By the 1770's, the city of Boston had many lanterns lighting its streets. These lanterns were post lanterns and were manufactured by the English. The first fuel to be used in lanterns was whale oil. Thanks to Benjamin Franklin, the streets of Philadelphia were lit by 1751. He discovered that two wick tubes burning side by side a certain distance apart gave off more light than two separate burners. Different fluids were also experimented with for fuel. Camphene was one such fluid. It was a mixture of turpentine and alcohol and burned very bright. It was extremely dangerous, however, and therefore was replaced by other forms of liquid fuel. In 1807, London switched to gas for fueling lanterns. This was the start of the gas light era. The beautiful Westminster Bridge was lighted by gas in 1813, and the streets of Paris in 1818. There were several discoveries that increased the illumination of the gas light: pinching the end of the gas tube into a fan shape, surrounding the flame with a mantle of metallic oxide cloth, and mixing air with gas before the point at which is was lit. There are several different types of lanterns that have been used over the years, some of which are still being used today. Each type has its strengths and weaknesses, so check into each type to be sure you will have the amount of light you need.

Kerosene lanterns were commonly used for lighting rural homes without electricity, barns, and paths for nighttime visitors. Other uses for the kerosene lantern included: horse drawn carriages, railroad cars, ships, and early automobiles. However, the brighter carbide lamp was the preferred method of lighting for vehicles. Kerosene lanterns were often used for signaling and navigational marking for railroad, nautical, firefighting, and public works applications. Lanterns that were used for signaling often had interchangeable colored globes. Lanterns that were used for marking often had extra large fuel tanks that would permit continuous burning for up to 48 hours. Use of the kerosene lantern declined with the improvement of rural electricity, battery operated lamps, and the affordability of gas powered mantle lamps. Kerosene lanterns are still being manufactured today in China, some of which are being made with the original tooling from the early 1900's. In the United States, antique lanterns are a collector item, and are seldom lit. The few kerosene lanterns that are functional today are used for power outages or mood lighting. The Amish still regularly use kerosene lanterns.

References
www.wikipedia.org
www.periodlighting.com/history.htm

Touch lamps, however, most commonly use a fourth property of the human body to function--capacitance. Capacitance is the capability of an object to hold electrons. The lamp has a certain number of electrons when standing alone. To charge the circuit in such a lamp, a certain number of electrons are required. When you touch the lamp, your body adds to the capacity. It takes more electrons to fill the lamp and your body and the circuit detects that difference. Many touch-sensitive lamps have the ability to operate at three different levels of brightness. This is possible because the circuit changes the brightness of the lamp by changing the "duty cycle". This is the same concept as rapidly switching the light bulb on and off. The circuit uses zero percent, 33 percent, 66 percent, and 100 percent duty cycles to control the lamp's brightness.

My lamp will not touch on.
First, remember only metallic surfaces are touch sensitive. If this is not the problem, there are a few other things to consider. Make sure the touch lamp is not plugged into a wall outlet that is controlled by a dimmer. If this is the case, simply move the lamp to another outlet. Next, check that the outlet is controlled by a wall switch and check that the outlet switch is in the ON position and that the lamp is plugged in. If your lamp still isn't functioning, replace the light bulb with a new one-way bulb or test it in another lamp.

My light does not change settings when the lamp is touched.
If you have calluses on your fingers, they could be acting as an insulator. Try touching the lamp with the other hand or with a different part of the hand. If this doesn't work, find out if your carpets have been sprayed with an anti-static spray. These sprays are conductive and can ground out the signal. If this is the case, try again in another outlet.

My lamp changes setting with no one touching the lamp.
There are several reasons that this could be happening. First, there could be a cracked element in the bulb, which emits bursts of electronic energy and overwhelms the small touch sensor signal. If this is the case, replace the bulbs with any one-way bulbs. Second, it could be cause by power surges and strikes, which, over time, will cause your sensor to burn out. Third, if you are operating a ham radio, CB transmitter or some a garage door opener that emits high levels of energy, it could interfere with your lamp. These conditions are difficult to correct, but you can try moving out of the range of those energy bursts. Surge suppressors may also help.

My cordless telephone/intercom system causes my lamp to change settings.
Use a power line filter or surge suppressor.

The touch sensor on my lamp still isn't working.
If you are still experiencing problems with your touch lamp, you need to consult your owner's manual or contact the manufacturer.

References
http://home.howstuffworks.com/question42.htm
http://www.lifestylelighting.com/shop/assembly.shtml
http://www.1800doorbell.com/db800-touch-controls.htm

Soon after infrared radiation had been discovered, the German physicist Johann Wilhelm Ritter began to look for radiation at the opposite end of the spectrum, at the short wavelengths beyond violet. In 1801, he used silver chloride, a light-sensitive chemical, to show that there was a type of invisible light beyond violet, which he called chemical rays. At that time, many scientists, including Ritter, concluded that light was composed of three separate components: an oxidizing or calorific component, an illuminating component, and a reducing or hydrogenating component. The unity of the different parts of the spectrum was not understood until about 1842, with the work of Macedonio Melloni and others. During that time, UV radiation was also called actinic radiation.

