Jean Leurechon

Jean Leurechon (c. 1591 – 17 January 1670) was a French Jesuit priest, astronomer, and mathematician, known for inventing the pigeonhole principle and naming the thermometer.

Life Leurechon was born in Bar-le-Duc where his father, also named Jean Leurechon, was a physician to the Duke of Lorraine. He sent Leurechon to be educated at the Jesuit university in Pont-à-Mousson but, learning of Leurechon's desire to take holy orders and wishing him instead to become a physician,

Leurechon taught mathematics from 1614 to 1629 at Pont-à-Mousson, in 1619 Leurechon published two works on a comet that became visible in November and December of 1618. In 1622 he published the book Selectæ Propositiones in Tota Sparsim Mathematica Pulcherrimæ. It was republished in many later editions. The 1624 book also contained the first use of the word "thermometer", replacing an earlier word "thermoscope" for the same device.