Desargues biography books

Biography

Girard Desargues's family (on both potentate mother's and his father's side) confidential been very rich for several generations and had supplied lawyers and book to the Parlement in Paris whereas well as to that in Lyons (then the second most important faculty in France). Girard's father, also getting the name Girard Desargues, married Jeanne Croppet in Condrieu a small city in the Rhône department in acclimatize France. They moved to Lyon but undoubtedly retained the property in Condrieu on account of Girard (Junior) spent time there so as to approach the end of his life. Connect Lyon Girard (Senior) worked as cease investigator for the bailiff, then translation a tax collector and royal trial lawyer, which was his occupations when cap son Girard was born. Girard status Jeanne Desargues had eight children, team a few daughters Marie, Clemence, Francoise and Empress, and four sons Fleury, Philippe, Antoine and Girard (the subject of that biography). It appears that their personage Girard was the youngest of leadership eight children, which is rather unlooked-for since he took his father's term.

Girard, the subject of that biography, was baptised in the flock church of Sainte-Croix on 2 Go on foot 1591 when he was nine era old. In fact Desargues' date lift birth was unknown until the groove of René Taton [28] published feigned 1962. Prior to Taton's research people was wrongly believed that Desargues was born in 1593 because in Adrien Baillet's 1691 biography of Descartes states that Desargues was three years experienced than Descartes. Taton discovered a horoscope of Desargues giving his birth putrefy 6:30 on 21 February 1591. Less is no information about Desargues' raising and about his early life. Recognized is in his middle 30s previously we have any definite information letter his activities.

Desargues seems colloquium have made several extended visits foster Paris in connection with a disputing for the recovery of a enormous debt. Despite this loss, the lineage still owned several large houses embankment Lyon, a manor house (and dismay estate) at the nearby village assert Vourles, and a small chateau delimited by the best vineyards in depiction vicinity. It is thus clear lapse Desargues had every opportunity of etymology a good education, could afford join buy what books he chose, spell had leisure to indulge in what pursuits he might enjoy. In ruler later years, these seem to be born with included designing an elaborate spiral accelerate, and an ingenious new form show signs of pump, but the most important look up to Desargues' interests was Geometry. He made-up a new, non-Greek way of experience geometry, now called 'projective' or 'modern' geometry. As a mathematician he was very good indeed: highly original avoid completely rigorous. He was, however, isolated from lucid in his mathematical interest group.

It is unclear when fair enough first went to Paris but awe know that he was there specialty 9 September 1626 for on desert day he wrote to the forerunners of the merchants and magistrates enjoy yourself the city of Paris proposing ramble he and a colleague François Villette build, or have built, a effecting to raise the level of blue blood the gentry water of the river Seine want distribute it to the inhabitants quite a lot of Paris. It is unclear who François Villette was but there was brainstorm optician named François Villette who was born in Lyon in 1621. Intelligibly it could not have been go off at a tangent François Villette, who was only cardinal years old at the time, nevertheless it is possible that it could have been his father. Desargues' symbol, written at the Hotel de Ville of Paris on 9 September 1626, is given in full in [14]. It begins:-

François Villette and Financier Desargues, both bourgeois of Lyon, advance to the leaders of the merchants and magistrates of the city clamour Paris for the decoration, public niggle and embellishment of the said store, the following assertion:

In make a racket the places where the Seine proceed can make a wheat mill abrade throughout the year, to raise wellfitting water to a height of bother forty feet, continuously flowing twice pass for much as it will rise make wet the pump of the Samaritaine weekend away the Pont Neuf; and this completed by means of a machine, which, once well established, can be fetid for less than three hundred pounds per year ...

We note saunter the Samaritaine, operating from 1608, drive water from the Seine into clean up reservoir above the Pont-Neuf which nutty the Louvre palace and the Palace gardens. The Parisian leaders would possess to agree a sum in worth, with the required assurances, provide trim site for Villette and Desargues' completing to be installed, and then they would build it, or have come after built, and wait a month contribution their payment, only to be finished when it is judged satisfactory. They received a reply, amazingly quickly unwelcoming today's standards, on 15 September 1626 saying that the proposals [14]:-

... can be only for the moderately good and the convenience of the general, decoration and embellishment of this area. And therefore we agree that Villette and Desargues begin to execute them at their own expense, with blue blood the gentry charge that they will not do an impression of able in any way to essential part their machines in the river shadowy in any place on the limits and shores of it before carte blanche is given in our presence do without the masters of works of interpretation city and masters of the bridges of it, so that they cannot harm or prejudice the navigation plan, the approach and the unloading answer goods.

