6th March in 1716, 1777, 1843, 1867, and 1868; on the 9th September in 1776, 1827, 1835, 1866, 1868, 1872, and on the 29th in 1828, 1840, 1851, 1852, 1870, and 1872. This conclusion, however, is not supported by systematic investigation. A considerable catalogue of aurora was divided into decennial periods, and it was found that the maxima of one period rarely coincided with those of others, and that the larger the number of years taken into account the less prominent the maxima appeared,-evident proof that they were only accidental. It may be, however, that if only prominent aurora had been considered, more periodicity might have been found, or that the periodicity is constant for very short periods only.

Although no daily periodicity can be affirmed, there are two well-marked annual maxima in March and October, of which the latter is the greater, and two minima-the greater in June and the less in January. In this respect the aurora differs from the sporadic meteors, which have a maximum in autumn and a minimum in spring. It also differs from meteors in the hours of its appearance, the former being most frequent before and the latter after midnight. Meteoric

esis.

on

66

Trans. 1790, pp. 32, 47, 101; Dalton's Meteorological Observations, 1793, pp. 54, 153; Chiminello, "On a Luminous Arch," Soc. Ital., vii. 153; Loomis, "Electrical and Magnetic Rela tions," Sill. Jour. 2d ser., xxxii. 324, xxxiv. 34, Sept., 1870, Catalogue, Geog. dist., Sun spots," &c., ibid., 3d ser. v. 245, &c.; B. V. Marsh, "Electrical Theory," ibid., 3d ser., cxlvi. 284, 569; Galle and Sirks on "Crown," ibid., cxlvi. 133, xxxi. 311; Oettingen and Vogel on "Spectrum," Pogg. Ann., exlix. 112; Silbermann, Comptes Rendus, 1xviii. 1049, 1120, 1140, 1164; Prof. Fritz, "Geog. Distrib.," Petermann's Mitt., Oct., 1874; Zehfuss, Physikalische Theorie, Adelman, Frankfort; Balfour Stewart, Phil. Mag. 4th ser., xxxix. 59; A. S. Davis, ibid., xl. 33; C. Piazzi Smyth, Ed. Ast. Observations, xiii. R. 85, Phil. Mag., 4th ser., xlix., Jan., 1875; A. S. Herschel, Nat., iii. 6; Sir W. R. Grove and J. R. Capron, ibid., 28: Webb, Glaisher, &c.; "Daylight Aurora," ibid., 104, 126, 348, 510, iv. 209, &c.; Heis, "Auroras at Melbourne," ibid., iv. 213; Prof. C. A. Young, ibid., iv. 345; Kirkwood, " Periodicity," ibid., iv. 505; H. R. Procter, ibid., iii. 7, 346, &c.; P. E. Chase, "On Auroras and Gravitating Currents," ibid., iv. 497; H. A. Newton, "Height," Sill. Jour. 2d ser. xxxix. 286, 371; Angström, Pogg. Ann. ("Jubelband") and Nat., x. 211; J. R. Capron, "Spectrum," Phil. Mag., 4th ser., xlix., April, 1875. (H. R. P.) Although the electric hypothesis is the one AURUNGÁBÁD, or AURANGABAD, a city of India, in generally accepted by scientific men, it is only the native state of Haidarábád, or the Nizam's dominions, Hypoth- fair to allude to one that has been recently pro-situated in 19° 51′ N. lat., and 75° 21′ E. long., 138 miles posed independently by Dr. Zehfuss (Physikalische from Púna, 207 from Bombay via Púna, and 270 from Theorie, Adelman, Frankfort) and by H. J. H. Groneman Haidarábád. It was founded about the year 1620, under of Gröningen (Astronomische Nachrichten, No. 2010-2012). According to this view, the light of the aurora is caused the name of Gurka, by Malik Ambar, an Abyssinian, who had risen from the condition of a slave to great influence, by clouds of ferruginous meteoric dust, which is ignited by Subsequently it became the capital of the Moghul confriction with the atmosphere. Groneman has shown that these might be arranged along the magnetic curves by quests in the south of India. Aurungzebe made it the seat action of the earth's magnetic force during their descent, and gave it the name of Aurungábád. It thus grew into of his government during his viceroyalty of the Deccan, and that their influence might produce the observed mag- the principal city of an extensive province of the same netic disturbances. The arches may be accounted for by the effects of perspective on columns suddenly terminated name, stretching westward to the sea, and comprehending at a uniform height by increase of atmospheric density, the northern division of the presidency of Bombay. Aurungnearly the whole of the territory now comprised within while the correspondences with iron lines in its spectrum ábád long continued to be the capital of the succession of are sufficiently close to favor the idea. Ferruginous particles have been found in the dust of the Polar regions (E. potentates bearing the modern title of Nizam, after those A. Nordenskiold, Ast. Nach., 1874, 154), but whether chiefs became independent of Dehli. They abandoned it subsequently, and transferred their capital to Haidarábád, they are derived from stellar space or from volcanic erup- when the town at once began to decline. It is now greatly tion is uncertain. The yearly and eleven-yearly periodicity fallen from its ancient grandeur. The city is but halfof aurora tends to support the theory, but it is a formidable difficulty that, while shooting stars are more frequent in peopled, and is half in ruins, presenting everywhere the the morning, or on the face of the earth which is directed ulation is, however, still considerable, and in the bázár, melancholy appearances of desertion and decay. The popforwards in its orbit, the reverse is the case with aurore. which is very extensive, various rich commodities, particu Groneman meets this difficulty by supposing that in the larly silks and shawls, are exposed for sale. The walls of first case the velocity may be too great to allow of arrange- the town are similar in their construction to those of all ment by the earth's magnetic force, and that, consequently, the other cities in this quarter of India, being rather low, only diffused light can be produced. He accounts for its unfrequency in equatorial regions by the weakness of the earth's magnetic force, and the fact that, when it does occur, the columns must be parallel to the earth's surface. Without pronouncing in favor of this hypothesis, it must be admitted that it furnishes a plausible explanation of the phenomenon, although we have no evidence that meteoric dust, even if it exists, would produce the observed spectrum, and, as has been already remarked, the iron coincidences are of little weight.

