Editing Alexander Graham Bell (section)

==Later inventions==
[[File:AG Bell 1.jpg|thumb|Alexander Graham Bell in his later years]]
{{more citations needed section|date=July 2022}}
Although Alexander Graham Bell is most often associated with the invention of the telephone, his interests were extremely varied. According to one of his biographers, [[Charlotte Gray (author)|Charlotte Gray]], Bell's work ranged "unfettered across the scientific landscape" and he often went to bed voraciously reading the ''Encyclopædia Britannica'', scouring it for new areas of interest.{{sfn|Gray|2006|p=219}} The range of Bell's inventive genius is represented only in part by the 18 patents granted in his name alone and the 12 he shared with his collaborators. These included 14 for the telephone and telegraph, four for the [[photophone]], one for the [[phonograph]], five for aerial vehicles, four for "hydroairplanes", and two for [[selenium]] cells. Bell's inventions spanned a wide range of interests and included a metal jacket to assist in breathing, the [[audiometer]] to detect minor hearing problems, a device to locate icebergs, investigations on how to separate salt from seawater, and work on finding [[alternative fuel]]s.{{citation needed|date=July 2022}}

Bell worked extensively in [[medical research]] and invented techniques for teaching speech to the deaf. During his [[Volta Laboratory and Bureau|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 medium|magnetic media]].{{citation needed|date=July 2022}}

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 toilet]]s and devices to capture water from the atmosphere. In a magazine article published in 1917, he reflected on the possibility of using [[solar energy]] to heat houses.<ref>{{Cite journal |last=Bell |first=Alexander Graham |date=February 1917 |title=Prizes for the Inventor: Some of the Problems Awaiting Solution |url=https://en.wikisource.org/wiki/National_Geographic_Magazine/Volume_31/Number_2/Prizes_for_the_Inventor |journal=[[National Geographic|The National Geographic Magazine]] |volume=31 |issue=2}}</ref>

===Photophone===
{{Main|Photophone}}
[[File:Photophony1.jpg|thumb|Photophone receiver, one half of Bell's wireless [[optical communication]] system, ca. 1880]]

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]].{{sfn|Bruce|1990|p=336}}<ref name="SDU">{{cite web|last=Jones |first=Newell |url=http://history.sandiego.edu/gen/recording/ar304.html |archive-url=https://web.archive.org/web/20020219111153/http://history.sandiego.edu/gen/recording/ar304.html |url-status=dead |archive-date=February 19, 2002 |title=First 'Radio' Built by San Diego Resident Partner of Inventor of Telephone: Keeps Notebook of Experiences With Bell |location=San Diego, California |website=Evening Tribune |date=July 31, 1937 |access-date=November 26, 2009 }}</ref> Both men later became full associates in the [[Volta Laboratory and Bureau#Laboratory projects|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 (Washington, D.C.)|Franklin School]] in Washington, D.C., to Bell at the window of his laboratory, some {{convert|213|m|round=5|order=flip}} away, 19 years before the first voice radio transmissions.{{sfn|Carson|2007|pp=76–78}}{{sfn|Bruce|1990|p=338}}<ref>{{cite journal|last=Groth |first=Mike |url=http://www.bluehaze.com.au/modlight/GrothArticle1.htm |title=Photophones Revisted |journal=Amateur Radio |date=April 1987 |pages=12–17 |access-date=September 19, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150802001855/http://www.bluehaze.com.au/modlight/GrothArticle1.htm |archive-date=August 2, 2015 }}</ref><ref>{{cite journal |last=Mims III |first=Forest M. |url=https://books.google.com/books?id=zoaSp1BJu50C |title=The First Century of Lightwave Communications |journal=Fiber Optics Weekly Update |date=February 10–26, 1982 |pages=11 of 6–23 }}</ref>

