A lantern is a portable lighting device or mounted light fixture used to illuminate broad areas. Lanterns may also be used for signaling, as 'torches', or as general light sources outdoors (such as camping). Low light level varieties are used for decoration. The term "lantern" is also used more generically to mean a 'light source' or the enclosure for a light source. Examples are glass pane enclosed street lights, or the housing for the top lamp and lens section of a lighthouse.[1]
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The simplest technology used is the candle lantern. Candles give only a weak light, and must be protected from wind to prevent flickering or complete extinguishment. A typical candle lantern is a metal box or cylinder with glass or mica side panels and an opening or ventilated cover on the top.
Decorative lanterns exist in a wide range of designs. Some hang from buildings, while others are placed on or just above the ground. Paper lanterns occur in societies around the world. Modern varieties often place an electric light in a decorative glass case.
The ancient Chinese sometimes captured fireflies in transparent or semi-transparent containers and used them as (short-term) lanterns. Raise the Red Lantern, a Chinese film, prominently features lanterns as a motif. Lanterns are used in many Chinese festivals. During the Ghost Festival, lotus shaped lanterns are set afloat in rivers and seas to symbolic guide the lost souls of forgotten ancestors to the afterlife. During the Lantern Festival, the displaying of many lanterns is still a common sight on the 15th day of the first lunar month throughout China. In Chinese festivities, the kongming lanterns can be seen floating high into the sky during festivities.
Use of fireflies in transparent containers was also a widespread practice in ancient India. But since these were short term solutions, the use of fire torches was more prevalent.
In the Eastern Orthodox Church lanterns are used in religious processions and liturgical entrances, usually coming before the processional cross.
Lanterns are also used to transport the Holy Fire from the Church of the Holy Sepulchre on Great Saturday during Holy Week.
All fueled lanterns are somewhat hazardous due to the danger of handling flammable and toxic fuel, danger of fire or burns from the high temperatures involved, and potential dangers from carbon monoxide poisoning if used in an enclosed environment.
Simple wick lanterns remain available. They are cheap and durable, but provide little light and are unsuitable for reading. They require periodic trimming of the wick and regular cleaning of soot from the inside of the glass chimney.
Mantle lanterns use a woven ceramic impregnated gas mantle to accept and re-radiate heat as visible light from a flame. The mantle does not burn (but the cloth matrix carrying the ceramic must be "burned out" with a match prior to its first use). When heated by the operating flame the mantle glows incandescently. Such lanterns are very bright, and can easily be used as reading lights. The heat may be provided by a gas, by kerosene, or by a pressurized liquid such as "white gas," which is essentially naphtha. For protection from the high temperatures produced and to stabilize the airflow, a cylindrical glass shield called the globe or chimney is placed around the mantle.
Manually pressurized lanterns using White gas (also marketed as Coleman fuel or "Camp Fuel") are manufactured by the Coleman Company in one and two mantle models. Some models are "dual fuel," which can also use gasoline. These are being supplanted by a battery-powered fluorescent lamp models by many manufacturers including Coleman. Liquid fuel lanterns remain popular where the fuel (see portable stove for a discussion on fuel) is easily obtained and is in common use.
Many portable mantle-type fuel lanterns now use fuel gases that become liquid when compressed, such as propane, either alone or combined with butane. Such lamps usually use a small disposable steel container to provide the fuel. The ability to refuel without liquid fuel handling increases safety and additional fuel supplies for such lamps have an indefinite shelf life if the containers are protected from moisture (which can cause corrosion of the container) and excess heat.
The leading manufacture of kerosene mantle lamps in the United States is the Aladdin Mantle Lamp Company, which has long produced an extensive line of utilitarian and decorative mantle lamps. A specialized cylindrical wick with a central airflow tube satisfies the high and uniform heating demands of the mantle.
Lanterns designed as permanently mounted electric lighting fixtures are used in interior, landscape, and civic lighting applications. Styles can evoke former eras, unify street furniture themes, or enhance aesthetic considerations. They are manufactured for use with various wired voltage supplies.
Some rechargeable fluorescent lanterns may be plugged in at all times and may be set up to illuminate upon a power failure, a useful feature in some applications. During extensive power failures (or for remote use), supplemental recharging may be provided from an automobile's twelve volt electrical system or from a modest solar powered charger. Solar-powered lanterns have become popular in developing countries where they provide a safer and cheaper alternative to kerosene lamps.[2]
Lanterns utilizing LEDs are becoming increasingly popular due to energy conservation, improvements in LED technology, and reduced production costs. Mounted lanterns can use LED lamps in the phase-out of incandescent light bulbs. LEDs have become brighter and more rugged. Battery-powered lanterns typically run longer (due to low current draw from the batteries) than incandescent bulbs or fluorescent tubes of comparable brightness.
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