The kerosene lamp (widely known in Britain as a paraffin lamp) is any type of lighting device that uses kerosene (British "paraffin," as distinct from paraffin wax) as a fuel. There are two main types of kerosene lamp, which work in different ways, the "wick lamp" and the "pressure lamp."
The first description of a simple lamp using crude mineral oil was provided by al-Razi (Rhazes) in 9th century Baghdad, who referred to it as the "naffatah" in his Kitab al-Asrar (Book of Secrets). Modern versions of the kerosene lamp were later constructed by Polish inventor Ignacy Łukasiewicz in 1853 (in Lviv, Austrian Empire), and by Robert Edwin Dietz of the United States at about the same time; the question regarding the primacy of these two inventors' versions of the lamp remains unresolved.
A wick lamp is a simple type of kerosene lamp that works in a similar way to a candle. This type of lamp is also known as an "oil lamp" or, in the United Kingdom and Ireland, a "paraffin lamp." A wick lamp has a small fuel tank and a lamp burner attached to the top of it. There is also a wick, usually made of cotton. The lower part of the wick dips into the fuel tank and absorbs the kerosene. The top part of the wick extends out of the wick tube of the lamp burner, which typically includes a wick-adjustment mechanism. There are many variations in wick-lamp burner designs. The most common lamp burner is the hooded type, with four prongs to hold the glass chimney. The next most common are round-wick lamps, such as the Rayo-type, which have a flame spreader in the center of a round wick.
When the lamp is lit, the kerosene that the wick has absorbed burns and produces a clear, bright, yellow flame. As the kerosene burns, capillary action in the wick draws more kerosene up from the fuel tank.
Adjusting how much of the wick extends above the wick tube controls the flame. The wick tube surrounds the wick, and ensures that the correct amount of air reaches the lamp burner. Adjustment is usually done by means of a small knob operating a cric, which is a toothed, metal sprocket bearing against the wick. If the wick is too high and extends beyond the burner hood at the top of the wick tube, the lamp will produce smoke and soot (unburned carbon).
A glass chimney usually protects the flame. The glass chimney acts to prevent the flame from being blown out and enhances the thermally induced draft. It needs a "throat" or slight constriction to create the proper draft for complete combustion of the fuel; the draft carries more air (oxygen) past the flame, helping to produce a brighter, smokeless light than an open flame would produce. Wick lamps can also be quite odorous if the kerosene is old or if the wicks and burners are not thoroughly clean. A smoking, odorous lamp and blackened glass chimney are most often caused by improper adjustment of the burner or poor fuel.
Barn lamps (or lanterns) have several design variations. The earliest lanterns used the dead-flame design, where the flame was fed fresh air from beneath and warm air was expelled above. Because this design does not feed air directly, this type of lamp produces only a dim yellow light and is not much brighter than a candle. Most Aladdin-style lamps are dead-flame, but some use mantles to increase the light output. The following section contains details of these mantle lamps.
Tubular lamps were invented in the latter part of the 19th century when, in the late 1860s, Dietz Lantern designed the "hot blast" lantern, which recirculated a mix of fresh and warm air back to the flame through side tubes, thus improving oil-burning efficiency. By 1880, the "cold blast" lantern was designed, using a similar circulation system, but with only fresh air, to increase the brightness of the flame. Cold-blast lanterns are the brightest and most efficient of all wick-lamp designs.
Except for decorative purposes, emergency lighting, or in remote areas without electricity, kerosene lamps are rarely used today in countries with a developed national grid for electricity and natural gas, but were popular before electrical lighting became widespread. In other countries, kerosene is popular for space heating, lighting, and cooking stove fuel due to the relatively cheap cost of the fuel, appliances, and infrastructure.
A variation on the wick lamp is the mantle lamp, which has a circular wick that burns below a conical mantle containing thorium or other actinide or rare-earth salts that incandesce (glow brightly) when heated in a flame. Though it has a mantle, like pressure lamps and lanterns, it is not a pressure lamp.
As mantle lamps are considerably brighter than wick lamps, and produce a whiter light, a lamp shade is often desirable. They also consume fuel at a greater rate than simple wick lamps and produce commensurately large amounts of heat. A few operating mantle lamps can serve to heat a small building in cold weather.
Mantle lamps, because of the higher temperature at which they operate, do not produce much of an odor except when they are first ignited or extinguished. Like wick lamps, they can be adjusted for brightness, and can also be adjusted too high, which will cause the lamp chimney and the mantle to soot up.
If a too-high adjusted lamp is caught promptly, it can simply be adjusted down and the small amount of soot on the mantle will soon be burned off. If it is not caught soon enough, a "runaway-lamp" condition can result.
A runaway-lamp condition, with flames coming out of the top of the chimney, can be dangerous and difficult to extinguish. It can also crack the relatively expensive (and fragile) glass chimney, irreversibly soot up the mantle, and release large amounts of soot into the room. The best way to extinguish a runaway lamp is by covering the top with a non-flammable object, such as an empty steel can.
Once the runaway lamp has been extinguished and allowed to cool, the chimney can be cleaned with soap and water. A badly sooted up chimney may require the use of lye or oven cleaner. The mantle, if still intact, can often be salvaged by removing it from the burner and heating it in the flame of a blow torch, propane torch, or a gas stove burner. This can be a difficult procedure and may result in breaking the mantle. As mantles are expensive, it is worth the effort to try, however.
Mantle lamps are still made by the Aladdin Mantle Lamp Company in the United States.
