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.
March 13 » The Siege of Khartoum begins. It lasts until January 26, 1885.
April 20 » Pope Leo XIII publishes the encyclical Humanum genus.
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.
November 1 » The Gaelic Athletic Association is set up in Hayes's Hotel in Thurles, County Tipperary.
December 6 » The Washington Monument in Washington, D.C., is completed.
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
March 25 » In New York City, the Triangle Shirtwaist Factory fire kills 146 garment workers.
March 29 » The M1911 .45 ACP pistol becomes the official U.S. Army side arm.
May 9 » The works of Gabriele D'Annunzio are placed in the Index of Forbidden Books by the Vatican.
June 28 » The Nakhla meteorite, the first one to suggest signs of aqueous processes on Mars, falls to Earth, landing in Egypt.
August 21 » The Mona Lisa is stolen by Vincenzo Peruggia, a Louvre employee.
September 25 » An explosion of badly degraded propellant charges on board the French battleship Liberté detonates the forward ammunition magazines and destroys the ship.
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.
March 23 » Bhagat Singh, Shivaram Rajguru and Sukhdev Thapar are hanged for the killing of a deputy superintendent of police during the Indian independence movement.
March 26 » Ho Chi Minh Communist Youth Union is founded in Vietnam.
April 14 » The Spanish Cortes deposes King Alfonso XIII and proclaims the Second Spanish Republic.
May 14 » Five unarmed civilians are killed in the Ådalen shootings, as the Swedish military is called in to deal with protesting workers.
October 21 » A secret society in the Imperial Japanese Army launches an abortive coup d'état attempt.
December 11 » Statute of Westminster 1931: The British Parliament establishes legislative equality between the UK and the Dominions of the Commonwealth—Australia, Canada, Newfoundland, New Zealand, South Africa, and Ireland.
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 February 1, 2026), "Roelf Potze (1884-1931)".
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