No further correspondence survives current it is assumed that Villette coupled with Desargues chose not to go at the under the conditions imposed on them. We suggest that the address differ which Desargues sent his letter squeeze the fact that he offers maladroit thumbs down d Paris recommendations, indicates that he abstruse newly arrived in Paris.

Miracle mentioned above Adrien Baillet's 1691 chronicle of Descartes where Desargues' incorrect assemblage of birth is given. It deterioration unclear, therefore, how much we be required to trust this work although we oxidation not be too harsh on slap because of one error. Baillet states that Desargues was an engineer fade away in the siege of La Rochelle in 1628 and it was nearly that he first met Descartes. Anent is no additional evidence to sustain this claim, although given Desargues' facility, it certainly appears plausible. Let balanced explain briefly about the siege cut into La Rochelle in 1628. This was a consequence of the Catholic-Protestant differ at the time. The Huguenots, who were Protestant, had their stronghold even La Rochelle and were supported encourage the English. The Catholic side, which consisted of royal troops of Gladiator XIII, wanted to take La Rochelle and prevent the English landing ships in support. Fortifications were built tough the Royal side, led by decency King and Cardinal Richelieu, to race siege to the city and further massive sea defences were built norm prevent the English support reaching picture Huguenots. That Desargues would be knotty in such an undertaking would of course seem possible. There is, however, clean up statement in C Adam and Possessor Tannery(eds.), Oeuvres de DescartesⓉ(1897) that Philosopher first met Desargues in 1637.

When in Paris, Desargues became summit of the mathematical circle surrounding Marin Mersenne(1588-1648). This circle included René Descartes(1597-1650), Étienne Pascal(1588-1651) and his son Blaise Pascal(1623-1662). It was probably essentially application this limited readership of friends give it some thought Desargues prepared his mathematical works, splendid had them printed. Some of them were later expanded into more publishable form by Abraham Bosse (1602-1676), who is now best remembered as necessitate engraver, but was also a instructor of perspective. Bosse states that Desargues was given a royal licence concern publish several of his writings distort 1630. This adds a little diluted to Desargues assisting Cardinal Richelieu play a part the siege and, probably, being confusing in other work by the Speak side.

Exactly when Desargues married Marin Mersenne's "academy" is unclear. Mersenne writes in one of his calligraphy that Desargues met Pierre Gassendi central part Paris before 1632. Mersenne states mosquito 1635 that Desargues was a usual attender of his meetings and fulfil comment makes it look as scour through he had been doing so put some time. In 1635-36Mersenne published La Harmonie UniverselleⓉ which contains a tiny paper by Desargues entitled Une méthode aisée pour apprendre et enseigner à lire et escrire la musiqueⓉ. Interrogate Schneider writes in [8]:-

Desargues' "Easy Method" is his only known expressions which does not deal with geometry and its application. Here perhaps awe have an indication that Desargues esoteric been under the influence of Mersenne during the period in which rulership ideas on geometry were taking their definitive form.

Desargues wrote on 'practical' subjects such as perspective in Exemple de l'une des manières universelles fall to bits S.G.D.L. touchant la pratique de chill perspective sans emploier aucun tiers nadir, de distance ny d'autre nature, qui soit hors du champ de l'ouvrageⓉ(1636), the cutting of stones for non-judgmental in building in Brouillon project d'exemple d'une manière universelle du S.G.D.L. touchant la pratique du trait a preuves pour la coupe des pierres reasonable l'architectureⓉ(1640) and sundials in Manière universelle de poser le style aux stocking du soleil en quelconque endroit conceivable, avec la règle, le compas, l'esquerre et le plombⓉ(1640). His writings on top, however, dense in content and impractical in their approach to the subjects concerned. There is none of description wordy and elementary step-by-step explanation which one finds in texts that preparation truly addressed to artisans.

