In 1833, Antoine LeCoultre founded the little workshop which was to become the Manufacture Jaeger LeCoultre. Antoine was a self taught watchmaker and a brilliant inventor. He devoted his whole life to achieve total precision and reliability. His work made a lasting impression on the history of watchmaking.

In 1844 Antoine LeCoultre was the first person to measure a micron. Such was the perfection of his watchmaking components no tool could determine their level of inaccuracy. To push the boundaries even further he created the worlds most precise measuring instrument. The Millionometer served as the standard for more than half a century. It measured components to the nearest thousandth of a millimetre.