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Friday, 1 April 2016

Lighting in the 19th, 20th and 21st centuries

This post is in two parts, the first is Chapter XV of the 1894 edition of "The Handbook of Household Management and Cookery" by W.B. Tegetmeier which gives a description of the options for lighting the home in late 19th century England.  The second has been compiled from family experiences in the 20th and 21st centuries.

Chapter XV - Lighting: Candles, Petroleum, Benzoline, and Gas Lamps, Their Management, etc.

99. Flame, which gives the light employed in our houses during the absence of the light of the sun, is always produced by the burning or combustion of inflammable gas.

When a candle is lit, the fat, wax, or other material of which it is formed, is melted, then drawn upwards into the flame by the attraction of the wick, it is there heated so strongly that it is converted into gas, which burns as fast as it is made, thus producing the flame.  In oil lamps the same happens, and in gas burners the gas burns as it escapes.

100. The gas which is burnt to give us artificial light, whether obtained from coals and supplied through pipes, or produced in the burning of a lamp or candle, consists chiefly of two substances, namely, hydrogen, which is always a gas, and carbon, which when not united with hydrogen or any other substance is usually a black solid, like charcoal or soot.

101. Both these substances burn in the flame, uniting with the oxygen of the air. The hydrogen in burning forms water, a large quantity of which passes off from every flame in the form of vapour or steam. Many gas lights in a close room make the air very damp, and the moisture they produce may often be seen settling on the cold glass of the windows, or even running down the walls. The carbon or charcoal when burnt forms carbonic acid, an invisible gas. When there are many gas lights in a badly ventilated room, or even one in a room that is not ventilated at all, the air becomes very unwholesome from the presence of carbonic acid gas.

102. If there is not enough air to enable both the carbon and the hydrogen to burn, the hydrogen burns first, and part of the carbon passes off in the form of smoke. By putting any cold pieces of metal, glass, or earthenware into a flame, the carbon is prevented from burning and settles on the metal or glass, covering it with black soot.

103. Candles, which were formerly very generally used, give out very little light and are the dearest mode of producing light.

Much may be learned of the nature of flame by watching attentively that of a common candle; at the bottom is a pale blue light which is caused by the fresh air rising against the flame and producing the perfect burning of both the carbon and the hydrogen; in the interior of the flame is a dark centre which consists of the unburnt inflammable gas rising from the wick; this cannot burn until it reaches the air outside. The outside of the flame is very bright it is there only the gas burns.

If a smalls slip of wood be held for a moment steadily across the centre of a flame, it will be seen that the part in the middle is not burnt, only that which was at the outside of the flame.

104. The oil used in lamps is of two distinct kinds. The fat greasy oils, such as seal or whale oil from animals, and olive or colza oil from vegetables.  obtain a good light from these fat oils it is necessary to make the flame hollow, and admit air into the interior, as is done in what is termed an Argand burner.

In order to cause a strong current of air through the flame of an Argand, a tall glass chimney is requisite.

105. The mineral oils, called paraffin or petroleum oils, are the cheapest oils in use They contain a very great amount of carbon or charcoal, and if they are burned without a chimney this escapes into the air in dark clouds of black smoke. These oils, therefore, require to be burned in a properly constructed lamp, so that sufficient air shall be sent against the flame to consume all the carbon.



The best paraffin lamps are those with a single flat wick, which is able to be turned to any required height above the wick tube A, by small toothed wheels turned by a handle, B. The large quantity of air required by the flame rises up through the cone or cap c, and is directed against the sides of the flame, producing a complete combustion of the carbon, and a very brilliant light.

Paraffin or petroleum oils were formerly sold containing much volatile inflammable spirit. At the present time no mineral lamp oil must be sold which is dangerous.

Petroleum lamps are perfectly free from danger if properly used. The oil-holder should be of glass, as if made of metal, it is apt to become heated. The lamps should always be filled before dark, and never after being lighted.

Any oil spilled on the outside should be carefully wiped off, or it will produce a disagreeable smell when the lamp is used. To light a petroleum lamp the glass chimney should be removed, then the wick turned above the slit in the cone, and when lighted instantly turned down again; the chimney should then be put on and the wick turned up so as to produce a large bright flame without smoke, but so as to produce the full If the flame, when the lamp burns without smell. flame is turned down low, there is no saving of oil, as a large quantity is sent off in vapour and produces a most disagreeable smell.

