Jean-Joseph Tranchot

Jean-Joseph Tranchot (January 2, 1752 – April 30, 1815) was a French military cartographer. He is most well known for his topographical survey of the Rhineland under Napoleon, and his assistance in measuring the meridian arc of France with astronomer Pierre Méchain to determine to length of the meter.

Biography Tranchot was born on January 2, 1752, in Kœur-la-Petite, France. His parents were Remigius Tranchot, a carpenter, and Maria Maury.

Tranchot was first employed as a cartographer in 1774 in the triangulation of Corsica, which had been ordered by an edict from the French crown in 1770. Upon completion of this task, Tranchot studied astronomy with Pierre Méchain before he was given orders to triangulate and link his Corsica map with neighboring Sardinia and coastal Tuscany. This task was completed with use of a new invention, the repeating circle, from 1788 to 1791, and he was subsequently recognized by the Méchain and the French Academy of Sciences for his work. This final work lasted from 1801 until 1814. In this time, Tranchot completed 167 maps of the area, now known as the "Tranchot Maps". The project was finished in 1828 by Karl Freiherr von Müffling.

Tranchot died in 1815 from a stroke.

Tranchot Maps