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".<ref>{{cite encyclopedia |last1=Phillipson |first1=Donald J.C. |first2=Laura |last2=Neilson |title=Alexander Graham Bell |encyclopedia=[[The Canadian Encyclopedia]] |publisher=[[Historica Canada]] |edition=online |date=March 4, 2015 |url=https://www.thecanadianencyclopedia.ca/en/article/alexander-graham-bell |access-date=September 19, 2015 |archive-date=September 25, 2015 |archive-url=https://web.archive.org/web/20150925112928/http://www.thecanadianencyclopedia.com/en/article/alexander-graham-bell/ |url-status=live }}</ref> The photophone was a precursor to the [[fiber-optic communication]] systems which achieved popular worldwide usage in the 1980s.<ref>{{cite report|last=Morgan |first=Tim J. |title=The Fiber Optic Backbone |publisher=[[University of North Texas]] |date=2011 |url=https://classes.lt.unt.edu/Summer_10W_2011/LTEC_4550_020/tjm0146/Fiber%20Optic%20Backbone%20.docx |archive-url=https://web.archive.org/web/20150925132141/https://classes.lt.unt.edu/Summer_10W_2011/LTEC_4550_020/tjm0146/Fiber%20Optic%20Backbone%20.docx |url-status=dead |archive-date=September 25, 2015 |access-date=September 19, 2015 }}</ref><ref name="AmericanScientist-1984.V72.No1">{{cite journal |last=Miller |first=Stewart E. |jstor=i27852430 |title=Lightwaves and Telecommunication|journal=[[American Scientist]] |volume=72 |issue=1 |date=January–February 1984 |pages=66–71|bibcode=1984AmSci..72...66M }}</ref> Its master patent was issued in December 1880, many decades before the photophone's principles came into popular use.

===Metal detector===
[[File:Telephone Inventor’s Voice Heard in Restored Recording « Science World.theora.ogv|thumb|Bell's voice, from a Volta Laboratory recording in 1885. Restored by the Smithsonian in 2013.]]

Bell is also credited with developing one of the early versions of a [[metal detector]] through the use of an induction balance, after the [[Assassination of James A. Garfield|shooting]] of [[President of the United States|U.S. President]] [[James A. Garfield]] in 1881. According to some accounts, the metal detector worked flawlessly in tests but did not find [[Charles J. Guiteau|Guiteau]]'s bullet, partly because the metal bed frame on which the President was lying disturbed the instrument, resulting in static.{{sfn|Grosvenor|Wesson|1997|p=107}} Garfield's surgeons, led by self-appointed chief physician [[Doctor Willard Bliss]], were sceptical of the device, and ignored Bell's requests to move the President to a bed not fitted with metal springs.{{sfn|Grosvenor|Wesson|1997|p=107}} 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.{{sfn|Grosvenor|Wesson|1997|p=107}}

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, 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 [[White House|Executive Mansion]] the next morning&nbsp;... 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, "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."<ref>{{Cite journal |last=Bell |first=Alexander Graham |date=1882 |title=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 |journal=American Journal of Science |volume=25 |issue=145 |pages=22–61 |url=https://archive.org/details/uponelectricalex00bell |access-date=April 29, 2013 |bibcode=1883AmJS...25...22B |doi=10.2475/ajs.s3-25.145.22 |s2cid=130896535 }}</ref>

===Hydrofoils===
{{Main|HD-4}}
[[File:Bell HD-4.jpg|thumb|Bell's [[HD-4]] on a test run ca. 1919]]

The March 1906 ''[[Scientific American]]'' article by American pioneer William E. Meacham explained the basic principle of [[hydrofoil]]s and [[Hydroplane (boat)|hydroplanes]]. Bell considered the invention of the hydroplane as a very significant achievement. Based on information gained from that article, he began to sketch concepts of what is now called a hydrofoil boat. Bell and assistant [[Frederick W. Baldwin|Frederick W. "Casey" Baldwin]] began hydrofoil experimentation in the summer of 1908 as a possible aid to airplane takeoff from water. Baldwin studied the work of the Italian inventor [[Enrico Forlanini]] and began testing models. This led him and Bell to the development of practical hydrofoil watercraft.