Although we must confess that the causes of the aurora are very imperfectly explained, we may hope that the rapid progress which the last few years have witnessed in bring ing terrestrial magnetism under the domain of cosmical laws may soon be extended to the aurora, and that we shall see in it fresh evidence that the same forces which cause hurricanes in the solar atmosphere thrill sympathetically to the furthest planets of our system in waves, not only of light and heat, but of magnetism and electricity.

Bibliog raphy.

The following is a list of the most important papers, treatises, and works on this subject :-Berlin Mem. 1710, i. 131; Halley, Phil. Trans. 1716, 1719, xxix. 406, xxx. 584; Hearne, Phil. Trans. xxx. 1107; Langworth, Huxham, Hallet, and Callendriui, Phil. Trans. xxxiv. 132, 150; Mairan, Traité de l'Aurore Boréale, 1733, 1754; Weidler, De Aurora Boreali, 4to; Wargentin, Phil. Trans. 1751, p. 126, 1752, p. 169, 1753, p. 85; Bergmann, Schw. Abh., 200, 251; Wiedeburg, Ueber die Nordlichter, 8vo, Jena, 1771; Hüpsch, Untersuchung des Nordlichts, 8vo, Cologne, 1778; Van Swinden, Recueil de Mémoires, Hague, 1784; Cavallo, Phil. Trans. 1781, p. 329; Wilke, "Von den Neuesten Erklärungen des Nordlichts," Schwedisches Mus., 8vo, Wismar, 1783; Hey, Wollaston, Hutchinson, Franklin, Pigott, and Cavendish, Phil.

with round towers.

