April 30 » J. J. Thomson of the Cavendish Laboratory announces his discovery of the electron as a subatomic particle, over 1,800 times smaller than a proton (in the atomic nucleus), at a lecture at the Royal Institution in London.
July 11 » Salomon August Andrée leaves Spitsbergen to attempt to reach the North Pole by balloon. He later crashes and dies.
August 21 » Oldsmobile, an American automobile manufacturer and marque, is founded.
September 1 » The Tremont Street Subway in Boston opens, becoming the first underground rapid transit system in North America.
September 10 » Lattimer massacre: A sheriff's posse kills 19 unarmed striking immigrant miners in Lattimer, Pennsylvania, United States.
September 11 » After months of pursuit, generals of Menelik II of Ethiopia capture Gaki Sherocho, the last king of Kaffa, bringing an end to that ancient kingdom.
Day of marriage April 18, 1922
The temperature on April 18, 1922 was between 2.7 °C and 9.2 °C and averaged 6.4 °C. There was 1.5 mm of rain. There was 1.3 hours of sunshine (9%). The average windspeed was 4 Bft (moderate breeze) and was prevailing from the north. Source: KNMI
In The Netherlands , there was from September 9, 1918 to September 18, 1922 the cabinet Ruys de Beerenbrouck I, with Jonkheer mr. Ch.J.M. Ruys de Beerenbrouck (RKSP) as prime minister.
In The Netherlands , there was from September 19, 1922 to August 4, 1925 the cabinet Ruys de Beerenbrouck II, with Jonkheer mr. Ch.J.M. Ruys de Beerenbrouck (RKSP) as prime minister.
February 9 » Brazil becomes a member of the Berne Convention copyright treaty.
March 10 » Mahatma Gandhi is arrested in India, tried for sedition, and sentenced to six years in prison, only to be released after nearly two years for an appendicitis operation.
March 26 » The German Social Democratic Party is founded in Poland.
July 15 » Japanese Communist Party is established in Japan.
September 30 » The University of Alabama opens the American football season with a 110–0 victory over the Marion Military Institute, which still stands as Alabama's record for largest margin of victory and as their only 100 point game.
October 28 » Italian fascists led by Benito Mussolini march on Rome and take over the Italian government.
Day of death December 18, 1971
The temperature on December 18, 1971 was between 1.1 °C and 4.9 °C and averaged 2.2 °C. There was -0.1 mm of rain. The almost completely overcast was. The average windspeed was 3 Bft (moderate breeze) and was prevailing from the south. Source: KNMI
January 25 » Idi Amin leads a coup deposing Milton Obote and becomes Uganda's president.
February 8 » The NASDAQ stock market index opens for the first time.
February 9 » Satchel Paige becomes the first Negro League player to be voted into the USA's Baseball Hall of Fame.
February 24 » The All India Forward Bloc holds an emergency central committee meeting after its chairman, Hemantha Kumar Bose, is killed three days earlier. P.K. Mookiah Thevar is appointed as the new chairman.
October 25 » The People's Republic of China replaces the Republic of China at the United Nations.
December 4 » The PNS Ghazi, a submarine belonging to the Pakistan Navy, sinks during the course of the Indo-Pakistani Naval War of 1971.
When copying data from this family tree, please include a reference to the origin: Hans Weening, "Family tree Weening", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-weening/I200754.php : accessed December 28, 2025), "Jan Heitmeijer (1897-1971)".
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