106. Sponge or spirit lamps are made for using the very inflammable spirit termed benzoline. They are filled with sponge or cotton wool which is moistened with benzoline, the wick-holder is then screwed on and the wick turned up level to the top; when lighted a small flame, rather greater than that of a candle, is produced. As the benzoline is very inflammable these lamps should never be trimmed after dark, or near a fire, as the vapour may take light. If trimmed in the day-time, and only enough spirit poured in to moisten the cotton wool, they are quite safe, and are the cheapest source of a small light. When used as night lights they should always be placed under a chimney as the vapour escapes and smells when they are turned down low.

Coal gas is unquestionably the cheapest source of light, but it's economy is not so great as is generally imagined ; the flame cannot always be brought where it is wanted, consequently a much greater amount of light is necessary than when movable lamps are employed.

For small rooms, the two-hole, or fish-tail burner is best, being cheap, simple, and capable of causing a very perfect combustion of the gas. With this burner the flame is spread out into a thin, flat sheet, by the two currents of gas striking against one another. In a fish-tail burner the gas should always be turned on so as to cause a full-sized flame without flickering, as otherwise the gas is not perfectly burnt. A large-sized burner should not be used where a smaller one will answer. The flame gives a much brighter and steadier light when placed horizontally with the flat sides turned up and down, than when burned upright in a glass globe, when the flame always flickers and is injurious to the eyes. An ordinary-sized fish-tail consumes from three to four cubic feet of gas per hour, and gives the light" of from six to nine candles.

Where a great amount of light is required a circular or Argand burner is more economical than the fish-tail.  In most burners the chimney is too high ; this causes too strong a current of air, and a great loss of light ensues. An Argand with a ring having fifteen holes, should not have a chimney more than seven inches high. Such a burner will consume about five cubic feet of gas in an hour, and give an amount of light equal to that of fifteen sperm candles.

In all cases where gas is used, the room should be ventilated, or the air will become very unhealthy from the great amount of carbonic acid and vapour of water produced.

Explosions sometimes occur when gas has escaped from a leaky pipe or a burner that has been left open, The explosion is generally caused by some person taking a lighted candle to discover the leakage, when the escaped gas takes fire instantaneously, and burns with a violent explosion. Whenever there is a strong smell of escaped gas, the main cock at the meter should be immediately turned, and the doors and windows opened to allow the gas to escape. No attempt should be made to search for the leak with a light, but notice should instantly be given to a gas-fitter.

The above describes the experiences of the old ladies of the family who were grateful for light that could be turned on or off with the flick of a switch, as girls, it has been their job clean grates, lamps and deal with soot, ashes, damp and lamp black.  Electric lighting started appearing in public places in the 1880s in the form of arc lamps which with electricity costing the equivalent of £5/kwh were expensive to run.  In the 19th century, electricity was a luxury product.

In our family homes started to be wired for electricity in the 1920s.  Typically, a room had a central pendant, maybe some wall lights in the living room and some movable lamps which plugged into wall sockets.  Incandescent bulbs were the main source of light for the better part of a century.  Bulbs got brighter, lasted longer and dropped in price but the main option was 40W, 60W or 100W bulbs which had a life of 1,000 hours and produced roughly 10 lumens/watt.  They had a secondary role as room heaters.  Some homes with water tanks in the attic had light suspended over the tank in the hope of preventing freezing and burst pipes in winter.  When electricity was first installed and the principal use was lighting, consumption was generally less than 1,000 kwh/year.  Wartime austerity reduced this to well below 500 kwh/year, but when peace returned there was a steady increase in consumption as new uses were fount for electricity.

Small fluorescent lamps known as Energy Efficient bulbs (a.k.a.CFLs) started appearing around 2005, initially they had an output of 30 - 50 lumens/watt and were expensive.  but it made economic sense to replace 100 watt incandescent lamps with 20 watt CFLs.  In 2009 European countries introduced legislation to phase out incandescent lamps.


In 2012, we started replacing CFLs with LEDs.  LED lighting has developed rapidly, some early offerings did not win the hearts and minds of consumers, but some of the current products produce around 80 - 100 lumens/watt and are a simple swap with CFLs and incandescent bulbs.


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