The Collaborative International Dictionary
Carcel \Car"cel\, n. (Photom.) A light standard much used in France, being the light from a Carcel lamp of stated size and construction consuming 42 grams of colza oil per hour with a flame 40 millimeters in height. Its illuminating power is variously stated at from 8.9 to 9.6 British standard candles.
Wiktionary
n. (context historical English) A former unit to measure the intensity of light, approximately 9.74 candelas
Wikipedia
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 (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.
In modern terminology one carcel equals about 9.74 candelas.
Usage examples of "carcel".
The recruits rode with their animals close reined and they turned up past the courthouse and along the high walls of the carcel with the broken glass imbedded in the topmost course.
Instead, the guardhouses and the Carcel Modelo had been scraped for soldiers, most often bad ones, who could still be counted on to face down unarmed, unwarned people for a good price.
Archer and Janey trailed their long silk draperies up to the drawing-room, where, while the gentlemen smoked below stairs, they sat beside a Carcel lamp with an engraved globe, facing each other across a rosewood work-table with a green silk bag under it, and stitched at the two ends of a tapestry band of field-flowers destined to adorn an "occasional" chair in the drawing room of young Mrs.