2. Blaise Pascal

Blaise Pascal [blεz paskal] (June 19, 1623, in Clermont-Ferrand, France – August 19, 1662, in Paris) was a French mathematician, physicist, and religious philosopher. He was a child prodigy who was educated by his father, a civil servant. Pascal's earliest work was in the natural and applied sciences where he made important contributions to the construction of mechanical calculators, the study of fluids, and clarified the concepts of pressure and vacuum by generalizing the work of Evangelista Torricelli. Pascal also wrote in defense of the scientific method.

In 1642, in an effort to ease his father's endless, exhausting calculations, and recalculations, of taxes owed and paid, Pascal, not yet nineteen, constructed a mechanical calculator capable of addition and subtraction, called Pascal's calculator or the Pascaline. The Musée des Arts et Métiers in Paris and the Zwinger museum in Dresden, Germany, exhibit two of his original mechanical calculators. Though these machines are early forerunners to computer engineering, the calculator failed to be a great commercial success. Because it was extraordinarily expensive the Pascaline became little more than a toy, and status symbol, for the very rich both in France and throughout Europe. However, Pascal continued to make improvements to his design through the next decade and built fifty machines in total.

In 1654, prompted by a friend interested in gambling problems, he corresponded with Fermat on the subject, and from that collaboration was born the mathematical theory of probabilities. The friend was the Chevalier de Méré, and the specific problem was that of two players who want to finish a game early and, given the current circumstances of the game, want to divide the stakes fairly, based on the chance each has of winning the game from that point. From this discussion, the notion of expected value was introduced. Pascal later (in the Pensées) used a probabilistic argument, Pascal's Wager, to justify belief in God and a virtuous life. The work done by Fermat and Pascal into the calculus of probabilities laid important groundwork for Leibniz' formulation of the infinitesimal calculus.

Pascal had poor health throughout his life and his death came just two months after his 39th birthday

3. John Napier

John Napier of Merchistoun (1550 – 4 April 1617) - also signed as Neper, Nepair - named Marvellous Merchiston, was a Scottish mathematician, physicist, astronomer/astrologer and 8th Laird of Merchistoun, son of Sir Archibald Napier of Merchiston. He is most remembered as the inventor of logarithms and Napier's bones, and for popularizing the use of the decimal point. Napier's birth place, Merchiston Tower, Edinburgh, Scotland, is now part of Edinburgh Napier University. After dying of gout, Napier was buried in St Cuthbert's Church, Edinburgh.

Advances in mathematics

Napier made further contributions. He improved Simon Stevin's decimal notation. Arab lattice multiplication, used by Fibonacci, was made more convenient by his introduction of Napier's bones, a multiplication tool using a set of numbered rods. He may have worked largely in isolation, but he had contact with Tycho Brahe who corresponded with his friend John Craig. Craig certainly announced the discovery of logarithms to Brahe in the 1590s (the name itself came later); there is a story from Anthony à Wood, perhaps not well substantiated, that Napier had a hint from Craig that Longomontanus, Brahe's follower, was working in a similar direction.

4. Joseph Marie Charles dit (called or nicknamed) Jacquard

Joseph Marie Charles Jacquard (7 July 1752 (Lyon, France) – 7 August 1834 (Oullins, France) played an important role in the development of the earliest programmable loom (the "Jacquard loom"), which in turn played an important role in the development of other programmable machines, such as computers.

By 1800, Joseph began to dabble in inventing: a treadle loom in 1800, a loom to weave fishing nets in 1803, and starting in 1804, the “Jacquard” loom, which would weave patterned silk automatically. However, none of his inventions operated well and thus were unsuccessful.

In 1801, Jacquard exhibited his invention at the industrial exhibition at Paris; and in 1803 he was summoned to Paris and attached to the Conservatoire des Arts et Metiers. A loom by Jacques de Vaucanson on display there suggested various improvements in his own, which he gradually perfected to its final state. Although his invention was fiercely opposed by the silk-weavers, who feared that its introduction, owing to the saving of labour, would deprive them of their livelihood, its advantages secured its general adoption, and by 1812 there were 11,000 Jacquard looms in use in France. The loom was declared public property in 1806, and Jacquard was rewarded with a pension and a royalty on each machine.

The potential of Jacquard’s loom was immediately recognized. On April 12, 1805, emperor Napoleon and empress Josephine visited Lyon, and during their tour, they viewed Jacquard’s new loom. On April 15, 1805, the emperor granted the patent for Jacquard’s loom to the city of Lyon. In return, Jacquard received a lifelong pension of 3,000 francs; furthermore, he received a royalty of 50 francs for each loom that was bought and used during the period from 1805 through 1811.

Jacquard died at Oullins (Rhône), 7 August 1834. Six years later a statue was erected to him in Lyon, on the site where his 1801 exhibit loom was destroyed.