APHRODISIUS

, in Chronology, denotes the eleventh month in the Bythinian year, commencing on the 25th of July in ours.

APIAN or Appian (Peter), called in German Bienewitz, a celebrated astronomer and mathematician, was born at Leisnig or Leipsick in Misnia, 1495, and made professor of mathematics at Ingolstadt, in 1524, where he died in the year 1552, at 57 years of age.

Apian wrote treatises upon many of the mathematical sciences, and greatly improved them; more especially astronomy and astrology, which in that age were much the same thing; also geometry, geography, arithmetic, &c. He particularly enriched astronomy with many instruments, and observations of eclipses, comets, &c. His principal work was the Astronomicum Cæsareum, published in folio at Ingolstadt in 1540, and which contains a number of interesting observations, with the descriptions and divisions of instruments. In this work he predicts eclipses, and constructs the figures of them in plano. In the 2d part of the work, or the Meteoroscopium Planum, he gives the description of the most accurate astronomical quadrant, and its uses. To it are added observations of five different comets, viz, in the years 1531, 1532, 1533, 1538, and 1539; where he first shews that the tails of comets are always projected in a direction from the sun.

Apian also wrote a treatise on Cosmography, or Geographical Instruction, with various mathematical instruments. This work Vossius says he published in 1524, and that Gemma Frisius republished it in 1540. But Weidler says he wrote it only in 1530, and that Gemma Frisius published it at Antwerp in 1550 and 1584, with observations of many eclipses. The truth may be, that perhaps all these editions were published.

In 1533 he made, at Norimberg, a curious instrument, which from its sigure he called Folium Populi; which, by the sun's rays, shewed the hour in all parts of the earth, and even the unequal hours of the Jews.

In 1534 he published his Inscriptiones Orbis.

In 1540, his Instrumentum Sinuum, sive Primi Mobilis, with 100 problems.

Beside these, Apian was the author of many other works: among which may be mentioned the Ephemerides from the year 1534 to 1570: Books upon Shadows: Arithmetical Centilogues: Books upon Arithmetic, with the Rule of Coss (Algebra) demonstrated: Upon Gauging: Almanacs, with Astrological directions: A book upon Conjunctions: Ptolemy, with very correct figures, drawn in a quadrangular form: Ptolemy's works in Greek: Books of Eclipses: the works of Azoph, a very ancient astrologer: the works of Gebre: the Perspective of Vitello: of Critical Days, and of the Rainbow: a new Astronomical and Geometrical Radius, with various uses of Sines and Chords: Universal Astrolabe of Numbers: Maps of the World, and of particular countries: &c, &c.

Apian left a son, who many years afterwards taught mathematics at Ingolstadt, and at Tubinga. Tycho has preserved (Progymn. p. 643) his letter to the Landgrave of Hesse, in which he gives an opinion on the new star in Cassiopeia, of the year 1572. |

One of the comets observed by Apian, viz, that of 1532, had its elements nearly the same as of one observed 128 1/4 years after, viz, in 1661, by Hevelius and other Astronomers; from hence Dr. Halley judged that they were the same comet, and that therefore it might be expected to appear again in the beginning of the year 1789. But it was not found that it returned at this period, although the astronomers then looked anxiously for it; and it is doubtful whether the disappointment might be owing to its passing unobserved, or to any errors in the observations of Apian, or to its period being disturbed and greatly altered by the actions of the superior planets, &c.