During his world tour of 1910–11, Bell and Baldwin met with Forlanini in France. They had rides in the Forlanini hydrofoil boat over [[Lake Maggiore]]. Baldwin described it as being as smooth as flying. On returning to Baddeck, a number of initial concepts were built as experimental models, including the ''Dhonnas Beag'' (Scottish Gaelic for 'little devil'), the first self-propelled Bell-Baldwin hydrofoil.{{sfn|Boileau|2004|p=18}} The experimental boats were essentially proof-of-concept prototypes that culminated in the more substantial [[HD-4]], powered by [[Renault]] engines. A top speed of {{convert|54|mph|km/h}} was achieved, with the hydrofoil exhibiting rapid acceleration, good stability, and steering, along with the ability to take waves without difficulty.{{sfn|Boileau|2004|pp=28–30}}

In 1913, Dr. Bell hired Walter Pinaud, a Sydney yacht designer and builder as well as the proprietor of Pinaud's Yacht Yard in [[Westmount, Nova Scotia]], to work on the pontoons of the HD-4. Pinaud soon took over the boatyard at Bell Laboratories on Beinn Bhreagh, Bell's estate near [[Baddeck, Nova Scotia]]. Pinaud's experience in boatbuilding enabled him to make useful design changes to the HD-4. After the First World War, work began again on the HD-4. Bell's report to the [[United States Navy|U.S. Navy]] permitted him to obtain two {{convert|350|hp|kW|abbr=off|adj=on}} engines in July 1919. On September 9, 1919, the HD-4 set a world marine speed record of {{convert|70.86|mph|km/h|abbr=off}},{{sfn|Boileau|2004|p=30}} a record which stood for ten years.

===Aeronautics===
{{Main|Aerial Experiment Association|AEA Silver Dart}}
[[File:AEA Silver Dart.jpg|thumb|AEA Silver Dart {{c.|1909}}]]

In 1891, Bell had begun experiments to develop motor-powered heavier-than-air aircraft. The AEA was first formed as Bell shared the vision to fly with his wife, who advised him to seek "young" help as Bell was at the age of 60.

In 1898, Bell experimented with [[tetrahedral]] [[box kite]]s and wings constructed of multiple compound [[tetrahedral kite]]s covered in maroon silk.{{refn|Bell was inspired in part by Australian aeronautical engineer [[Lawrence Hargrave]]'s work with man-carrying box kites.<ref>{{cite book |title=Technical Gazette |location=New South Wales, Australia |date=1924 |page=46}}</ref> Hargrave declined to take patents on his inventions, similar to Bell's decision not to file patents on some of his inventions. Bell also chose maroon-coloured silk as it would show up clearly against the light-coloured sky in his photographic studies.|group="N"}} The tetrahedral wings were named ''Cygnet'' I, II, and III, and were flown both unmanned and manned (''Cygnet I'' crashed during a flight carrying Selfridge) in the period from 1907 to 1912. Some of Bell's kites are on display at the [[Alexander Graham Bell honors and tributes|Alexander Graham Bell National Historic Site]].<ref>[http://ns1763.ca/victco/bellmusbbm.html "Nova Scotia's Electric Scrapbook."] {{webarchive |url=https://web.archive.org/web/20090417080338/http://ns1763.ca/victco/bellmusbbm.html |date=April 17, 2009 }} ''ns1763.ca''. Retrieved: December 29, 2009.</ref>

Bell was a supporter of [[aerospace engineering]] research through the [[Aerial Experiment Association]] (AEA), officially formed at Baddeck, Nova Scotia, in October 1907 at the suggestion of his wife [[Mabel Gardiner Hubbard|Mabel]] and with her financial support after the sale of some of her real estate.<ref>{{cite news |last=Gillis |first=Rannie |url=http://www.capebretonpost.com/Columnists/2008-09-29/article-781848/Mabel-Bell-was-a-focal-figure-in-the-first-flight-of-the-Silver-Dart/1 |title=Mabel Bell Was A Focal Figure In The First Flight of the Silver Dart |work=Cape Breton Post |location=Sydney, Nova Scotia |date=September 29, 2008 |access-date=June 12, 2010 |url-status=dead |archive-url=https://archive.today/20160724050315/http://www.capebretonpost.com/Columnists/2008-09-29/article-781848/Mabel-Bell-was-a-focal-figure-in-the-first-flight-of-the-Silver-Dart/1 |archive-date=July 24, 2016  }}</ref> The AEA was headed by Bell and the founding members were four young men: American [[Glenn H. Curtiss]], a motorcycle manufacturer at the time and who held the title "world's fastest man", having ridden his self-constructed motor bicycle around in the shortest time, and who was later awarded the [[Scientific American|Scientific American Trophy]] for the first official one-kilometre flight in the [[Western hemisphere]], and who later became a world-renowned airplane manufacturer; Lieutenant [[Thomas Selfridge]], an official observer from the U.S. Federal government and one of the few people in the army who believed that aviation was the future; [[Frederick W. Baldwin]], the first Canadian and first British subject to pilot a public flight in [[Hammondsport, New York|Hammondsport]], New York; and [[J. A. D. McCurdy]]–Baldwin and McCurdy being new engineering graduates from the [[University of Toronto]].<ref>{{cite magazine |date=February 27, 1959|title=Canada's Golden Anniversary |magazine=[[Flight International|Flight]] |volume=75|issue=2614|page=280|url= http://www.flightglobal.com/pdfarchive/view/1959/1959%20-%200579.html|access-date=August 28, 2013}}</ref>

