The Carcel lamp was an efficient lighting device used in the nineteenth century for domestic purposes and in France as the standard measure for illumination. The lamp was invented by the French watchmaker

Bernard Guillaume Carcel Bernard ('' Bernhard'') is a French and West Germanic masculine given name. It is also a surname. The name is attested from at least the 9th century. West Germanic ''Bernhard'' is composed from the two elements ''bern'' "bear" and ''hard'' "brav ...

(1750–1818) to overcome the disadvantages of the Argand-type lamps then in use. The vegetable - mostly

colza Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historically, i ...

- oils then available were thick and would not travel far up a wick. The Argand lamps used a

gravity feed Gravity feed is the use of earth's gravity to move something (usually a liquid) from one place to another. It is a simple means of moving a liquid without the use of a pump. A common application is the supply of fuel to an internal combustion ...

which meant that the oil reservoir was located above the burner, casting a shadow and making the lamp top heavy. Carcel designed a lamp with the oil reservoir under the burner, in the body of the lamp. To keep the oil moving up to the burner, Carcel housed a clockwork mechanism in the lamp base that drove a small pump submerged in the oil tank. The winding key was located at the bottom of the lamp base. Another innovative feature was that fuel was pumped into the wick tubes at a greater volume than was necessary for burning so that it overflowed the top of the wicks, thus cooling the burner. The advantages Carcel claimed for his lamp in his 1800 patent in Paris were that the movement operated unattended, the oil could be used to the last drop, the lamp would stay lit for sixteen hours continuously without refilling, and it provided illumination for several persons at the same time with a single burner. They were complex devices however, and were expensive and prone to problems in the mechanism. They were most popular in wealthier European cities. Their unpopularity was partially due to the necessity of having to return them to the (mostly European) manufacturers for repair. In 1829 the simpler

Moderator lamp The moderator lamp is a type of 19th century oil lamp. It displaced the more complex Carcel lamp which used a clockwork pump. Its mechanism was simpler and required less maintenance or repair. The moderator lamp was invented in 1837 by Charles- ...

was invented, which dispensed with clockwork and used only a weighted piston to move the oil, and this eventually superseded them. The French physical standard Carcel lamp consisted of a cylindrical Argand burner, and gave the standard brightness when 42 grams of

colza oil Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historically, ...

were consumed per hour. The supply and draught were regulated by

clockwork Clockwork refers to the inner workings of either mechanical devices called clocks and watches (where it is also called the movement) or other mechanisms that work similarly, using a series of gears driven by a spring or weight. A clockwork mec ...

References

{{Lighthouses Oil lamp Lighthouse fixtures Photometry Units of luminous intensity Obsolete units of measurement

See also

References