METIUS, JACOB

(b. Alkmaar, Netherlands; d. Alkmaar, June 1628)

mathematics, instrument making.

The father, Adriaen Anthonisz, was a cartographer and military engineer for the States of Holland, and between 1582 and 1601 he was burgomaster of Alkmaar several times. In an unpublished pamphlet Tegens de quadrature des circkels van Mr. Simon van Eycke (1584), he gave, according to his son Adriaen (1625), the value of 355/113 for what we now denote by │ stating that it differs from the true value by less than 1/100,000. He obtained it by averaging numerators and denominators of the values 377/120 and 333/106. (This value had already been obtained by Tsu Chung-chih in the fifth century.) Anthonisz built fortifications in the war against Spain, drew charts of cities and military works, and wrote on sundials and astronomical problems. In the receipt for his burial the name Metius, adopted by some of his sons, is mentioned, The origin of the name is uncertain: some derive it from Metz, others from the family name Schelven (schelf = rick = Latin meta), it may also simply be related to metiri (to measure). Anthonisz and his wife Suida Direksd. had one daughter and six sons, of whom two, Adriaen and Jacob, became widely known.

The second son, Adriaen, educated at the Latin school in Alkmaar, entered the recently founded University of Franeker in Frisia in 1589, and in 1594 continued his studies at the University of Leiden. Among his teachers in Leiden were the mathematicians Rudolf Snellius and Van Ceulen. Like his townsman Blaeu, Adriaen worked under Tycho Brahe at his observatory on the island of Hven; he then went to Rostock and Jena, where in 1595 he gave his first lectures. He returned to the Netherlands where he assisted his father in his military engineering until, in 1598, he was appointed professor extraordinarius at Franeker; in the same year he published his first book, Doctrina spherica.

Adriaen became professor ordinarius of mathematics, surveying, navigation, military engineering, and astronomy at Franeker in 1600, a position he held until his death. He bought mathematical and astro nomical instruments, observed sunspots, and showed familiarity with the telescope, of which his brother Jacob was a coinventor. He especially appreciated its use for measuring instruments. In his Geometria practica (Franeker, 1625) he described a triangulation of part of Frisia, made shortly after Rudolf Snellius’ son Willebrord had published his triangulation of the west Netherlands in Eratosthenes batavus (1617). Adriaen was a popular and efficient teacher who stressed the training of Frisian surveyors. His lectures were well attended by an international audience including, in 1629, Descartes. In 1625 Adriaen received an honorary doctorate in medicine from Franeker. He was married twice, first to Jetske Andreae, and then to Cecelia Vertest. He left no children. His motto was “Simpliciter et sine strepitu.”

Adriaen’s books cover all fields that he taught, and although they show little originality, they were widely used in his time. He followed Tycho Brahe’s theory of the solar system, but also showed respect for the Copernican system. While not accepting astrology, he did believe in alchemy, and spent money in the search for the transmutation of metals.

His brother Jacob was as shy as Adriaen was sociable. He became an instrument maker in Alkmaar, specializing in the grinding of lenses. He made several inventions but rarely showed them to others, even to his brother. He was one of the claimants to the invention of the telescope, and is mentioned as such by Descartes in his Dioptrique(1637). Jacob was indeed one of the first to bring a concave and a convex lens together in a tube, thus constructing a telescope. In 1608 he applied for a patent on such an instrument but unfortunately a similar request had been made a few weeks earlier by H. Lippershey of Middelburg. This disappointment may have intensified Jacob’s shyness. Adriaen, in several of his books after 1614, refers to his brother’s “perspicilla” (telescope). He expresses the hope that he would allow others to share in his discoveries, but Jacob remained secretive. Before his death he destroyed his instruments so that, as a contemporary said, “the perfection of his art has died and been buried with him.”

BIBLIOGRAPHY

I. Original Works. A satisfactory bibliography of Adriaen Metius’ works does not exist. Boeles lists seventeen titles, de Waard eighteen, and Bierens De Haan thirty-three, but some are reprints, trans., or collections. Boeles also lists a map of Frisia and a celestial globe from J. Janssonius’ cartographic workshop (1648). Some titles are Institutiones astronomiae et geographicae, found together with Geographische Onderwysinghe waer in ghehandeld wordt die Beschryvinghe ende Afmetinghe des Aertsche Globe (Franeker, 1614; Amsterdam, 1621); Arithmetica et geometrica nova (Franeker, 1625); Arithmeticae libri II et geometriae libri VI. Hic adiungitur trigono metriae planorum methodus succincta (Leiden, 1626); Geometria practica (Franeker, 1625), which states that “Parens P. M. illustrium D. D. Ordinum Confoederatarum Belgiae Provinciarum Geometra” found │ = 355/113 (pp. 88–89; “P. M.” is clearly “pia memoria”—Anthonisz died in 1620—and not P. Metius, as has occasionally been claimed to justify the term “ratio of Metius”); Maet-constigh Lineael … alsmede de Sterckten-Bouwinghe ofte Fortificatie (Franeker, 1626), which is a trans. of part of Arithmeticae libri II…, in which is described an early form of a calculating mechanism; Eeuwighe Handt-calendrier (Amsterdam, 1627; Rotterdam, 1628); Tafelen van de Declinatie des Sons (Franeker, 1627); Astronomische ende Geographische Onderwysinghe (Amsterdam, 1632); Manuale arithmeticae et geometriae practica (Franeker, 1633; 1646); Opera omnia astronomia (Amsterdam, 1632–1633), which contains the canon sinuum, tangentium et secantium ad radium 10,000,000.

II. Secondary Literature. On the father and sons see C. de Waard, “Anlhonis” and “Metius,: in Nieuw Nederlandsch Biographisch Woordenboek, I (Leiden, 1911), 155–158, 1325–1329 (in Dutch). In “Anihonisz,” he gives an account of Anthonisz’ MSS and published material. On Anthonisz’ value of │ see D. Bierens De Haan, “Adriaan Metius,” in Bouwstoffen voor de geschiedenis der wis- en natuurkundige wetenschappen in de Nederlanden, XII, repr. from Verslagen en Mededeelingen K. Akademic van Wetenschappen Amsterdam, Afdeling Natuurkunde, 2nd sen., 12 (1878), 1–35, The same author’s Bibliographie neerlandaise historique et seientifique sur les sciences mathématiques et physiques (Roms, 1883; Nieuwkoop, 1960) lists thirty-three works of Adriaen; this is a reprint of articles in Bullettino di bibliografia e di storia delle scienze maternaliche, 14 (1881), and 15 (1882), esp. 258–259. Also see his “Notice sur quelques quadrateurs du cercle dans les Pays-Bas,” ibid., 7 (1874), 99–104; and “Notice sur un pamphlet mathéma-Tique hollandais,” ibid., 11 (1878), 383–452. On Adriaen also see W. B. S. Boeles, Frieslands Hoogeschool, II (Leeuwarden, 1879), 70–75; and H. K. Schippers, “Fuotprinten fan in mannich Fryske stjerrekundigen,” in Beaken, 24 (1962), 77–104 (in Frisian). On Jacob, see C. de Waard, De uitvinding der verrekijkers (The Hague, 1906).

D. J. Struik