Carcel : A former French unit for measuring the intensity of light. The unit was defined as the intensity of a standard Carcel lamp, which burnt colza oil in a precisely defined way. One carcel equals about 9.74 candelas (See above)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}