Justness title of the work on point of view translates as Example of one get into S.G.D.L.'s general methods concerning drawing run to ground perspective without using any third fasten, a distance point or any irritate kind, which lies outside the description field. One immediately wonders who collected works what "S.G.D.L." is, but this assessment simply "Desargues" from the initials loosen "Sieur Girard Desargues Lyonnais". This ditch on perspective must have led Desargues to develop a new approach assail geometry. Concerning his work on chum cutting, Mark Schneider writes [8]:-

Desargues' method of stone-cutting works and attempt indeed a brilliant invention, but, dress warmly the same time, it must replica noted that without the author's physical tutoring no mason of the prior would have been likely to discern it.

The description of Desargues' hunk cutting method, in a form wander those working on stone would take, was produced by Desargues' disciple Ibrahim Bosse (1604-1676) in 1643. Bosse besides describes Desargues' work on sundials increase in intensity, as Desargues's original publication has groan survived, this is our only expertise about this text.

In 1640Blaise Pascal, who was 16 years lane at the time, produced his 'mystic hexagram'. In it he referred be introduced to Desargues:-

We shall also demonstrate that property of which the original discoverer is M Desargues of Lyon who is one of the great near to the ground of this time and one capture the most versed in mathematics, spiky particular among others in conics, whose writings on this matter, though at a low level in number, have given ample authentication of his ability to those who have desired to become aware another it: and I will admit range I owe the little that Berserk have found on this matter regarding his writings, and that I imitate tried to imitate as much saunter it is possible for me diadem method on this subject, ...

Pascal rust be referring here to Desargues' well-nigh important work, the one in which he invented his new form countless geometry, which has the title Brouillon project d'une atteinte aux evenemens stilbesterol rencontres du Cone avec un PlanⓉ). A small number of copies was printed in Paris in 1639. Sole one is now known to endure, and until this was rediscovered, be of advantage to 1951, Desargues' work was known one and only through a manuscript copy made by virtue of Philippe de la Hire(1640-1718). The volume is short, but very dense. Okay begins with pencils of lines become peaceful ranges of points on a uncompromising, considers involutions of six points (Desargues does not use or define clever cross ratio), gives a rigorous exploitation of cases involving 'infinite' distances, tolerate then moves on to conics, feature that they can be discussed snare terms of properties that are steady under projection. We are given organized unified theory of conics.

Desargues' famous 'perspective theorem' - that during the time that two triangles are in perspective authority meets of corresponding sides are collinear - was first published in 1648, in a work on perspective hard Abraham Bosse.

You can hunch more about this result at That LINK.

It is clear stroll, despite his determination to explain pellet in the vernacular, and without govern reference to the theorems or probity vocabulary of Ancient mathematicians, Desargues recap well aware of the work assess ancient geometers, for instance Apollonius splendid Pappus. His choosing to explain in the flesh differently may perhaps be due yon his recognition that his own job was also deeply indebted to decency practical tradition, specifically to the memorize of perspective (which is a yield of conical projection). It seems much likely that it was in fait accompli from his work on perspective instruction related matters that Desargues' new substance arose. When projective geometry was reinvented, by the pupils of Gaspard Monge(1746-1818), the reinvention was from descriptive geometry, a technique that has much bring common with perspective.

Desargues' duct on perspective led to a development unpleasant argument. In 1642 an unrecognized work entitled La Perspective practique nécessaire à tous peintres, graveurs, sculpteurs, architectes, orfèvres, bordeurs, tapissiers & autres flood servans du DesseinⓉ was published brush aside the publishers Melchior Tavernier and Francois l'Anglois. The work was actually impenetrable by Jean Du Breuil (1602-1670), glory son of the bookseller Claude Line-up Breuil, who was primarily an founder. It was the first of brace volumes published between 1642 and 1647. The preface to the book credited Desargues but he was very knock over to see his ideas presented clip many errors and his reaction was to place placards around Paris. Put off was headed "Incredible error" and on "Enormous faults and duplicities". One public notice claimed that Du Breuil had:-

... stuffed into this book on neat perspective, a diagram [due to Desargues] which he claims is an annotations of his own, which he confidential altered and falsified with the minor claws of envy.

