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. 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.
Lanterns are first spoken of by Theopompus, a Greek poet, and Empedocles of Agrigentum. Lanterns were used by the ancients in augury. The only known representation of an ancient Egyptian lantern probably is not much different from those spoken of by John the Evangelist in John 18:3 from the New Testament, where the party of men who went out of Jerusalem to apprehend Jesus in the garden of Gethsemane is described as being provided “with lanterns and torches.” Lanterns in ancient China were made of silk, paper, or animal skin with frames made of bamboo or wood. One of the earliest descriptions of paper lanterns is found in records from Khotan, which describe a "mounting lantern" made of white paper.
The simplest technology used is the candle lantern. Candles give only a faint 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. A primitive form of candle lantern, made from white horn and wood and called a lanthorn, was first made in the time of the English king Alfred the Great (849–899).
Traditional and decorative lanterns
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.
Modern fueled lanterns
All fueled lanterns are somewhat hazardous owing 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 and can also use gasoline. These are being supplanted by a battery-powered fluorescent lamp and LED models, which are safer in the hands of young people and inside tents. Battery-operated lanterns are produced by many manufacturers including Coleman. Liquid fuel lanterns remain popular where the fuel is easily obtained and 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.
Modern electric lanterns
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 12-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.
Battery powered lanterns
Various battery types are used in portable light sources. They are more convenient and produce less heat than combustion lights. At least the lower energy density types tend to be safer than fuel use.
Large flashlights of six volts and more have often been called lanterns, even though they produce a directional beam.
The light emitting tubes of fluorescent lights are too big to easily be used to produce directional beam, but they are several times as efficient as incandescent filament bulbs and are useful for area illumination. They have partly replaced fuel lanterns for camping use, but are now being replaced by more compact and potentially even more efficient leds.
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 do and sometimes than fluorescent tubes of comparable brightness. Flashlights can be used as lanterns by diffuse (non-specular) reflection, or by removing the focusing components.
|Wikimedia Commons has media related to Lanterns.|
- Terry Pepper, Seeing the Light, Lighthouse of the western Great Lakes, Illumination.
- One or more of the preceding sentences incorporates text from a publication now in the public domain: "Lantern". Collier's New Encyclopedia. 1921.
- Needham (1985), p. 128.
- Ashden Awards case study on solar-powered lanterns in India
- Needham, Joseph (1985). Science and Civilisation in China: Paper and Printing. Cambridge University Press. ISBN 978-0-521-08690-5.