Tombaugh discovered nearly 800 asteroids during his search for Pluto and years of follow-up searches looking for another candidate for the postulated Planet X. Tombaugh is also credited with the discovery of comet C / 1931 AN, though its orbit is currently unknown.

* Chaconne in D minor ; transcribed from the Chaconne in C sharp minor from 1925 ; completed 1931 ; Manuscript

Canada did not have any foreign embassies until its first one was established in Washington, D. C., in 1931.

* Macchi M. C. 72-Schneider Trophy racing seaplane ( 1931 )

R. C. Gorman ( 1931 – 2005 ) was an internationally renowned artist of the Navajo Nation, sometimes called the " Picasso " of the American Indian Arts.

:* 1931: Payment Deferred adapted from the novel by C. S. Forester

This is equivalent to saying that each positive integer occurs only finitely many times as a difference of perfect powers: more generally, in 1931 Pillai conjectured that for fixed positive integers A, B, C the equation has only finitely many solutions ( x, y, m, n ) with ( m, n ) ≠ ( 2, 2 ).

The meeting, held in Cambridge, United Kingdom, concluded with the formalization of the CIE 1931 XYZ color space and definitions of the 1931 CIE 2 ° standard observer with the corresponding color matching functions, and standard illuminants A, B, and C.

In 1931, Brigadier General Randolph C. Berkeley appointed del Valle to the " Landing Operations Text Board " in Quantico, the first organizational step taken by the Marines to develop a working doctrine for amphibious assault.

In the sound era McCarey ventured into feature-film direction, working with many of the biggest stars of the era, including Gloria Swanson ( Indiscreet, 1931 ), Eddie Cantor ( The Kid From Spain, 1932 ), the Marx Brothers ( Duck Soup, 1933 ), W. C. Fields ( Six of a Kind, 1934 ), Mae West ( Belle of the Nineties, 1934 ), and Harold Lloyd ( The Milky Way, 1936 ).

44 ° C ) in September, set in 1931, and 98 ° F ( approx.

In 1931, Sydney Chapman and Vincenzo C. A. Ferraro wrote an article, A New Theory of Magnetic Storms, that sought to explain the phenomenon of geomagnetic storms.

In 1931, Jay C. instituted the Annual Wage Plan: under this plan, employees were paid weekly and they were guaranteed 52 weeks ' notice before termination of employment.

District of Vorkloster: Maria Hilf parish church ( 1925 – 1931, C. Holzmeister, interior from 1980 ) and Cistercian monastery of Mehrerau.

Chester was home to Chester City F. C., who were founded in 1885 and elected to the Football League in 1931, and played at their Sealand Road stadium until 1990, spending two years playing in Macclesfield before returning to the city to the new Deva Stadium – which straddles the border of England and Wales – in 1992.

* Zapata ( oil painting ), 1931, Hirshhorn Museum and Sculpture Garden, Smithsonian, Washington, D. C.

In 1931, after a series of negotiations, 21 works of art from the Hermitage were acquired by Andrew W. Mellon, who later donated them to form a nucleus of the National Gallery of Art in Washington, D. C. ( See also Soviet sale of Hermitage paintings ).

* Joseph C. Chamberlin ( 1931 ): The Arachnid Order Chelonethida.

* C. l. atlantis ( Bannerman, 1931 ) of Madeira, the Azores and Cape Verde, is a very variable population with chequered upperparts obscuring the black wingbars, and is almost certainly derived from feral pigeons.

During Pupin's tenure, Harold C. Urey, in his work with the hydrogen isotope deuterium demonstrated the existence of heavy water, the first major scientific breakthrough in the newly founded laboratories ( 1931 ).

Pinking Shears ( Model C ), Filed September 19, 1931 ; Issued August 14, 1934

The extreme high and low temperatures are 37. 8 ° C ( 100 ° F ), recorded on July 4, 1911 ; July 1, 1931 ; Aug 26, 1948, and − 32. 8 ° C (- 27 ° F ), recorded on January 25, 1884.

and Moore, R. C., 1931, " The Kaiparowits region, a geographic and geologic reconnaissance of parts of Utah and Arizona ", U. S. Geological Survey Professional Paper, 164, 16 p.