AURUNGZEBE, one of the greatest of the Moghul emperors of Hindustan, was the third son of Shah Jehan, and was born in October, 1618. His original name, Mahomet, was changed by his father, with whom he was a favorite, into Aurungzebe, meaning ornament of the throne, and at a later time he assumed the additional titles of Mohi-eddin, reviver of religion, and Alam-gir, conqueror of the world. At a very early age, and throughout his instilled into him in the course of his education under some whole life, he manifested profound religious feeling, perhaps of the strictest Mahometan doctors. He was employed, while very young, in some of his father's expeditions into the country beyond the Indus, gave promise of considerable military talents, and was appointed to the command of an army directed against the Usbeks. In this campaign he was not completely successful, and soon after was transferred to the army engaged in the Deccan. Here he gained several victories, and in conjunction with the famous general, Meer Jumla, who had deserted from the king of Golconda, he seized and plundered the town of Haidarábád, which belonged to that monarch. His father's express orders prevented Aurungzebe from following up this success, and, not long after, the sudden and alarming illness of Shah Jehan turned his thoughts in another direction. Of Shah Jehan's four sons, the eldest, Dara, a brave and honorable prince, but disliked by the Mussulmans on account of his liberality of thought, had a natural right to the throne. Accordingly, on the illness of his father, he at once seized the reins of government and established himself at Dehli. The second son, Soojah, governor of Bengal, a dissolute and sensual prince, was dissatisfied, and raised an army to dispute the throne with

Dara. The keen eye of Aurungzebe saw in this conjunc- | indeed possible, till the advance of the study of anatomy ture of events a favorable opportunity for realizing his own led to correct ideas regarding the locality, structure, and ambitious schemes. His religious exercises and temperate uses of the various organs of the body, and to the alterahabits gave him, in popular estimation, a great superiority tions produced in them by disease. In 1761 Auenbrugger over his brothers, but he was too politic to put forward his of Vienna introduced the art of percussion in reference claims openly. He made overtures to his younger brother more especially to diseases of the chest. This consisted Murad, governor of Guzerat, representing that neither of in tapping with the fingers the surface of the body, so as their elder brothers was worthy of the kingdom, that he to elicit sounds by which the comparative resonance of the himself had no temporal ambition, and desired only to subjacent parts or organs might be estimated. Auenbrugplace a fit monarch on the throne, and then to devote ger's method attracted but little attention, till Corvisart. himself to religious exercises and make the pilgrimage to in 1808, demonstrated its great practical importance; Mecca. He therefore proposed to unite his forces to those and then its employment in the diagnosis of affections of of Murad, who would thus have no difficulty in making the chest soon became general. Percussion was originally himself master of the empire while the two elder brothers practised in the manner above mentioned (immediate perwere divided by their own strife. Murad was completely cussion), but subsequently the method of mediate percusdeceived by these crafty representations, and at once sion was introduced by Piorry, and is that now largely accepted the offer. Their united armies then moved north-adopted. It is accomplished by placing upon the spot to ward. Meanwhile Shah Jehan had recovered, and though Dara resigned the crown he had seized, the other brothers professed not to believe in their father's recovery, and still pressed on. Soojah was defeated by Dara's son, but the imperial forces under Jesswunt Singh were completely routed by the united armies of Aurungzebe and Murad. Dara in person took the field against his brothers, but was defeated and compelled to fly. Aurungzebe then, by a clever stroke of policy, seized the person of his father, and threw him into confinement, in which he was kept for the remaining eight years of his life. Murad was soon removed by assassination, and the way being thus cleared, Aurungzebe, with affected reluctance, ascended the throne in August, 1658. He quickly freed himself from all other competitors for the imperial power. Dara, who again invaded Guzerat, was defeated and closely pursued, and was given up by the native chief with whom he had taken refuge. He was brought to Dehli, exhibited to the people, and assassinated. Soojah, who had been a second time defeated near Allahabad, was attacked by the imperial forces under Meer Jumla and Mahomet, Aurungzebe's eldest son, who, however, deserted and joined his uncle. Soojah was defeated and fled to Aracan, where he perished; Mahomet was captured, thrown into the fortress of Gwalior, and died after seven years' confinement. No similar contest disturbed Aurungzebe's long reign of forty-six years, which has been celebrated, though with doubtful justice, as the most brilliant period in the history of Hindustan. The empire certainly was wealthy and of enormous extent, for there were successively added to it the rich kingdoms of Bajapore and Golconda, and the barren province of Assam, but it was internally decaying, and ready to crumble away before the first vigorous assault. Two causes principally had tended to weaken the Moghul power. The one was the intense bigotry and intolerant policy of Aurungzebe, which had alienated the Hindus and roused the fierce animosity of the haughty Rajputs. The other was the rise and rapid growth of the Mahratta power. Under their able leader, Sevaji, these daring freebooters plundered in every direction, nor could all Aurungzebe's efforts avail to subdue them. At the close of the long contests between them, the Moghul power was weaker, the Mahratta stronger than at first. Still the personal ability and influence of the emperor were sufficient to keep his realms intact during his own life. His last years were embittered by remorse, by gloomy forebodings, and by constant suspicion, for he had always been in the habit of employing a system of espionage, and only then experienced its evil effects. He died, on the 21st February, 1707, at Ahmadnagar, while engaged on an extensive but unfortunate expedition against the Mahrattas.

