The operation of the grave of the dead began around 1680, but only took on its full 

extent from 1757. The drainage (water evacuation) was done using horses. In 1771, 

an atmospheric machine called "newcomen" was installed. This fire pump, built by 

Belgian mechanics, made it possible to overcome the floods and to relaunch the most 

important production in the city center before 1789. Its imposing Verdeau remains 

the clear proof of this intense slate activity.