* Gramophone Company, a British record company, existing from 1897 to 1931

In 1931, at the depth of the Great Depression, the Pepsi-Cola Company entered bankruptcy – in large part due to financial losses incurred by speculating on wildly fluctuating sugar prices as a result of World War I.

* 1931 – The Texas Company ( Texaco's corporate name ) purchases Indian Oil Company, based in Illinois, a move that expands Texaco's refining and marketing base in the Midwest and also gives Texaco the rights to Indian's manufacturing processes of Havoline " Wax Free " motor oil, which becomes a Texaco product and provides the company with a higher-quality motor oil product.

In 1931, Stanolind completed its acquisition of Sinclair Pipeline and also acquired the Sinclair Crude Oil Purchasing Company.

Jesse Boot, 1st Baron Trent ( 2 June 1850 – 13 June 1931 ) transformed The Boots Company, founded by his father, John Boot, into a national retailer, which branded itself as " Chemists to the Nation ", before he sold out his controlling interest to American investors in 1920.

In 1931 Columbia merged with the Gramophone Company to form Electric & Musical Industries Ltd ( EMI ).

New York: Rand McNally & Company, 1931.

* Excelsior Motor Manufacturing & Supply Company ( Chicago, IL ), a U. S. motorcycle manufacturer operating in Chicago from 1907 to 1931

In 1931, the Ford Motor Company relocated to a site at Dagenham, and in 1932 the District Line was extended to Upminster ; bringing further development to the area.

The Copper Queen operated in Douglas from 1904 until 1931, when the Phelps Dodge Corporation purchased the Calumet and Arizona Company and took over their smelter.

In 1931, as a memorial to Ned, Petroleum Securities Company, Doheny's family-owned business, made a gift of to the State of California, which is now Doheny State Park.

Kingsford was the site of a Ford Motor Company factory which built wooden station station wagon bodies beginning in 1931.

From 1881 to 1931, the Hastings Goldbeating Company was located in the Borough employing women to pound one-inch strips of gold into gossamer-thin sheets used for decorative arts.

The W. F. Hall Printing Company of Chicago bought Art Color in 1931, and ran it until 1968, when it closed the plant there.

The Webster Citizens Company ice house stood on the west shore of the Upper Lake with a three car rail siding to serve it, and was listed as a railroad business as late as 1931.

Still, the Lima Refinery has survived, continuing to operate for more than 125 years under a succession of owners — Solar Refining Company ( 1886 ), a subsidiary of Standard Oil until the breakup in 1911, SOHIO ( 1931 ), British Petroleum ( 1987 ), Clark USA ( 1998 ), Premcor ( 2000 ), Valero Energy Corporation ( 2005 ), and most recently Husky Energy ( 2007 ).

Edward Hines bought the railroad and lumber company from Herrick in 1928, and a post office named Hines was established in 1931 to serve the Edward Hines Lumber Company mill and surrounding community.

* 1931 Opening of the Ravenswood Glass Novelty Company (" The Marble Factory ").

The Fairwater Hemp Company closed in 1931.

Electric and Musical Industries Ltd was formed in March 1931 by the merger of the Columbia Graphophone Company and the Gramophone Company, with its " His Master's Voice " record label, firms that have a history extending back to the origins of recorded sound.

When the Gramophone Company merged with the Columbia Graphophone Company ( including Columbia's subsidiary label Parlophone ) in 1931, the new Anglo-American group was incorporated as Electric & Musical Industries Ltd. At this point RCA had a majority shareholding in the new company, giving RCA chair David Sarnoff a seat on the EMI board.

The investor's fortune began dwindling by 1931 ; Insull then sold the licenses of both stations to National Broadcasting Company.