The temperature on June 9, 1884 was about 14.5 °C. There was 0.9 mm of rain. The air pressure was 1 kgf/m2 and came mainly from the west-southwest. The airpressure was 76 cm mercury. The atmospheric humidity was 78%. Source: KNMI
In The Netherlands , there was from April 23, 1884 to April 21, 1888 the cabinet Heemskerk, with Mr. J. Heemskerk Azn. (conservatief) as prime minister.
May 1 » The Federation of Organized Trades and Labor Unions demands the eight-hour work day in the United States.
June 16 » The first purpose-built roller coaster, LaMarcus Adna Thompson's "Switchback Railway", opens in New York's Coney Island amusement park.
October 6 » The Naval War College of the United States is founded in Rhode Island.
October 13 » The International Meridian Conference establishes the meridian of the Greenwich Observatory as the prime meridian.
December 6 » The Washington Monument in Washington, D.C., is completed.
December 10 » Mark Twain's Adventures of Huckleberry Finn is published.
Day of marriage May 6, 1911
The temperature on May 6, 1911 was between 2.7 °C and 13.9 °C and averaged 8.6 °C. There was 12.1 hours of sunshine (80%). The average windspeed was 3 Bft (moderate breeze) and was prevailing from the north. Source: KNMI
January 3 » A gun battle in the East End of London left two dead and sparked a political row over the involvement of then-Home Secretary Winston Churchill.
January 12 » The University of the Philippines College of Law is formally established; three future Philippine presidents are among the first enrollees.
May 21 » President of Mexico Porfirio Díaz and the revolutionary Francisco Madero sign the Treaty of Ciudad Juárez to put an end to the fighting between the forces of both men, concluding the initial phase of the Mexican Revolution.
May 30 » At the Indianapolis Motor Speedway, the first Indianapolis 500 ends with Ray Harroun in his Marmon Wasp becoming the first winner of the 500-mile auto race.
August 29 » The Canadian Naval Service becomes the Royal Canadian Navy.
September 23 » Pilot Earle Ovington makes the first official airmail delivery in America under the authority of the United States Post Office Department
Day of death December 21, 1931
The temperature on December 21, 1931 was between -1.2 °C and 2.0 °C and averaged 0.4 °C. The average windspeed was 3 Bft (moderate breeze) and was prevailing from the east-northeast. Source: KNMI
In The Netherlands , there was from August 10, 1929 to May 26, 1933 the cabinet Ruys de Beerenbrouck III, with Jonkheer mr. Ch.J.M. Ruys de Beerenbrouck (RKSP) as prime minister.
January 7 » Guy Menzies flies the first solo non-stop trans-Tasman flight (from Australia to New Zealand) in 11 hours and 45 minutes, crash-landing on New Zealand's west coast.
January 21 » Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia.
February 20 » The U.S. Congress approves the construction of the San Francisco–Oakland Bay Bridge by the state of California.
March 11 » Ready for Labour and Defence of the USSR, abbreviated as GTO, is introduced in the Soviet Union.
May 7 » The stand-off between criminal Francis Crowley and 300 members of the New York Police Department takes place in his fifth-floor apartment on West 91st Street, New York City.
October 1 » The George Washington Bridge in the United States, linking New Jersey and New York, is opened.
When copying data from this family tree, please include a reference to the origin: J. Ham, "Family tree Ham", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-ham/I1500.php : accessed January 31, 2026), "Roelf Potze (1884-1931)".
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