Gabriel Mouton (1618 – 28 September 1694) was a
French abbot and
scientist. He was a doctor of theology from
Lyon, but was also interested in
mathematics and
astronomy. His 1670 book, the
Observationes diametrorum solis et lunae apparentium, proposed a natural standard of length based on the circumference of the Earth, and was decimally divided. It was influential in the adoption of the
metric system in 1799.