William Snow Harris
William Snow Harris | |
---|---|
Born | Plymouth, Devon, England | 1 April 1791
Died | 22 January 1867 | (aged 75)
Occupation(s) | solicitor and physician |
Sir William Snow Harris (1 April 1791 – 22 January 1867) was a British physician and electrical researcher,[1] nicknamed Thunder-and-Lightning Harris,[2] and noted for his invention of a successful system of lightning conductors for ships. It took many years of campaigning, research and successful testing before the British Royal Navy changed to Harris's conductors from their previous less effective system. One of the successful test vessels was HMS Beagle which survived lightning strikes unharmed on her famous voyage with Charles Darwin.[3][4]
Life and work
Harris was born in
He went to the University of Edinburgh to study medicine and qualified as a physician, then returned to Plymouth and set up a medical practice. His interest in the emerging science of electricity led him to invent his improved lightning conductor for ships in 1820. In 1824 he married, and decided to abandon his profession of medicine to concentrate on his studies of electricity. His paper "On the Relative Powers of various Metallic Substances as Conductors of Electricity", read before the Royal Society in 1826, led to him being elected a fellow of the society in 1831. He read papers on the elementary laws of electricity to the Society in 1834, 1836 and 1839, and also sent accounts of his experiments and discoveries to the Royal Society of Edinburgh.[1] His experimental investigations into the force of high intensity electricity were published in the Philosophical Transactions of 1834. In 1835 Harris received the Royal Society's Copley Medal for his "Experimental Investigations of the Forces of Electricity of high Intensity".[2][5][6]
Harris was curator of apparatus in the museum of The Plymouth Institution (now
His work on lightning conductors for ships gained him a government annuity of £300 "in consideration of services in the cultivation of science", and to overcome continued objections to his proposals he published an 1843 work on Thunderstorms, as well as contributing papers to The Nautical Magazine on lightning damage. He was knighted in 1847 after the system had been adopted and shown successful, and was given a grant of £5,000. Though his continued research did not find new discoveries, his manuals of Electricity, Galvanism and Magnetism were published between 1848 and 1856 and went through several editions. When he died in Plymouth on 22 January 1867 he had a Treatise on Frictional Electricity in preparation, and it was published later that year.[1]
Lightning conductor for ships
The lightning rod invented by Benjamin Franklin in 1752 suggested a way of avoiding the common problem of lightning causing damage to the wooden sailing ships of the period. In Britain, the Royal Navy chose a protection system with a chain draped into the sea from the top of the mast as a lightning conductor. This system proved unsatisfactory: the chain was only supposed to be raised up the mast when lightning was anticipated, and lightning often struck unexpectedly. When the chain was raised it was a nuisance to seamen aloft in the rigging to deal with the square rigged sails, and even when it was raised, lightning strokes would sometimes damage the chain or the ship. There were also fears that the conductors would attract lightning to the ship, and prejudices against their use.[4] The French navy devised a modified system in which the chain was led down the permanent rigging to connect to the copper sheathing which was used to protect the hull below the waterline against damage from collisions and shipworms. In the early 19th century they replaced the chains by metal cables.[3]
Harris invented a new system in 1820, with lightning conductor plates fixed along spars and down the aft side of the mast, right down through the hull to connect to the copper sheathing of the hull. All the principal metallic masses in the ship were to be
Trials on HMS Beagle
One of the first vessels outfitted for the test was
Near the end of 1831, while the Beagle was still being fitted out at
The voyage took almost five years, and although the Beagle was frequently exposed to lightning and was thought to have been struck by lightning on at least two occasions, "when—at the instant of a vivid flash of lightning, accompanied by a crashing peal of thunder—a hissing sound was heard on the masts; and a strange, though very slightly tremulous, motion in the ship indicated that something unusual had happened", there was never the "slightest damage".[13] Darwin himself reported this effect, and his conviction that "but for the conductor, the results would have been serious."[3] FitzRoy reported that the copper plates stayed firmly in place, even in small spars, and strengthened the spars rather than weakening them. FitzRoy gave the lightning protection high praise:[13]
No objection which appears to me valid, has yet been raised against them; and were I allowed to choose between having masts so fitted and the contrary, I should not have the slightest hesitation in deciding on those with Mr. Harris's conductors.
Whether they might be farther improved, as to position and other details, is for their ingenious inventor to consider and determine. He has already devoted so many years of valuable time and attention to the very important subject of defending ships against the stroke of electricity; and has succeeded so well for the benefit of others—at great inconvenience and expense to himself—that it is earnestly to be hoped that the Government, on behalf of this great maritime country, will, at the least, indemnify him for time employed and private funds expended in a public service of so useful and necessary a character.— FitzRoy, 1839.[13]
Harris continued his extensive campaign to publicise the extent of the problem of lightning damage. He presented a report listing the damage caused to British naval vessels during the period from 1793 to 1838, including lightning causing 62 deaths and 114 injuries. Two study committees gave favourable recommendations for his system, but full implementation continued to be blocked by the opposition of the
Harris continued to record the effects of lightning on ships of the Royal Navy, and published details of this research. In 1853 a report in The Nautical Magazine proudly stated that between 1830 and 1846 none of the ships protected by Harris conductors had suffered casualties from lightning, and they had not been struck by lightning to nearly the extent that unprotected ships had been. Taking a comparable period, at least 45 unprotected ships had been terribly damaged by lightning. It reflected on the boldness of leading the conductors down through the ship past crowded areas and combustible materials, and the prejudices the scheme had to overcome. It noted that the measure was founded on sound principles of science, and had been backed by eminent scientists including Sir Humphry Davy. Recalling the earlier opposition to Harris's proposals, it concluded with "feelings of satisfaction approaching to exultation at the complete success which has crowned his exertions".[14]
Selected books
- Rudimentary Electricity, being a Concise Exposition of the General Principles of Electrical Science. Published by John Weale, 59 High Holborn, London in 1848.
References
- ^ a b c d e Chisholm, Hugh, ed. (1911). . Encyclopædia Britannica (11th ed.). Cambridge University Press.
- ^ a b c Barlow 1967, p. 49
- ^ ISBN 978-0-521-87811-1.
- ^ S2CID 46380992.
- ^ Simon Rogers (14 August 2009). "Hans Christian Ørsted: what does he have in common with Stephen Hawking? | News | guardian.co.uk". The Guardian. Retrieved 27 October 2009.
- doi:10.1038/136882a0.
- ^ "Historic People". Plymouth Athenaeum. Archived from the original on 6 November 2014. Retrieved 7 November 2014.
- ^ a b FitzRoy 1839, pp. 18–19
- ^ FitzRoy 1839, pp. 80–81
- ^ "Letter 146 — Darwin, C. R. to Darwin, C. S., 12 Nov (1831)". Darwin Correspondence Project.
- ^ "Letter 147 — Darwin, C. R. to Henslow, J. S., 15 (Nov 1831)". Darwin Correspondence Project.
- ^ Keynes 2001, p. 8
- ^ a b c FitzRoy 1839a, p. 298
- ^ R. B. Forbes (1853). Shipwreck by lightning: Papers relative to Harris lightning conductors. Sleeper & Rogers. pp. 80–81, 85.
Further reading
- Barlow, Nora ed. (1967). "Darwin and Henslow. The growth of an idea". London: Bentham-Moxon Trust, John Murray.
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(help) - FitzRoy, Robert (1839). "Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Proceedings of the second expedition, 1831-36, under the command of Captain Robert Fitz-Roy, R.N." II. London: Henry Colburn.
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- Keynes, Richard (2001). "Charles Darwin's Beagle Diary". Cambridge University Press.
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