Alexander Graham Bell : biography

Bell worked extensively in medical research and invented techniques for teaching speech to the deaf. During his Volta Laboratory period, Bell and his associates considered impressing a magnetic field on a record as a means of reproducing sound. Although the trio briefly experimented with the concept, they could not develop a workable prototype. They abandoned the idea, never realizing they had glimpsed a basic principle which would one day find its application in the tape recorder, the hard disc and floppy disc drive and other magnetic media.

Bell’s own home used a primitive form of air conditioning, in which fans blew currents of air across great blocks of ice. He also anticipated modern concerns with fuel shortages and industrial pollution. Methane gas, he reasoned, could be produced from the waste of farms and factories. At his Canadian estate in Nova Scotia, he experimented with composting toilets and devices to capture water from the atmosphere. In a magazine interview published shortly before his death, he reflected on the possibility of using solar panels to heat houses.

Photophone

Bell and his assistant Charles Sumner Tainter jointly invented a wireless telephone, named a photophone, which allowed for the transmission of both sounds and normal human conversations on a beam of light.Bruce 1990, p. 336.Jones, Newell. San Diego Evening Tribune, July 31, 1937. Retrieved from the University of San Diego History Department website, November 26, 2009. Both men later became full associates in the Volta Laboratory Association.

On June 21, 1880, Bell’s assistant transmitted a wireless voice telephone message a considerable distance, from the roof of the Franklin School in Washington, D.C., to Bell at the window of his laboratory, some away, 19 years before the first voice radio transmissions.Carson 2007, pp. 76–78.Bruce 1990, p. 338.Groth, Mike. Amateur Radio magazine, Wireless Institute of Australia, Melbourne, April 1987, pp. 12–17 and May 1987, pp. 13–17.Mims 1982, p. 11.

Bell believed the photophone’s principles were his life’s "greatest achievement", telling a reporter shortly before his death that the photophone was "the greatest invention [I have] ever made, greater than the telephone".Phillipson, Donald J.C., and Laura Neilson. The Canadian Encyclopedia online. Retrieved: August 6, 2009. The photophone was a precursor to the fiber-optic communication systems which achieved popular worldwide usage in the 1980s.Morgan, Tim J. "The Fiber Optic Backbone". University of North Texas, 2011.Miller, Stewart E. American Scientist, Sigma Xi, The Scientific Research Society, Vol. 72, No. 1, January–February 1984, pp. 66-71. Its master patent was issued in December 1880, many decades before the photophone’s principles came into popular use.

Metal detector

Bell is also credited with the invention of the metal detector in 1881. The device was quickly put together in an attempt to find the bullet in the body of US President James Garfield. According to some accounts, the metal detector worked flawlessly in tests but did not find the assassin’s bullet partly because the metal bed frame on which the President was lying disturbed the instrument, resulting in static.Grosvenor and Wesson 1997, p. 107. The president’s surgeons, who were skeptical of the device, ignored Bell’s requests to move the president to a bed not fitted with metal springs. Alternatively, although Bell had detected a slight sound on his first test, the bullet may have been lodged too deeply to be detected by the crude apparatus.

Bell’s own detailed account, presented to the American Association for the Advancement of Science in 1882, differs in several particulars from most of the many and varied versions now in circulation, most notably by concluding that extraneous metal was not to blame for failure to locate the bullet. Perplexed by the peculiar results he had obtained during an examination of Garfield, Bell "…proceeded to the Executive Mansion the next morning…to ascertain from the surgeons whether they were perfectly sure that all metal had been removed from the neighborhood of the bed. It was then recollected that underneath the horse-hair mattress on which the President lay was another mattress composed of steel wires. Upon obtaining a duplicate, the mattress was found to consist of a sort of net of woven steel wires, with large meshes. The extent of the [area that produced a response from the detector] having been so small, as compared with the area of the bed, it seemed reasonable to conclude that the steel mattress had produced no detrimental effect." In a footnote, Bell adds that "The death of President Garfield and the subsequent post-mortem examination, however, proved that the bullet was at too great a distance from the surface to have affected our apparatus."Bell, A. 1882. "Upon the electrical experiments to determine the location of the bullet in the body of the late President Garfield; and upon a successful form of induction balance for the painless detection of metallic masses in the human body." . Private printing of "A paper read before the American Association for the Advancement of Science, at the Montreal meeting, August 1882." See page 33. Retrieved 29 April 2013.