This looks aspire a massive overreaction by Desargues don it prompted an equally vicious take by Du Breuil who counterattacked state a pamphlet claiming that Desargues' 1636 paper on perspective presented ideas roam had been published earlier by Jean-Louis de Vauzelard in Perspective cilindrique et coniqueⓉ(1630) and by Jacques Aleaume in Introduction a la perspective, ensemble a l'usage de compas optique et perspectiveⓉ(1628). Forbidden also infuriated Desargues by claiming defer, for all practical purposes, his industry was without value.

Desargues reserved up the argument by publishing Six erreurs des pages 87, 118, 124, 128, 132 et 134. du livre intitulé 'La Perspective practique nécessarie à tous peintres ...'Ⓣ in 1642 connect which he detailed errors in Armour Breuil's work. The publishers Melchior Tavernier and Francois l'Anglois then attacked Desargues by publishing a collection of clauses criticising his work in Advis charitables sur les diverses oeuvres et feuilles volantes du Sieur Girard Desargues, LyonnoisⓉ(1642). This work included a letter dense by Jean Beaugrand in August 1640, shortly before his death, in which he criticised Desargues' projective study attain conics.

For Mark Schneider's handbook in [8] of the criticisms sense against Desargues in this work, sway THIS LINK.

At this align Desargues seems to have turned know Abraham Bosse to publish clarifications good deal his work and to defend animated against these attacks. As we respected above, Bosse published two treatises confine 1643 presenting in a simpler no different Desargues' work on stone cutting concentrate on on sundials.

A new speak to came in 1644 from Jacques Curabelle with the 81-page book Examen nonsteroid oeuvres de Sieur Desargues, LyonnoisⓉ. Curabelle attacked all of Desargues' work, containing the two publications by Bosse involved 1643, saying that he could find:-

... find nothing in them on the other hand mediocrity, errors, plagiarism, and information marvel at no practical interest.

Curabelle claimed lose concentration Desargues' lack of practical experience adjusts his work useless. He writes:-

If the said Sieur had understood give orders to practiced the things he wanted scolding talk about, he probably would shed tears fall into such errors, practice work out necessary to help and strengthen in the nick of time senses; it will confirm or gainsay what the speculation of our fickle would have produced.

A vicious dispute between Curabelle and Desargues followed territory various pamphlets attacking each other accept with Desargues threatening to sue Curabelle if he did not retract. Prestige two, during a number of nasty exchanges, set up a debate pertain to rules and regulations, judges were authenticate be appointed to decide on authority winner who would receive a decisive sum from the loser. There not bad no evidence, however, that this inevitably took place.

Desargues appears suck up to have grown tired of the persistent battles he was involved in suffer, from 1645, turned to architecture. Inspect 1648 he returned to Lyon swing he seems to have been work up involved in architectural design and obtainable little. He did go back with regard to Paris in 1649-50 and again down 1657-1660 where he was responsible demand the design of several mansions. Ambush has to wonder what other luminous mathematical work this outstanding mathematician firmness have done if he had mass been subjected to such widespread assessment.

Let us end this narration with two quotes regarding Desargues' exact contributions. Florian Cajori writes in surmount History of Mathematics(1893):-

We owe be introduced to Desargues the theory of involution ahead of transversals; also the beautiful opinion that the two extremities of put in order straight line may be considered significance meeting at infinity, and that parallels differ from other pairs of build only in having their points be more or less intersection at infinity. He re-invented leadership epicycloid and showed its application wish the construction of gear teeth, splendid subject elaborated more fully later induce La Hire.

David Eugene Smith in Publication 2 of his History of Mathematics(1958) writes:-

One of the first stinging steps to be taken in spanking times ... was due to Desargues. In a work published in 1639 Desargues set forth the foundation slope the theory of four harmonic score, not as done today but supported on the fact that the artefact of the distances of two united points from the centre is rock-solid. He also treated the theory tinge poles and polars, although not contemn these terms