Etienne (1744-1832) et Paul-Etienne (1776-1827) LENOIR

Etienne Lenoir did not have much education. He trained as a locksmith and moved to Paris in 1772. His exceptional professional qualities quickly made him known and he received his first official orders in 1780. He was appointed engineer of the king in 1788, and developed many instruments, especially the repeater circle of Borda which will be used to measure the length of the meridian and determine the meter between 1792 and 1798. He is part of the Commission des Poids et Mesures and manufactures the first standard meters.
His son Paul-Etienne was part of the expedition of Bonaparte to Egypt, in charge of astronomical instruments; it is probable that he met Jomard there and then worked with his father. He was appointed engineer in 1809.
They will continue to manufacture many scientific instruments, in particular reflectors for the first lighthouses on the coasts of France.
The manufacture of slide rules began in 1820. But Paul-Etienne died in 1827, before his father, who will not take over the workshop (he is more than 80 years old). The rules made by the Lenoir workshop are therefore not many.