Editing Rotary dial (section)

==History==
{{Globalize|section|US|date=January 2021}}
[[File:Ericsson Dialog in green.JPG|right|thumb|The LM Ericsson Dialog from the 1960s that remained popular in [[Sweden]] and [[Finland]] up until the 1980s]]
[[File:Bakelittelefon 1947a.jpg|thumb|right|Swedish rotary telephone. The ''0'' precedes ''1''.]]

From as early as 1836 onward, various suggestions and inventions of dials for sending [[telegraph]] signals were reported. After the first commercial telephone exchange was installed in 1878, the need for an automated, user-controlled method of directing a telephone call became apparent. By 1891, numerous inventions were competing for acceptance and 26 patents for dials, push-buttons, and similar mechanisms, specified methods of signalling a destination telephone number. Most inventions involved costly, intricate mechanisms and required the user to perform complex operations.{{Citation needed|date=January 2016}}

The first commercial installation of a telephone dial accompanied the first commercial installation of a 99-line [[automatic telephone exchange]] in [[La Porte, Indiana]], in 1892, which was based on the 1891 Strowger designs. The original dials required complex operational sequences. A workable, albeit error-prone, system was invented by the Automatic Electric Company using three push-buttons on the telephone. These buttons represented the hundreds, tens, and single units of a telephone number. When calling the subscriber number 163, for example, the user had to push the hundreds button once, followed by six presses of the tens button, and three presses of the units button.<ref>Smith, A. B.; Campbell, W. L., ''Automatic Telephony'', New York, [[McGraw-Hill]], 1921, p. 38.</ref> In 1896, this system was supplanted by an automatic ''contact-making machine'', or ''calling device''. Further development continued during the 1890s and the early 1900s in conjunction with improvements in switching technology.

Almon Brown Strowger was the first to file a patent for an automatic telephone exchange on December 21, 1891, which was awarded on November 29, 1892, as {{US patent|486909}}.<ref>{{cite web|url=http://oldphones.com/nytimes.html|title=When Dials Were Round and Clicks Were Plentiful|last=Greenman|first=Catherine|date=October 7, 1999|work=The New York Times|via=oldphones.com|url-status=dead|archive-url=https://web.archive.org/web/20070616024506/http://oldphones.com/nytimes.html|archive-date=2007-06-16}}</ref><ref>{{cite web
|title=Automatic Telephone or Other Electrical Exchange
|publisher=United States Patent and Trademark Office
|url=https://patents.google.com/patent/US486909
}}</ref> The company later developed a rotary dial with lugs on a finger plate instead of holes that interrupted two independent circuits for control of relays in the exchange switch. The pulse train was generated without the control of spring action or a governor on the forward movement of the wheel, which proved to be difficult to operate correctly.

Despite their lack of modern features, rotary dials occasionally find special uses. For instance, the anti-drug [[Fairlawn Coalition]] of the [[Anacostia]] section of Washington, D.C., persuaded the phone company to reinstall rotary-dial [[pay phone]]s in the 1980s to discourage [[loitering]] by drug purchasers, since they lacked a [[telephone keypad]] to leave messages on dealers' [[pager]]s.<ref>{{cite book| pages=[https://archive.org/details/toserveprotectpr00bens/page/n151 123]–124| title=To Serve and Protect: Privatization and Community in Criminal Justice| url=https://archive.org/details/toserveprotectpr00bens| url-access=limited| chapter=Private Justice in America| author=Benson, Bruce L.| isbn=0-8147-1327-0| year=1998| publisher=NYU Press}}</ref> They are also retained for authenticity in historic properties such as the [[U.S. Route 66]] [[Blue Swallow Motel]], which date back to the era of named exchanges and pulse dialing.<ref>{{cite news| author=John Flinn |url=http://www.sfgate.com/travel/article/Route-66-still-has-some-kicks-3922406.php |title=Route 66 still has some kicks |newspaper=[[San Francisco Chronicle]] |date=October 5, 2012 |access-date=2012-10-08}}</ref>