he became a fellow of the Royal Society, to the Transactions of which, from 1723 to 1736, he communicated various papers on optical and physical subjects, and of which he was elected a vice-president. His principal claim to distinction is that of having been one of the original inventors of that class of instruments for measuring angles, in which one object is viewed directly, and another by successive reflections from two plane mirrors; the mirrors are adjusted until the two objects seem to coincide, when the angle subtended between the objects is double of the angle between the planes of the mirrors, and is read upon a graduated are fixed to one of the mirrors by means of an index fixed to the other, each real degree on the arc being reckoned as two degrees. The first inventor of an instrument of this class was Hooke, about 1664 or 1665; but his instrument did not succeed in practice. Newton invented one which would have succeeded, had it been constructed, as is shown by its resemblance to those now in use. The date of this invention is said to have been about 1669. Newton, however, did not publish his invention during his lifetime, but communicated it to Halley in 1700; a description and drawing of the instrument were found among his papers after his death, and published in the Philosophical Transactions for 1742. Reflecting instruments, almost identical in principle, were invented independently by Hadley and Godfrey in 1730 (see Godfrey, Thomas), and communicated by both inventors to the Royal Society in 1731.—(Phil. Trans. 1731.) Hadley's instrument was at first called an "octant," from its limb, a graduated arc, being the eighth part of a circle, and afterwards a "quadrant," from its being capable of measuring any angle not exceeding a right angle. When afterwards enlarged, so as to be capable of measuring an angle of one hundred and twenty degrees, it was called a "sextant," the limb being one-sixth part of a circle; and such is the form in which it is now generally used, and the name by which it is known.—W. J. M. R.
HADLUB, Johann, a German poet or minnesinger of the thirteenth century and the commencement of the fourteenth. He lived at Zurich, and appears to have occupied a humble station. His poems relate to his passion for a lady of more elevated position, who appears to have rejected his overtures. Notwithstanding the defects of their style and language, they contain much to interest the lover of nature, and the student of the manners of his time.—B. H. C.
HADRIANUS. See Adrian.
HAEBERLEIN, Franz Dominikus, a German historian and political writer, born January 31, 1720; studied at Ulm and Göttingen, after which he became professor of history at Helmstädt in 1747; in 1751 professor of law, &c. He wrote a great variety of works, including a supplement to Maittaire of books printed before 1500; a sketch of the political history of the eighteenth century; a history of the Pragmatic Sanction; historical treatises relating to Genoa, Denmark, Germany, &c. He died in 1787.—B. H. C.
HAEBERLIN, Karl Friederich, son of the preceding, born at Helmstädt in 1756; studied at his native place, and at Wolfenbüttel. He was professor of law at Erlangen, where he collected the materials for his Repertory of German state and feudal law. In 1786 he became professor at Helmstädt, where he died in 1808. He was intrusted with several important offices; and besides his various works on law, wrote one on the suppression of German monastic institutions.—His son, Karl Ludwig, born at Erlangen in 1784, after spending some years in the public service, attained distinction as a novelist—B. H. C.
HAEDO, Diego de, a Spanish monk and historian, born in the sixteenth century, but of whose life not much is known. A relative of the same name was archbishop of Palermo, and Diego became his chaplain. At Palermo he became acquainted with christian captives ransomed from slavery in Barbary, and from their information, and a journey he himself appears to have made to Algiers, or Argel, as he terms it, he compiled a curious account called "Topographia e Historia general de Argel;" Valladolid, 1612. The work is rare, but important for the light it throws upon a portion of the history of Cervantes, and for other details. It is not known when Hædo died.—B. H. C.
HAEFTEN, Nicolaus van, Dutch painter and engraver, a native of Gorcum, flourished about the end of the seventeenth century: the date commonly assigned for his birth, 1690, is plainly an error, some of his plates, as Nagler observes, being dated 1695. He painted Dutch boors and portraits, and engraved a large number of prints from his own designs, using alike the etching-needle, burin, and mezzotint-scraper. His etchings are very numerous, but his mezzotints are most esteemed. Such titles as "Rustics Smoking," "Old Man at a Window," and "Quack-doctor with a Flask," sufficiently indicate his range of subjects.—J. T—e.
