phenomena, he then endeavoured to find out the cause of them. He was already convinced that the apparent motion of the stars was not owing to a nutation of the earth's axis. The next that occurred to him, was an alteration in the direction of the plumb-line, by which the instrument was constantly adjusted; but this, upon trial, provided insufficient. Then he considered what refraction might do; but here also he met with no satisfaction. At last, through an amazing sagacity, he conjectured that all the phenomena hitherto mentioned, proceeded from the progressive motion of light, and the earth's annual motion in her orbit: for he perceived, that if light were prepagated in time, the apparent place of a fixed object would not be the same when the eye is at rest, as when it is moving in any other direction but that of the line passing through the object and the eye; and that when the eye is moving in different directions, the apparent place of the object would be different. (Hutton's Math. Dict.).

ABERRATION, in Optics, the deviation or dispersion of the rays of light, when reflected by a speculum, or refracted by a lens, which prevents them from meeting or uniting in the same point, called the geometrical focus, but are spread over a small space, and produce a confusion of images. There are two species of aberration distinguished by their different causes;

the