Free Brilliant by Jane Brox

arouse public interest. Many were curious, few were persuaded, and the thermolampe went no further.
    Gaslight found its first sustained application as light alone in British machine shops and cloth factories, where the limits of tallow and whale oil were keenly felt. This was especially true in the winter, when the working day continued long after darkness fell, and the wavering light cast by such illuminants made precision work difficult. To light their workrooms, some large factories needed hundreds, even thousands, of tallow candles or whale oil lamps. Each required individual attention—lighting, snuffing, replacing, filling, cleaning—never mind the stink, the irritating smoke, and the heat. In addition, any simple accident could mean disaster. Some owners of large factories so feared a conflagration that they kept their own fire engines on hand. Such light was costly, too. According to historian M. E. Falkus,
All factories ... used considerable quantities of oil and tallow in winter months. In 1806, one of the largest of Manchester's spinning factories, McConnel & Kennedy, burned candles for at least eight hours on the shortest days and averaged four hours lighting a day for six months of the year.... The annual cost of lighting McConnel & Kennedy's factory in 1806 was about £750. This firm burned an average 1,500 candles each night for 25 weeks in the year and consumed more than 15,000 lbs. of tallow.
    William Murdoch, chief engineer at Boulton and Watt—one of most prominent firms in England and builder of the first steam locomotive—experimented with coal gas at the same time Lebon was developing his thermolampe. Although others were also considering how to use coal gas, Murdoch achieved the first real success. His system differed from Lebon's only in its scale: he fitted retorts with pipes that carried distilled gas to huge reservoirs or storage tanks, called gasometers, and fitted the gasometers with outflow pipes, which could send gas, when needed, through mains and then smaller pipes to outlets.
    Murdoch lit his own cottage for his initial experiment, and then in 1802 he built a larger system for Boulton and Watt's forge in their Soho, Birmingham, factory. Its success led him to expand the system to include the workshops in Soho. In 1805 he began construction of a gaslight system for the Phillips & Lee cotton mill in Manchester, which he completed several years later:
It was estimated that more than 900 burners produced light equivalent to 2500 tallow candles burning on average for 2 hours on each working day. The factory contained eleven gasometers, six retorts, and more than two miles of pipes. Total expenditure on the plant was in excess of £5000, the cost of gas was about £600, allowing for depreciation of the equipment and the sale of the coke manufactured as a by-product.... The equivalent light produced by tallow candles would have cost an estimated £2000 a year.
    These very first gaslight systems probably didn't significantly improve the quality of light in the workrooms. Most observers of the time claimed that one gas burner gave a light three to six times brighter than a common oil lamp, but they had no accurate way of measuring the difference, only a comparison of shadows, which at the time was explained this way:
Suppose it were required to know how many candles, of a given size, were equal to a patent [Argand] lamp:—place the lamp at one end of the mantle-piece
[sic],
and the candles at the other; hold up the snuffer-tray, a book, or any other object of which the shadow can be received on a sheet of white paper against the opposite wall; the object must be held in a line with the middle of the mantelpiece: the lamp will produce one shadow and the candles another; when the shadows are equally dark the lights are equal; the darkest shadow will be produced by the strongest light.
    To its advantage, a gas flame could be larger than an oil lamp's because it wasn't