Editing Amos Dolbear

{{short description|American physicist}}
{{Use mdy dates|date=March 2022}}
{{Infobox scientist
| name = Amos Dolbear 
| image = Amosedolbear1880.jpg
| caption = Amos Dolbear, c. 1880
| birth_date = {{Birth date|1837|11|10|mf=yes}}
| birth_place = [[Norwich, Connecticut]]
| death_date = {{Death date and age|1910|2|23|1837|11|10|mf=yes}}
| death_place = [[Medford, Massachusetts]]
| known_for         = [[Dolbear's law]]
| signature = Signature of Amos Emerson Dolbear (1837–1910).svg
}}
'''Amos Emerson Dolbear''' ({{IPAc-en|ˈ|eɪ|m|ɒ|s|_|ˈ|ɛ|m|ər|s|ən|_|ˈ|d|ɒ|l|b|ɛər}};<ref>{{cite web|url=https://www.dictionary.net/amos%20emerson%20dolbear|title=What is the definition of Amos emerson dolbear?|website=Dictionary.net|access-date=January 24, 2024}}</ref> November 10, 1837 – February 23, 1910) was an American [[physicist]] and [[inventor]].  Dolbear researched electrical spark conversion into [[sound waves]] and [[electrical impulses]]. He was a professor at [[University of Kentucky]] in [[Lexington, Kentucky|Lexington]] from 1868 until 1874.  In 1874 he became the chair of the physics department at [[Tufts University]] in [[Medford, Massachusetts]].<ref>{{Cite web | url=http://dl.tufts.edu/catalog/tei/tufts:UA069.005.DO.00001/chapter/D00047 | title=Tufts Digital Library | access-date=2014-04-14 | archive-url=https://web.archive.org/web/20140104231056/http://dl.tufts.edu/catalog/tei/tufts:UA069.005.DO.00001/chapter/D00047 | archive-date=2014-01-04 | url-status=dead }}</ref> He is known for his 1882 invention of a system for transmitting [[telegraph]] signals without wires.  In 1899 his patent for it was purchased in an unsuccessful attempt to interfere with [[Guglielmo Marconi]]'s [[wireless telegraphy]] patents in the United States.

==Biography==
Amos Dolbear was born in [[Norwich, Connecticut|Norwich]], Connecticut, on November 10, 1837.<ref name=Passes>{{Cite news |url=https://www.newspapers.com/clip/97604617/prof-dolbear-passes-away/ |title=Prof Dolbear Passes Away |newspaper=[[The Boston Globe]] |location=Medford |page=9 |date=1910-02-24 |access-date=2022-03-14 |via=Newspapers.com}}</ref> He was a graduate of [[Ohio Wesleyan University]], in [[Delaware, Ohio|Delaware]], Ohio. While a student there, he had made a "talking telegraph" and invented a receiver containing two features of the modern telephone: a permanent magnet and a metallic diaphragm that he made from a [[tintype]]. He invented the first telephone receiver with a permanent magnet in 1865, 11 years before [[Alexander Graham Bell]] patented his model.{{citation needed|date=November 2021}} Later, Dolbear couldn't prove his claim, so Bell kept the patent. Dolbear lost his case before the U. S. Supreme Court, (''Dolbear et al. v. American Bell Telephone Company''). The June 18, 1881, edition of ''[[Scientific American]]'' reported:
{{Blockquote|[...] had he been observant of patent office formalities, it is possible that the speaking telephone, now so widely credited to Mr. Bell would be garnered among his own laurels.<ref name="Dolbear">{{cite journal
  | last1  = Dolbear
  | first1 = Amos
  | title = A new telephone system
  | journal = Scientific American
  | volume = 44
  | issue = 25
  | pages = 384
  | publisher = The Scientific American Publishing Co.
  | date = 18 June 1881
  | url = https://www.jstor.org/stable/26075824
  | issn =
  | doi =
  | jstor = 26075824
  | id =
  | accessdate = 15 June 2022}}</ref>}}

In 1876, Dolbear patented a magneto electric telephone. He patented a static telephone in 1879.

