Carcel lamp

The standard of light in France for many years was the Carcel lamp burning 42 grams of colza oil per hour and conforming to certain dimensions.

Carcel introduced the clockwork pump for supplying a regular amount of oil to the Argand Burner, in 1802. In this lamp, which should give 9.5 candles, the balance arrangement is to facilitate control of the rate of burning. Even so irregularities in the light given restricted the adoption of these lamps as an International photometric standard, the Hefner-Alteneck amyl-acetate lamp being preferred. In 1903, electrical standards were adopted.