The microorganism becomes unable to maintain metabolism or reproduce itself and subsequently perishes. All cells, when subjected to germicidal UV lights, undergo a similar process.

Tungsten-halogen lamps have bulbs made of quartz, not of ordinary glass. Tungsten-halogen lamps that are not filtered by an additional layer of ordinary glass are a common, useful, and possibly dangerous, source of UVB light.

UVC rays are the highest energy, most dangerous type of ultraviolet light. Little attention has been given to UVC rays in the past since they are filtered out by the atmosphere. However, their use in equipment such as pond sterilization units may pose an exposure risk, if the light is switched on outside of its enclosed pond sterilization unit.

UV lights can damage collagen fibers and thereby accelerate aging of the skin. UVA is the least harmful, but can contribute to the aging of skin, DNA damage and possibly skin cancer. It penetrates deeply and does not cause sunburn. Because it does not cause reddening of the skin it cannon be measured in the SPF testing. UVA light is also known as dark light and because of its longer wavelength, can penetrate most windows. It also penetrates deeper into the skin than UVB light and is thought to be a prime cause of wrinkles.

UVB light can cause skin cancer. The radiation excites DNA molecules in skin cells, causing covalent bonds to form between adjacent thymine bases, producing thymidine dimmers. Thymidine dimmers do not base pair normally, which can cause distortion of the DNA helix, stalled replication, gaps, and misincorporation. These can lead to mutations that can result in cancerous growths.

As a defense against UV radiation, depending on the skin types, the body tans when exposed to moderate levels of radiation by releasing the brown pigment melanin. This helps to block UV penetration and prevent damage to the vulnerable skin tissues deeper down. Suntan lotion that partly blocks UV is widely available and if often referred to as sun block or sunscreen. Most of these products contain an SPF rating that describes the amount of protection given. This protection applies only to UVB light.

High intensities of UVB light are hazardous to the eyes and exposure can cause welder's flash and may lead to cataracts, pterygium and pinguecula formation.

Protective eyewear is beneficial to those who are working with or those who might be exposed to the ultraviolet radiation, particularly short wave UV. Given that light may reach the eye from the sides, full coverage eye protection is usually warranted if there is an increased risk of exposure as in high altitude mountaineering. Mountaineers are exposed to higher than ordinary levels of UV radiation, because there is less atmospheric filtering and because of the reflections from snow and ice.

Ordinary eyeglasses give some protection and most plastic lenses give more protection than glass lenses. Some plastic lens materials, such as polycarbonate, block most UV. There are protective treatments available for eyeglass lenses that need it to give better protection. Most intraocular lenses help to protect the retina by absorbing UV radiation.

Ultraviolet radiation has other medical applications, in the treatment of skin conditions such as psoriasis and vitiligo. UVB and UVA radiation can be used, in conjunction with psoralens treatment.

To thwart counterfeiters, sensitive documents such as credit cards, driver's licenses, and passports, may also include a UV watermark that can only be seen when viewed under a UV emitting light. Passports issued by most countries usually contain UV sensitive inks and security threads. Visa stamps and stickers such as those issued by Ukraine contain large and detailed seals invisible to the naked eye but strongly visible under UV illumination. Passports issued by the United States have the UV sensitive threads on the last page of the passport along with the barcode.

Fluorescent lamps produce UV radiation by ionizing low pressure mercury vapor. A phosphorescent coating on the inside of the tubes absorbs the UV and coverts it to visible light.

The main mercury emission wavelength is in the UVC range. Unshielded exposure of the skin or eyes to mercury arc lamps that do not have a conversion phosphor is quite dangerous. The light from a mercury lamp is predominantly at discrete wavelengths. Other practical UV sources with more continuous emission spectra include xenon arc lamps, commonly used as sunlight simulators.

Ultraviolet fly traps are used for the elimination of various small flying insects. They are attracted to the UV light and are killed using an electrical shock or trapped once they come into contact with the device.

Ultraviolet lights are also used in analyzing minerals, gems, and in other detective work including authentication of various collectibles. Materials may look the same under visible light, but fluoresce to different degrees under ultraviolet light, or may fluoresce differently under short wave ultraviolet verses long wave ultraviolet. UV fluorescent dyes are used in many applications. Many substances have significant light absorption bands in the ultraviolet spectrophotometers are common in such laboratories.

A new application of UV lights is to detect corona discharge on electrical apparatus. Degradation of insulation of electrical apparatus or pollution causes corona, where a strong electric field ionizes the air and excites nitrogen molecules, causing the emission of ultraviolet radiation. The corona degrades the insulation level of the apparatus. Corona produces ozone and to a lesser extent nitrogen oxide which may subsequently react with water in the air to form nitrous acid and nitric acid vapor in the surrounding air.

Ultraviolet lights are used to sterilize workspaces and tools used in biology laboratories and medical facilities. UV lights can be an effective viricide and bactericide. Disinfections using UV lights was more commonly used in wastewater treatment applications but is finding increased usage in drinking water treatment. UV lights are used in several food processes to remove unwanted microorganisms. UV light can be used to pasteurize fruit juices by pumping the juice over a high intensity ultraviolet light source.

Resources:

WWW.MEMBERS.MISTY.COM
WWW.TOPBULB.COM