[[Image:Dolbear's wireless telephone circuit 1886.png|upright=1.5|thumb|Circuit of Dolbear's wireless telephone, from his 1882 patent. The [[transmitter]] (A) consisted of an electrostatic [[microphone]] (T) and [[electric battery|battery]] in the primary circuit of an [[induction coil]] (G). One side of the high voltage secondary winding is [[ground (electricity)|earthed]] (C) the other side connected to an elevated [[capacitance]] (H1). The receiver (B) consists of a battery, [[earphone]] (R) and capacitor (H) connected in series between an elevated capacitor (H2) and earth (D).]]
In 1883, Dolbear was able to communicate over a distance of a quarter of a mile without wires in the Earth.<ref name="Fahie">{{cite book
  | last = Fahie
  | first = John Joseph
  | title = A History of Wireless Telegraphy, 3rd Ed.
  | publisher = Dodd, Mead, and Co.
  | date = 1902
  | location = New York
  | pages = 94–99
  | language = 
  | url = https://books.google.com/books?id=alIXAAAAYAAJ
  | doi = 
  | id = 
  | isbn = 
  | mr = 
  | zbl = 
  | jfm =}} [https://archive.org/details/ahistorywireles01fahigoog/page/n123/mode/2up Alt URL]</ref><ref name="Sarkar">{{cite book
| last1= Sarkar
| first1= T. K.
| last2= Mailloux
| first2= Robert
| last3= Oliner
| first3= Arthur A.
| title= History of Wireless
| publisher= John Wiley and Sons
| date= 2006
| pages= 254–255
| url= https://archive.org/stream/HistoryOfWireless#page/n260/mode/2up
| isbn= 978-0471783015
}}</ref> His device relied on conduction in the ground, which was different from later radio transmissions that used electromagnetic radiation.{{citation needed|date=November 2021}} He received a U.S. patent for a wireless telegraph in March of that year. His set-up used phones grounded by metal rods poked into the earth. His transmission range was at least as much as a half a mile<ref>"Mode of Electric communication" {{US patent|350299}} October 5, 1886. Lines 51–55.</ref> and he received a patent for this device, {{US patent|350299}}, in 1886. (He did not patent his system in Europe.)

In 1899, The New England Wireless Telegraph and Telephone Company, a subsidiary of the American Wireless Telephone and Telegraph Company, purchased Dolbear's 1886 patent, and filed a suit against Marconi for infringement.<ref>{{Cite news |url=https://www.newspapers.com/clip/97605099/a-suit-against-marconi/ |title=A Suit Against Marconi |newspaper=[[The Washington Times (1894–1939)|The Washington Times]] |location=New York |page=4 |date=1899-10-18 |access-date=2022-03-14 |via=Newspapers.com}}</ref> However, in March 1901, a United States Circuit Court dismissed the suit.<ref>{{Cite news |url=https://www.newspapers.com/clip/97602708/suit-against-marconi-dismissed/ |title=Suit Against Marconi Dismissed |newspaper=[[New-York Tribune]] |page=7 |date=1901-03-23 |access-date=2022-03-14 |via=Newspapers.com}}</ref> In April 1902, American Wireless petitioned Congress to extend the 1886 patent by ten years, but was unsuccessful, so it duly expired on October 4, 1903.<ref>"Petition of the American Wireless Telegraph and Telegraph Company, of Philadelphia, Pa., Praying the Extension for Ten Years of Letters Patent No. 350,299, Being the Basic Patent for the Art of Wireless Telegraphy and Telephony Granted to Amos Emerson Dolbear in 1886", ''United States Senate Documents, Volume 26 (4245), 57th Congress, 1st Session'', Document No. 346, pages 1–3.</ref> In 1905, the New York Circuit Court further noted that the Dolbear patent was "inoperative, and that, even if operative, it operates by virtue of radically different electrical laws and phenomena" than the radio signaling used by Marconi.<ref>"Marconi Wireless Telegraph Co. of America v. De Forest Wireless Telegraph Co. (Circuit Court, S. D. New York. April 11, 1905.)", ''The Federal Reporter. Volume 138. Cases Argued and Determined in the Circuit Courts of Appeals and Circuit and District Courts of the United States. July–September, 1905'', page 668.</ref>

