6 Fact 1 Privileged with knowledge of the Latin language, Vlacq gets acquainted with Briggs' Arithmetica Logarithmica at the age of 25; he is not so sure about his own mathematical abilities, and consults some mathematicians or arithmeticians, including De Decker, on the potential usefulness of a fully completed "Great Table". His business instinct tells him that publishing a table for the European continent, in a living language like French or Dutch, with a full range of numbers of 1 to 100,000 - without a gap - and swiftly executed by suppressing some precision from Briggs' 14 decimals in the calculations, could be a worthwile and profitable investment. His conscience does not trouble him with possible plagiarism because, in his introduction to [3], Briggs has actually invited others to execute the calculations to resolve the gap in his Arithmetica Logarithmica. But Vlacq did not inform Briggs of his plan (which Briggs also had asked in his invitation); in the preface to his own publication [6], he describes in detail the above-mentioned motives for his approach, adding the altruistic remark this would ensure "sufficient copies to be available for this country, and also in an other language than Latin". Facts 2, 3 and 4 Vlacq's business sense also makes him legally contract partners for the project, and obtain copyright ("Privilegie") from the authorities ("Staten Generaal") to publish the "Great Table", for 10 years. What May Actually Have Happened: Fact and Fiction When we try to image the full story of Vlacq and De Decker, we might agree on the following scenario, which agrees with the facts above. The surprising aspect of fact 7 is that the one known copy of Tweede dee! van de Nieuwe Teikonst was discovered only in 1920, see [22]. This means that before 1920 all research on early tables was based on incomplete information, resulting today in a state of confusion: some people claim that De Decker was literally the first to print a complete logarithmic "Great Table" of 1 to 100,000, because of fact 7. Others, having used research results from before 1920, still believe Vlacq was the first. And then we have the majority who give credit for the "Great Table" to both Dutchmen equally, given the compelling argument: Without either of the two, the "Great Table" would not have materialised in Gouda. Vlacq provided the first initiative, his business sense, translation of Briggs' texts from Latin, some part of the calculations, the new trigonometrical tables and the successful academic 1628 edition [6] of the "Great Table" as part II of Briggs' work, while De Decker did the major part of the calculations and finalised the "Great Table" proper, although his commerce-oriented 1627 edition [5] did not reach the public.

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Schatkamer | 2005 | | pagina 8