STEVINUS, SIMON

(1548-1620)

Flemish physicist, engineer, and mathematician. His most notable achievement was the introduction of decimal notation into European mathematics. Little is known of his early life. A native of Bruges, he worked there and in Antwerp as a city financial clerk. Sometime between 1571 and 1577, he travelled in Poland, Prussia, and Norway. In 1581 Stevinus settled at Leiden and two years later matriculated in theuniversity. Later he entered the service of the Dutch government as an engineer and in 1604 be-came quartermaster-general of the army. He also tutored Maurice of Nassau, prince of Orange, in mathematics and wrote several text-books for his pupil. As a military engineer, he designed systems for flooding territory to guard against Spanish attacks. The government often consulted Stevinus on matters of defense and navigation, and he administered the personal domains of the prince of Orange. He also organized a school of engineers at Leiden.

By his time, Renaissance textual scholarship had recovered the ma-jor scientific works ofantiquity, and his own writings reflect the as-similation of this ancient knowledge while also demonstrating ability to push beyond what the ancient scientists had done. Stevinus wrote nearly all of his works in the Dutch vernacular, and his treatises cov-ered a vast range of scientific topics, both theoretical and applied. His books are clearly written and carefully organized, and they reflect the combination of theoretical science and practical application that was typical of the new Dutch republic. His first book,Tafelen van Interest(1585), reflected his commercial experience and made public the tables of interest that previously had been kept confidential by banking firms and insurance underwriters. His short bookletDe Thiende/The Deci-mal(1585) introduced the use of decimal fractions and explained their usefulness.That same year, he wrote a general treatise on arithmetic and algebra. Stevinus also wrote a mathematical work on the treatment ofperspectivein art, a treatise on the mathematical basis of tuning mu-sical instruments, and a series of other books making practical applica-tions of mathematical knowledge. HisDe Beghinselen der Weegconst/Principles of the Study of Solids(1586) is his major work on mechan-ics, dealing principally with statics.

Stevinus was the first Renaissance author to develop and continue the work of Archimedes, discussing the theory of the lever, rules for de-termining the center of gravity of an object, and, most important, the law of the inclined plane. His next work in that field,De Beghinselen des Waterwichts/Principles of Hydrostatics, is the first systematic treatise on hydrostatics since Archimedes. He also wrote a treatise on the design of windmills for operating drainage pumps, and he designed systems of sluices and locks to be used in the management of water. Stevinus' principal book on astronomy,De Hemelloop/The Course of the Heavens(1608), was an endorsement of the Copernican system an-tedating the full acceptance ofCopernicusbyGalileo. His works on astronomy were related to Dutch interest in navigation, and he pro-duced several specialized treatises, including one on the determination of longitude by use of the deviation of a magnetic needle from the as-tronomical meridian. Several of his publications were related to his ex-perience as a military engineer, including a treatise on fortification and a detailed discussion on laying out a military encampment.

Stevinus even wrote on political and social issues. HisHet burgherlick Leven/Civic Lifewas a guidebook for communities fac-ing civil disorder. He defended religion as socially necessary to de-velop moral character in children, and in the face of the religious wars and persecutions of his generation, he argued that an individual who dissents from the prevailing religion is obliged either to conform or to emigrate. Toward the end of his life, Stevinus collected and pub-lished many of his mathematical works inWisconstighe Ghedacht-enissen(two volumes, 1605-1608), a work that appeared almost si-multaneously in Latin and French translations.