In 1868 Dolbear (while a professor at Bethany College) invented the electrostatic telephone.{{citation needed|date=November 2021}}  He also invented the opeidoscope (an instrument for visualizing vibration of sound waves, using a mirror mounted on a membrane) and a system of [[incandescent light]]ing.{{citation needed|date=November 2021}} He authored several books, articles, and pamphlets, and was recognized for his contributions to science at both the Paris Exposition in 1881 and the Crystal Palace Exposition in 1882.

In 1897, Dolbear published an article "The Cricket as a Thermometer" that noted the correlation between the ambient temperature and the rate at which [[cricket (insect)|cricket]]s chirp. The formula expressed in that article became known as [[Dolbear's Law]].

In 1899, after the demonstration by Ernest A. Hummel of the telediagraph, an apparatus allowing the transmission of pictures by wire, Dolbear claimed to have invented such an apparatus in 1864 ([https://archive.org/details/norwichbulletin100bull_13/page/n827/mode/2up?q=telediagraph ''Norwich Bulletin'', 26 April 1899]). 

He died at his home in Medford on February 23, 1910.<ref name=Passes/>

In 2008, Kent Biffle of the [[Dallas Morning News]] reported receiving newspaper clippings from a local lawyer and historian on the subject of [[UFO]] sightings in [[Stephenville, Texas]].<ref name=Biffle>{{cite web |first=Kent |last=Biffle |title=Stephenville area's had its share of UFO sightings |url=http://www.dallasnews.com/sharedcontent/dws/news/texassouthwest/stories/DN-biffle_03tex.ART.State.Edition1.4501c2d.html |archive-url= https://web.archive.org/web/20081028162338/http://www.dallasnews.com/sharedcontent/dws/news/texassouthwest/stories/DN-biffle_03tex.ART.State.Edition1.4501c2d.html |url-status=dead |publisher=Dallas Morning News |date=February 4, 2008 |archive-date= October 28, 2008 |access-date=April 26, 2009 }}</ref> Apparently in 1897, widespread newspaper reports of a cigar-shaped flying object started to circulate in the Midwest and Southwest.<ref name=Cohen>{{cite book |title=The great airship mystery: A UFO of the 1890s |last=Cohen |first=Daniel |year=1981 |publisher=Dodd, Mead |isbn=0-396-07990-3 }}</ref><ref name=Busby>{{cite book |title=Solving the 1897 Airship Mystery |last=Busby |first=Michael |date=January 2004 |publisher=Pelican Publishing Company |isbn=1-58980-125-3}}</ref> Responding to sightings previously reported in the Morning News, on April 17, 1897, one respected [[Erath County, Texas|Erath County]] farmer, C.L. McIlhany discovered such a craft had landed on his property, and reported two human operators, a pilot and an engineer, who gave their names as "[[Samuel Escue Tillman|S.E. Tilman]]" and "A.E. Dolbear."<ref name=Biffle/> The two operators performed minor repairs on their electrically powered lighter-than-air craft, then again flew away.<ref name=Cabinet02032008>{{cite web |author=Cabinet of Wonders |title=The Stephenville phantom airship |url=http://www.wunderkabinett.co.uk/damndata/index.php?/archives/1262-The-Stephenville-phantom-airship.html |archive-url=https://web.archive.org/web/20080303052548/http://www.wunderkabinett.co.uk/damndata/index.php?%2Farchives%2F1262-The-Stephenville-phantom-airship.html |url-status=usurped |archive-date=March 3, 2008 |work=Cabinet of Wonders blog |date=February 3, 2008 |access-date=April 26, 2009 }}</ref><ref name=Cabinet02132008>{{cite web |author=Cabinet of Wonders |title=The faces of phantom airship pilots |url=http://www.wunderkabinett.co.uk/damndata/index.php?/archives/1275-The-faces-of-phantom-airship-pilots.html |archive-url=https://web.archive.org/web/20080218175231/http://www.wunderkabinett.co.uk/damndata/index.php?%2Farchives%2F1275-The-faces-of-phantom-airship-pilots.html |url-status=usurped |archive-date=February 18, 2008 |work=Cabinet of Wonders blog |date=February 13, 2008 |access-date=April 26, 2009 }}</ref>

