The former, fully renovated 16C bell tower of the church of Saint-Jacques-de-la-Boucherie, which was destroyed in 1797, was converted into a weather station (hence the statue of Blaise Pascal, who carried out his experiments on air pressure here in 1648) and then a factory for making hunting shot. Bought by the city at the request of the prefect Haussmann, it has been restored and modified on numerous occasions.