The AEA's work progressed to heavier-than-air machines, applying their knowledge of kites to gliders. Moving to Hammondsport, the group then designed and built the ''[[AEA Red Wing|Red Wing]]'', framed in bamboo and covered in red silk and powered by a small [[Engine cooling|air-cooled]] engine.<ref>{{cite book |last=Phillips |first=Allan |title=Into the 20th Century: 1900/1910 |series=(Canada's Illustrated Heritage) |location=Toronto, Ontario |publisher=Natural Science of Canada |date=1977 |page=95 |isbn=978-0-919644-22-9 }}</ref> On March 12, 1908, over [[Keuka Lake]], the biplane lifted off on the first public flight in North America.{{refn|"Selfridge Aerodrome Sails Steadily for {{convert|319|ft|m}}." ''[[The Washington Post]]'' May 13, 1908.|group=N}}{{refn| At 25 to 30 Miles an Hour. First Public Trip of Heavier-than-air Car in America. Professor Alexander Graham Bell's New Machine, Built After Plans by Lieutenant Selfridge, Shown to Be Practicable by Flight Over [[Keuka Lake]]. Portion of Tail Gives Way, Bringing the Test to an End. Views of an Expert. [[Hammondsport, New York|Hammondsport]], New York, March 12, 1908.|group=N}} The innovations that were incorporated into this design included a cockpit enclosure and [[Rudder|tail rudder]] (later variations on the original design would add ailerons as a means of control). One of the AEA's inventions, a practical  [[Aileron#Wingtip ailerons|wingtip form of the aileron]], was to become a standard component on all aircraft.{{refn|The aileron had been conceived of as early as 1868 by British inventor [[Matthew Piers Watt Boulton|M.P.W. Boulton]] and was also created independently by [[Robert Esnault-Pelterie]] and several others.|group="N"}} The ''White Wing'' and ''June Bug'' were to follow and by the end of 1908, over 150 flights without mishap had been accomplished. However, the AEA had depleted its initial reserves and only a [[Mabel Gardiner Hubbard#Support to aeronautical research|$15,000 grant from Mrs. Bell]] allowed it to continue with experiments.{{sfn|Phillips|1977|p=96}} Lt. Selfridge had also become the first person killed in a powered heavier-than-air flight in a crash of the [[Wright Model A|Wright Flyer]] at [[Fort Myer]], [[Virginia]], on September 17, 1908.

Their final aircraft design, the ''[[AEA Silver Dart|Silver Dart]]'', embodied all of the advancements found in the earlier machines. On February 23, 1909, Bell was present as the ''Silver Dart'' flown by J. A. D. McCurdy from the frozen ice of Bras d'Or made the first aircraft flight in Canada.<ref>{{cite magazine |date=October 19, 1956|title=Link with Canadian Pioneers |magazine=[[Flight International|Flight]] |volume=70|issue=2491|page=642|url= http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%201488.html|access-date=August 28, 2013}}</ref> Bell had worried that the flight was too dangerous and had arranged for a doctor to be on hand. With the successful flight, the AEA disbanded and the ''Silver Dart'' would revert to Baldwin and McCurdy, who began the Canadian Aerodrome Company and would later demonstrate the aircraft to the [[Canadian Army]].{{sfn|Phillips|1977|pp=96–97}}