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Overview

Jacques du Chevreul (1595-1649). Jacques du Chevruel was born in Coutances, France and died in Paris, France. Du Chevreul grew up in an educated household and was the son of a magistrate. In 1616, he received a Master of Arts for study humanities and philosophy at the University of Paris. Du Chevreul continued education at a higher level and received a bachelor of divinity for theology in 1619. He did not start teaching until 1620 where he remained associated with College Harcourt and University of Paris, up until two years before his death where he taught philosophy at the College Royal. Throughout his lifetime Jacques du Chevreul held various teaching and administrative positions including principal and rector. Little is known about his later life. Although he educated on subjects such as philosophy, logic, ethics, metaphysics, and physics, he published his two popular books over mathematics. Arithmetica (1622) and Sphaera (1623, 1640, and 1649) were both published in Paris, France. Sphaera, du Chevreul’s most popular book was about his view of the world and the universe. He used references from the Bible, Aristotle, and Plato to reject the Copernican model and instead created his own eccentric-epicycle geocentric model of the universe. Du Chevreul believed that the Sun was the center of the universe, but that major planets Venus and Mercury orbited around the sun. He theorized that there were wandering and fixed stars in the heavens and that there was a total of thirteen planets in his model. The heavens or the Universe some may say were in the order of the Moon, the Sun (Mercury and Venus orbited around the Sun), Jupiter surrounded by Medicean stars, Saturn, and above all these levels resigned God.

Jacques du Chevreul’s Depiction of the Universe

              The seventeenth century, a two-dimensional model drawn by du Chevreul was meant to be grasped as a solid demonstration however, the technology was not available to make a three-dimensional layout.  Jacques du Chevreul’s eccentric-epicycle geocentric template of the universe had elements like previous astronomers Ptolemy and Aristotle and modifications based on Galileo’s notes on lunar observation. The model, created in 1623 had, unlike other geocentric models of its time, sunspots surrounding and rotating the sun. Planets Mercury, Venus, Jupiter, and Saturn were also in rotation around the sun. Two planets Jupiter and Saturn, each had been given moons surrounding them with Jupiter having four and Saturn given two. The sunspots that du Chevreul incorporated into his depiction caused mixed interpretations between professions. Some mathematicians did not acknowledge such claims while schoolmen widely around France had thought the sunspots in du Chevreul’s depiction were small planets. The sunspots, however, could not be small planets, nor could they be spots according to Rene de Ceriziers who explained in his novel Le philosophe francais that if they were genuine spots on the sun, they would have been the same spots type of spots like the ones that affect the moon’s surface, which only arise from density and rarity of the planets parts. In the traditional view of that time no modifications he made to his earlier model needed to be significantly changed although Jacques did make changes to Mercury and Venus planet phases, the moons of Jupiter, sunspots, and the handles that surrounded the planet Saturn. Du Chevreul also accounted for the lunar spots/sunspots as celestial matter condensations and rarefactions. Through the modifications, Du Chevreul’s depiction of the universe maintained its spherical form and epicyclic-eccentric model.

Death

Jacques du Chevreul died in the year 1649 in Paris, France.

In this image, Jacques du Chevreul displays the earth, the moon, and the planets in a 3 o'clock Copernican arrangement. Opposite of the earth, but in the same orb, at 9 o'clock, du Chevreul adds the counter-earth required by original Pythagoreans.Reproduced from an original copy in History of Science Collections, University of Oklahoma Libraries.