Pressure lamps are far more sophisticated than wick lamps and produce a much brighter light, although they can be quite complicated and fiddly to use. This type of lamp is commonly known in the UK as a "Tilley lamp", after a manufacturer of the same name, and in North America as a "Coleman lantern" for similar reasons.
A pressure lamp has a fuel tank at the bottom with a small pump to pressurise the kerosene. There is a narrow gap up to the top of the lamp, called a flue, and at the top of the lamp there is a burner (gas outlet). Directly underneath the burner is the mantle, a fabric bag coated with chemicals that incandesce when heated by the gas flame.
The burner lamp is known for its brightness. It is so bright because of the amount of pressure that is placed onto the wick. This pressure allows a steady flow of fuel and a constant light.
If the mantle is damaged, heat may become focused and damage the glass surround (windscreen). After the first burning of a new mantle, the size of the mantle will reduce significantly, and the mantle will become more fragile.
This type of lamp is popular amongst campers and others who engage in outdoor activities. Gasoline-burning lamps have also been produced; these do not require any primer liquid. However, both have lost popularity in recent years to portable lamps that burn butane or propane gas, as well as electrical fluorescent lamps, as these are easier to use, though more expensive to run.
There are also portable kerosene stoves, which work in much the same way as pressure lamps.
Strong odors can be caused by the design of the lamp burner and chimney. Generally, larger lamp burners emit less odor than very small burners. Stale fuel, gummy burners, and clogged, dirty wicks are the main causes of strong odors. If a kerosene lamp is not used regularly, it should be emptied of kerosene, and the font (fuel tank), wick, and burner should be cleaned before storage.
The wick of a wick lamp may need to be trimmed periodically. The shape in which a flat wick is cut affects the shape of the flame it produces.
Pure paraffin (wax) oil (aka Ultra-Pure, Nowell's, etc.,) is marketed as "smokeless and odorless" lamp oil, but is improperly labeled in the United States for use in wick lamps and lanterns. In fact, it will not burn properly in lamps or lanterns with 5/8" or larger wick, and will create smoke and odor. Paraffin oil has a flash point in excess of 200°F, and will only burn half as bright as standard lamp oil or kerosene, and will sputter in lamps with deep founts, or that have 7/8" or larger wicks. It is suitable for use in candle lamps, similar to those used in restaurants. Paraffin oil is not recommended for use in antique lamps or lanterns as the higher ignition temperature may result in damage to the lamp. Pure paraffin oil can solidify in environments below room temperature, greatly limiting its suitability for outdoor or emergency use. Drug-store mineral oil is paraffin oil. (Note: "Paraffin" in the UK is "kerosene" in the United States, and should not be confused with solid paraffin wax or the Pure paraffin (wax) oil discussed above, both of which are sold in the US.)
Generic lamp oil is widely available in supermarkets and hardware stores. It is usually less expensive than pure paraffin oil, but costs considerably more than kerosene. Lamp oil burns cleaner and with less odor than kerosene.
K-1 kerosene(clear as water, or slightly yellow) is, in most countries, more readily available in bulk than lamp oil and is typically much less expensive. However, kerosene contains more impurities, such as sulfur and aromatic hydrocarbons, than lamp oil. Kerosene obtained from filling stations is more likely to be dyed red or contaminated with water than kerosene obtained in prepackaged containers.
The odors produced by burning kerosene in wick lamps can be quite objectionable indoors, unless the kerosene is fresh, the lamp, wick, and burner are kept scrupulously clean, and the lamp burner is adjusted properly. Kerosene should be stored away from sunlight in a cool, dark place, not longer than a year or so, as it will eventually deteriorate. Stale kerosene smells like furniture polish, and takes on a deep yellow color, or darker.
Red kerosene is slightly less expensive than K-1 kerosene, as no motor-fuel taxes are collected on it. It is generally available in bulk at filling stations in agricultural areas, for use in farm tractors or diesel generators.
Biodiesel is a clean-burning "green" alternative to kerosene. Biodiesel packaged for lamp burning is best purchased, to avoid biodiesel / diesel mixtures available at the majority of filling stations' biodiesel pumps.
Citronella oil is used for its insect-repellant properties, and can be burned in wick lamps or torches outdoors. This is meant for outdoor use only and generally has a yellow color. To improve wick life and make citronella oil burn cleaner, it can be mixed 50:50 with kerosene.
Sometimes dyes and fragrances are added to fuels, which can increase soot deposits on glass globes/chimneys, and reduce wick life. Some manufactures have even created special novelty formulations that will cause the flame to burn in different colors.
Kerosene lamps should only be operated with kerosene or lamp oil, but alternative fuels may be used in an emergency.
Whale oil burns incredibly bright, and was once the standard for use in illumination, but is rarely found, today, due to whaling regulations in most of the world.
Diesel fuel and home heating oil has a flash point greater than 200°F, and will not burn properly in conventional wick lamps/lanterns. Most diesel fuels have a fairly high sulfur content and contain fuel additives that produce toxic by-products if burned in a lamp. They also produce more soot than kerosene.
Jet A is safe to use, as it is essentially kerosene with a few harmless additives. It burns well in wick lamps.
One can even use lubricating oil, though not the sort found in aerosol cans. Because of the additives, use outdoors or in well ventilated areas.
Charcoal lighter fluid is usually suitable for wick lamps/lanterns; most brands are kerosene. Be certain, however, to use only the type intended for starting charcoal briquettes. The lighter fluid intended for cigarette lighters is naphtha, which is highly volatile and has a low flash point, making it dangerous to use in a wick lamp.