Of the circumstances of his life very little is recorded; the exact day of his birth and the day and place of his death are alike uncertain. It is known that he left a widow with two children; and one or two hints scattered throughout his works inform us that he began life as a merchant's clerk in Antwerp, that he travelled in Poland, Denmark and other parts of northern Europe, and that he was intimate with Prince Maurice of Nassau, who asked his advice on many occasions, and made him a public officer'at first director of the so-called "waterstaet" (the government for water affairs), and afterwards quartermaster-general.

In Bruges there is a Simon Stevin Square which contains his statue by Eugen Simonis.

His claims to fame are varied. His contemporaries were most struck by his invention of a carriage with sails, a little model of which was preserved at Scheveningen till 1802. The carriage itself had been lost long before; but we know that about the year 1600 Stevin, with Prince Maurice of Orange and twenty-six others, made use of it on the seashore between Scheveningen and Petten, that it was propelled solely by the force of the wind, and that it acquired a speed which exceeded that of horses.

Another idea of Stevin, for which even Hugo Grotius gave him great credit, was his notion of a bygone age of wisdom. The goal to be aimed at is the bringing about of a second age of wisdom, in which mankind shall have recovered all its early knowledge. The fellow-countrymen of Stevin were proud that he wrote in their own dialect, which he thought fitted for a universal language, as no other abounded like Dutch in monosyllabic radical words.

He also gave the measure of the pressure on any given portion of the side of a vessel. He had the idea of explaining the tides by the attraction of the moon. In 1586 he demonstrates that two objects of different weight fall with the same speed.

Bookkeeping by double entry may have been known to Stevin as clerk at Antwerp either practically or through the medium of the works of Italian authors like Luca Pacioli and Gerolamo Cardano. He, however, was the first to recommend the use of impersonal accounts in the national household. He practised it for Prince Maurice, and recommended it to Sully, the French statesman.

His notation is rather unwieldy. The point separating the integers from the decimal fractions seems to be the invention of Bartholomaeus Pitiscus, in whose trigonometrical tables (1612) it occurs and it was accepted by John Napier in his logarithmic papers (1614 and 1619).

Stevin printed little circles round the exponents of the different powers of one-tenth. The fact that Stevin meant those encircled numerals to denote mere exponents is evident from his employing the very same sign for powers of algebraic quantities. He does not even avoid fractional exponents, and is ignorant only of negative exponents.

Stevin wrote on other scientific subjects—optics, geography, astronomy—and a number of his writings were translated into Latin by W. Snellius. There are two complete editions in French of his works, both printed at Leiden, one in 1608, the other in 1634.

Stevin thought Dutch to be an excellent language for scientific writing, and he translated a lot of the mathematical terms to Dutch. As a result, Dutch is the only of the Western European languages that has a lot of mathematical terms that do not stem from Latin.

His eye for the importance of having the scientific language be the same as the language of the craftsmen may show from the dedication of his book De Thiende ('The Disme'): 'Simon Stevin wishes the stargazers, surveyors, carpet measurers, body measurers in general, coin measurers and tradespeople good luck.'

Furtheron in the same pamphlet, he writes: "[this text] teaches us all calculations that are needed by the people without using fractions. One can reduce all operations to adding, subtracting, multiplying and dividing with integers."

The words he invented evolved: 'aftrekken' (*subtract*) and 'delen' (*divide*) stayed the same, but over time 'menigvuldigen' became 'vermenigvuldigen' (*multiply*, the added 'ver' has no meaning) and 'vergaderen' became 'optellen' (*add*).

The word 'zomenigmaal' (*quotient* lit. 'that many times') has become the perhaps less poetic 'quotiënt' in modern day Dutch.

- [1] contains an HTML version (including hyperlinks to explanations) of De Thiende and its translations into English, French and Swedish, and scans of these books
- [1] contains a lot more information about Simon Stevin
- [1] is the text of the Catholic Encyclopedia about Stevin. The author can hardly conceal his admiration, and for the rest the article is mostly a bibliography of Stevin's work.
- [1] is the Simon Stevin article of the huge collection of biographies of the St. Andrews University

*Edited version of an article from an old encyclopedia*