Former French unit for measuring the intensity of light
The Carcel is a former French unit for measuring the
intensity of light. The unit was defined in 1860 as the intensity of a
Carcel lamp with standard burner and chimney dimensions, which burnt
colza oil[1] (obtained from the seed of the plant Brassica campestris) at a rate of 42 grams of colza oil per hour with a flame 40 millimeters in height.[2][3]
In modern terminology one carcel equals about 9.74
candelas.[1]