AUSCHWITZ, or OSWIECIM, a town in Galicia, Austria, on the right bank of the Sola, a tributary of the Wechsel, 33 miles W.S.W. of Cracow. It has a population of upwards of 3800, and carries on a trade in salt. Previous to the first partition of Poland in 1773, it was the seat of a dukedoni, which had been united by Sigismund Augustus with the duchy of Zator in 1564.

AUSCULTATION (auscultare, to listen), a term in medicine, applied to the method employed by physicians for determining, by the sense of hearing, the condition of certain internal organs. The ancient physicians appear to have practised a kind of auscultation, by which they were able to detect the presence of air or fluids in the cavities of the chest and abdomen. Still no general application of this method of investigation was resorted to, or was

be examined some solid substance named a pleximeter
(stroke-measurer), upon which the percussion strokes are
made either with the fingers or with a small hammer tipped
with india-rubber. The pleximeter consists of a thin oval
piece of ivory; but one or more fingers of the left hand
applied flat upon the part answer equally well, and this is
the method which most physicians adopt. Percussion must
be regarded as a necessary part of auscultation, particu-
larly in relation to the examination of the chest; for
the physician who has made himself acquainted with the
normal condition of that part of the body in reference to
percussion is thus able to recognize by the ear alterations
of resonance produced by disease. But percussion alone,
however important in diagnosis, could manifestly convey
only limited and imperfect information, for it could never
indicate the nature or extent of functional disturbance, or
distinguish between different forms of disease, even in
those organs which it had proved to be in an abnormal
condition, while in other cases, and notably in many affec-
tions of the heart, it could afford no assistance whatever.
In 1819 the distinguished French physician, Laennec,
introduced the method of auscultation by means of the
stethoscope (ornos, the chest, and σKOTέw, to examine),
with which his name stands permanently associated. For
some time previously, physicians, more especially in the
hospitals of Paris, had been in the habit of applying the
ear over the region of the heart for the purpose of listening
to the sounds of that organ, and it was in the employment
of this method that Laennec conceived the idea that these
sounds might be better conveyed through the medium of
some solid body interposed between his ear and the '
patient's chest. He accordingly, by way of experiment,
rolled up a quire of paper into the form of a cylinder and
applied it in the manner just mentioned, when he found,
as he states, that he was able to perceive the action of the
heart more distinctly than he had ever been able to do by
the immediate application of his ear. He thence inferred
that not merely the heart's sounds, but also those of other
organs of the chest, might be brought within reach of the
ear by some such instrument, and he, therefore, had con-
structed the wooden cylinder, or stethoscope, which bears
his name. This consisted of a cylindrical piece of wood,
about 12 inches long, with a narrow perforation from end
to end, the extremity for applying to the chest having a
movable piece of conical form fitting into the cylinder,
which was withdrawn by the physician while listening to
the sounds of respiration, the complete instrument being
used for examining the sounds of the voice and those of
the heart. This instrument, though rendered portable by
being made to screw into two halves, was inconveniently
large and heavy, and was subsequently modified by Piorry
to the form now generally used of a thin narrow cylinder
of about 7 inches long, with an expansion at one end for
applying to the chest, and a more or less flattened surface
at the other for the ear of the listener. Having ascertained
by careful observation the sounds elicited on auscultation
of the healthy chest, Laennec studied the modifications of
these as produced by disease; and by comparing cases
with one another, and especially by investigating the state
of the affected parts after death, he was able, in his cele-
brated Traité de l'Auscultation médiate, to lay the founda-
tion for a rational system of diagnosis of the great classes
of pulmonary and heart complaints. It does not, how-
ever, appear to be the case, as Laennec supposed, that
mediate auscultation by the stethoscope is superior in an
acoustic point of view to immediate auscultation by the