Although he did not invent decimals (they had been used by the Arabs and the Chinese long before Stevin's time) he did introduce their use in European mathematics. His notation was to be taken up by Clavius and Napier. Stevin states that the universal introduction of decimal coinage, measures and weights would only be a matter of time.
Stevin's notion of a real number was accepted by essentially all later scientists. Particularly important was Stevin's acceptance of negative numbers but he did not accept the 'new' imaginary numbers and this was to hold back their acceptance.
Uses decimals to compute first tables of logarithms, based on ratios, not exponents.
At their meeting Napier suggested to Briggs the new tables should be constructed with base 10 and with log 1 = 0. Briggs wrote that Napier proposed (see for example ):-
Briggs's first work on logarithms Logarithmorum Chilias Prima was published in London in 1617. The recent death of Napier is referred to in the preface as is Briggs reason to publish that work, namely:-
The completed tables were printed at Gouda, in the Netherlands, in 1628 in an edition by Vlacq in which Vlacq had added the logarithms of the natural numbers from 20,000 to 90,000. The tables were also published in London in 1633 under the title of Trigonometria Britannica. The printing of the London edition took place after Briggs had died but he had asked his friend Henry Gellibrand to look after the project on his behalf. Gellibrand was professor of astronomy at Gresham College and was particularly interested in applications of logarithms to trigonometry. He therefore added a preface of his own on applications of logarithms to both plane trigonometry and to spherical trigonometry.
Creates an algebra for measuring and analyzing lengths... analytic geometry.
x, x2 , and x3 and higher powers of x can all represent (measure) lengths [as well as areas and volumes].
Newton1643-1727/ Mercator 1620-1687:
Computation of Hyperbolic logarithms using decimals.
Newton and Leibniz 1646-1716:
use "limits and functions and numbers" with level of rigor typical of that period.