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 31 » The arrival at Plymouth of Tāwhiao, King of Maoris, to claim the protection of Queen Victoria.
June 16 » The first purpose-built roller coaster, LaMarcus Adna Thompson's "Switchback Railway", opens in New York's Coney Island amusement park.
August 5 » The cornerstone for the Statue of Liberty is laid on Bedloe's Island (now Liberty Island) in New York Harbor.
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.
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 21 » The first Monte Carlo Rally takes place.
January 26 » Glenn Curtiss flies the first successful American seaplane.
April 29 » Tsinghua University, one of mainland China's leading universities, is founded.
November 1 » World's first combat aerial bombing mission takes place in Libya during the Italo-Turkish War. Second Lieutenant Giulio Gavotti of Italy drops several small bombs.
November 5 » After declaring war on the Ottoman Empire on September 29, 1911, Italy annexes Tripoli and Cyrenaica.
December 27 » "Jana Gana Mana", the national anthem of India, is first sung in the Calcutta Session of the Indian National Congress.
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 14 » Alam Ara, India's first talking film, is released.
March 19 » Gambling is legalized in Nevada.
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.
August 24 » France and the Soviet Union sign a neutrality pact.
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 March 6, 2026), "Roelf Potze (1884-1931)".
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