By 1846, the Smalls lighthouse had been guiding ships around the hazardous west coast of Wales for 70 years. Perched on one of the 鈥淪malls鈥�, a cluster of low-lying lumps of rock 34 \ kilometres from St David鈥檚 Head, the lighthouse鈥檚 water supply was somewhat precarious. Weather permitting, a supply ship brought casks. But the keepers also collected rainwater from a dripstone and from the roof of the tower.
Shut up for months on end with only each other for company, 19th-century lighthouse keepers often took to drink. Alcoholism was rife-and suicide an all too frequent consequence. But the keepers at the Smalls had foresworn alcohol. Tea was their tipple and the taste of the water was important. So when they suspected their water was tainted, they complained loudly. That April, samples were speeding towards London, for analysis at Michael Faraday鈥檚 basement laboratory at the Royal Institution.
Why would so famous a scientist bother himself with such a routine bit of chemistry? Because Faraday was scientific adviser to Trinity House, the lighthouse authority for England and Wales. And despite the wild and windy trips to remote lighthouses, frequent bouts of seasickness and often tedious assignments, Faraday put as much effort into his lighthouse experiments as he did the more glamorous ones that had made him a celebrity.
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鈥淢Y DEAR Sir, The accompanying bottles of water have been sent up from the Smalls Light House, the keepers at which establishment have, praiseworthily, become Tea Totaller-they think it is in some way impregnated with Copper-it is very desirable to ascertain if their suspicion be well founded, and to Contradict their belief if it be not so . . . 鈥�
Aware that this was a piffling request to put to so great a man as Michael Faraday, the Secretary of Trinity House worded his letter carefully. To him this was a serious matter. Keeping lighthouse keepers off the grog was hard enough at the best of times, and if the water was unfit to drink they would have every excuse to turn to something stronger. Who better to test the water than Faraday? He had the best-equipped lab in Britain and as the most famous scientist in Europe his findings would certainly have authority. Not only that, but Faraday would share his enthusiasm for tea drinking. He was after all a member of the Sandemanian Church, a Christian sect that disapproved of excessive drinking.
As it happened, the Smalls men were right to worry. Although the water from the dripstone was 鈥渧ery good and sweet鈥�, water from the roof was so badly contaminated with copper chloride it was positively poisonous-the result of seaspray reacting with the metal sheathing of the lighthouse roof. All keepers were immediately warned not to use such water for 鈥渃ulinary purposes鈥�.
Faraday was appointed adviser to Trinity House in 1836, a job he held for almost 30 years. By the 1830s he had already made the greatest breakthroughs of his career- including the principle of the electric motor, the transformer and the dynamo, work that paved the way for the development of technologies based on electricity. The research he did for Trinity House was far less exciting. Over the years he experimented with different oils, looking for one that would burn brighter and more efficiently. He checked out new designs of lamps and made improvements to the optics.
Lighthouse keepers had a lot of problems with water. One constant bugbear was the amount of condensation that ran down the windows of the lanthorn, the room at the top of the tower that housed the oil lamps. Condensation reduced the intensity of the light beam and in cold weather the water froze, dimming the light still more. In 1841, Faraday headed off to St Catherine鈥檚 lighthouse on the Isle of Wight to investigate. The cause was clear enough: when whale oil burns, it generates vast amounts of water vapour. 鈥淭he composition of Spermaceti oil is nearly 78 Carbon, 12 Hydrogen, 10 Oxygen per unit and when such oil is burnt 100 parts by weight inevitably produce 108 parts of water or above its own weight, the increase being from an element supplied from the air,鈥� Faraday explained.
Once he had identified the problem, Faraday sat down and designed a chimney to carry away the moisture and keep the lanthorn windows clear. After a few alterations, Faraday鈥檚 chimneys proved so effective they were installed in other buildings too- including Buckingham Palace.
By the late 1840s, Faraday was asked to look into the potential for using electricity to illuminate lighthouses. Here was a chance to show what a fantastic thing electric power was-and enhance his reputation as the man who had made it possible. But Faraday didn鈥檛 believe in progress at any price. He was more concerned about the safety of sailors than a few more feathers in his cap.
The first proposal he was asked to assess was a scheme to electrify light buoys. He turned it down as unreliable. 鈥淎n uncertain indication is worse than none,鈥� he wrote in explanation. In 1854, he was asked to examine a scheme for lighthouses suggested by Joseph Watson. Watson鈥檚 arc lights were powered by huge batteries. The intensity of the light produced was 鈥渕ost beautiful鈥�, Faraday said. But there were many drawbacks-not least the noxious fumes from the batteries and the need to employ a team of highly trained men to keep the batteries working.
Nor, said Faraday, were lighthouses the right place to test an unproven technology. 鈥淚 think therefore the Electric light should be tried in its other applications that its conditions & liabilities may be eliminated, its construction perfected-and a school provided where a body of men may be taught how to use it with certainty; before it is introduced into lighthouses,鈥� he reported to Trinity House. Watson got the thumbs down.
A few years later, Frederick Holmes, a chemist and engineer from London, proposed a better scheme. His lamps were powered by an electromagnetic generator driven by steam. After rigorous testing and a few modifications, Faraday gave this technology the go-ahead. In December 1858, two of Holmes鈥檚 generators began operation at South Foreland on the coast of Kent.
For the next five years, despite his age and increasingly poor health, Faraday monitored the light, travelling to and from the lighthouse in all weathers. 鈥淭he light shone up and down the Channel, and across into France with a power surpassing that of any other fixed light within sight. The experiment has been a good one,鈥� he wrote.
Unfortunately, it wasn鈥檛 a cheap one. Trinity House had hardly begun to convert its lighthouses to electricity when it took fright at the expense. In 1880, 13 years after Faraday鈥檚 death, the generators were removed and the lamps again lit with oil or gas. By the turn of the century, electric lights may have been common in ordinary homes-but they weren鈥檛 turned on again in lighthouses until 1922.