Gabriel Mouton

Gabriel Mouton (* 1618 in Lyon ; † September 28, 1694 ibid) was a French astronomer and mathematician.

Mouton studied theology in Lyon and was a clergyman at the Church of Saint Paul in Lyon. In his spare time he studied astronomy and mathematics.

Mouton is known for proposing a system of measurement based on a decimal scale in a book from 1670. Similar suggestions came from John Wilkins in England (1668) and Gottfried Wilhelm Leibniz in Germany (1673).

Mouton was referring to the measurement of the circumference of the earth by Giovanni Battista Riccioli in Bologna . The starting point was the arc minute of the meridian (1 milliare ). A thousandth (virga) of this corresponded to around 2 m as far as we know at the time and was close to the Toise unit of length (around 1.96 m), which was often used at the time . For the actual measurement, he suggested a pendulum. The period of a pendulum depends only on the length of the pendulum in one place on earth and a pendulum length of one tenth virga (the virgula , around 20 cm) corresponds to 3959.2 changes of direction in half an hour. His suggestions were received positively at the time ( Christian Huygens , Jean Picard , support from the Royal Society ) and played a role in the preparation of the decimal system of units implemented at the end of the 18th century.

His main work also deals with methods of interpolation . He also made tables of trigonometric functions and built a very accurate astronomical pendulum himself. As an astronomer, he measured the apparent diameter of the sun.

Fonts

• Observationes diametrorum solis et lunae apparentium, 1670

literature

• P. Speziali, Article Gabriel Mouton in Dictionary of Scientific Biography

Web links

• John J. O'Connor, Edmund F. Robertson :  Gabriel Mouton. In: MacTutor History of Mathematics archive .