==Publications==
===Books===
* Dolbear, A. E. [https://archive.org/details/artofprojectingm00dolb   ''The Art of Projecting: A manual of experimentation in physics, chemistry, and natural history, with the porte lumière and magic lantern''], Boston, Lee and Shepard, 1877
* Dolbear, A. E. [https://books.google.com/books?id=OqtbAAAAQAAJ   ''The Telephone''], Boston, Lee and Shepard, 1877
* Dolbear, A. E. [https://archive.org/details/telephoneaccount00dolb   ''The Telephone and how to make it''], London, Sampson Lowe, 1878 
* Dolbear, A. E. [https://archive.org/details/matterethermotio00dolb ''Matter, Ether, and Motion''], Boston, Lee and Shepard, 1892
* Dolbear, A. E. [https://books.google.com/books?id=mDcAAAAAYAAJ  '' First Principles of Natural Philosophy''], Boston, Ginn and Co., 1897
* Dolbear, A. E. [https://archive.org/details/modesofmotionorm00dolbiala   ''Modes of Motion: Mechanical conceptions of physical phenomena''], Boston, Lee and Shepard,  1897

===Journal articles===
* "[https://www.jstor.org/stable/2453256 The Cricket as a Thermometer]". ''The American Naturalist'', Vol. 31, No. 371 (November 1897), pp.&nbsp;970–971. Published by The University of Chicago Press for The American Society of Naturalists

===Patents===
* ''[https://patents.google.com/patent/US239742 Apparatus for transmitting sound by electricity]'' {{US patent|239742}} April 5, 1881.

==References==
{{Reflist}}

==External links==
{{commons category|Amos Dolbear (physicist)}}
* {{Gutenberg author | id=33913}}
* {{Internet Archive author |sname=Amos Emerson Dolbear}}
* [https://web.archive.org/web/20140104231056/http://dl.tufts.edu/catalog/tei/tufts:UA069.005.DO.00001/chapter/D00047 Concise Encyclopedia of Tufts History - Dolbear, Amos Emerson, 1837–1910]
* [https://web.archive.org/web/20040709140205/http://www.hsccnh.org/mm/mm076.cfm Roxbury's Professor Dolbear]
* [https://web.archive.org/web/20060317153704/http://worlddmc.ohiolink.edu/Images/Bdg/Hist1MDS/d294/1069655075-11849-25591-46656-216-1983012051.Om2812_004.jpg A portrait of Prof. Dolbear]

{{Authority control}}

{{DEFAULTSORT:Dolbear, Amos Emerson}}
[[Category:1837 births]]
[[Category:1910 deaths]]
[[Category:19th-century American inventors]]
[[Category:20th-century American inventors]]
[[Category:19th-century American physicists]]
[[Category:Ohio Wesleyan University alumni]]
[[Category:University of Kentucky faculty]]
[[Category:Tufts University faculty]]
[[Category:20th-century American physicists]]
[[Category:People from Norwich, Connecticut]]
[[Category:Inventors from Connecticut]]
[[Category:Scientists from Connecticut]]