HAELWEG, Albert, designer and engraver, resided in Copenhagen about 1645-70. Some writers give this last as the year of his birth; but, as Nagler observes, it must be nearer that of his death, since Rumohr and Theile, who describe one hundred and thirty-three prints by him, have found none later than 1672. In 1647 he appears to have borne the title of engraver to the king. He engraved a large number of portraits of the sovereigns and eminent men of Denmark after C. van Mander and others, with a few portraits of distinguished Englishmen; also some mythological and scriptural subjects. His works are rare, and somewhat in request, but they are hard and crude in style.—J. T—e.
HAEN, Anton van, M.D., one of the most illustrious physicians of his day, was born at the Hague in 1704, took his degree at Leyden, and afterwards practised his profession in his native town for twenty years. He was a pupil of Boerhaave, by whom he was much esteemed; and his merits as a physician were well known to Van Swieten, who invited him to Vienna to assist him in the enterprise in which he was engaged by the Empress Maria Theresa, viz., of reforming the faculty of medicine in that capital. At first he was called to the chair of the practice of medicine, and at the death of Van Swieten succeeded to the post of first physician in Vienna. During a long and successful career he enjoyed the confidence of the empress and the court, and educated an immense number of pupils. He died at Vienna in 1776.—W. B—d.
* HAERING, Wilhelm, a German novelist, better known by the nom de plume of Wilibald Alexis, born in 1798 at Breslau, Silesia, was educated at Berlin. After serving one campaign with a jäger corps and studying law, he published, in 1820, "Die Treibjagd." In his following two works, "Walladmor" and "Schloss Avalon," he imitated the style of Walter Scott, and was more successful. This encouraged him to cultivate chiefly the historical novel, and he published a long series of works of this class. He also wrote a number of comedies. In 1828 he started the Berliner Conversationsblatt, united in 1830 with Der Freimüthige. He edited, with E. Hitzig, the well-known collection of Causes Celébres, published under the title Der Neue Pitaval. The whole of his works were published in 1845 under the title of "Gesammelte Novellen," to which have since been added "Neue Novellen."—F. M.
HAEVERNICK, Heinrich A. C., a German theologian and critic of the school of Tholuck, was successively professor in the theological school of Geneva and in the universities of Rostock and Königsberg, and died while still young in 1846. From the dedication of one of his works to Tholuck, as his "beloved teacher and friend," it appears that he had studied under that eminent professor at Halle; and that it was under his influence that he learned to regard the prevailing rationalism with repugnance, and to resolve to consecrate his life to the defence and exposition of revealed truth. His first work was a commentary on Daniel, published in 1832, just before he proceeded to Geneva to join his colleagues, Gaussen, D'Aubigné, and Steiger, to all of whom he dedicated the work. His "Handbuch der historisch-kritischen Einleitung in das alte Testament," is a valuable introduction to the Old Testament, and appeared at intervals between 1836 and 1844. It was left incomplete by the author, and was continued and finished by his friend, Professor Keil of Dorpat. It is written in the spirit of Hengstenberg's important works in the same department, and, in its latter portions especially, is highly esteemed by his learned countrymen. In 1843 appeared his "Commentary on Ezekiel," a copious and elaborate work. His "Vorlesungen über die Theologie des alten Testaments," is a posthumous work, brought out under the eye of his attached friend. Professor Dorner, and carefully edited by Dr. H. A. Hahn of Königsberg. It is highly valued by the students of biblical theology, and exhibits the ripest fruits of Haevernick's studies in the Old Testament.—P. L.
HAFIZ or HAFITZ, Mohammed-Schems-ed-din, one of the most celebrated of the Persian poets, who divides with Firdusi and Saadi the admiration of his countrymen. He was born
