The temperature on May 1, 1915 was between 4.5 °C and 19.4 °C and averaged 13.2 °C. There was 7.3 hours of sunshine (49%). The average windspeed was 3 Bft (moderate breeze) and was prevailing from the southwest. Source: KNMI
In The Netherlands , there was from August 29, 1913 to September 9, 1918 the cabinet Cort van der Linden, with Mr. P.W.A. Cort van der Linden (liberaal) as prime minister.
January 21 » Kiwanis International is founded in Detroit.
January 28 » An act of the U.S. Congress creates the United States Coast Guard as a branch of the United States Armed Forces.
January 31 » World War I: Germany is the first to make large-scale use of poison gas in warfare in the Battle of Bolimów against Russia.
February 12 » In Washington, D.C., the first stone of the Lincoln Memorial is put into place.
April 22 » The use of poison gas in World War I escalates when chlorine gas is released as a chemical weapon in the Second Battle of Ypres.
May 24 » World War I: Italy declares war on Austria-Hungary, joining the conflict on the side of the Allies.
Day of death April 23, 1964
The temperature on April 23, 1964 was between 5.2 °C and 12.3 °C and averaged 8.5 °C. There was 10.3 mm of rain during 4.4 hours. There was 2.1 hours of sunshine (15%). The heavily clouded was. The average windspeed was 3 Bft (moderate breeze) and was prevailing from the southwest. Source: KNMI
January 11 » Surgeon General of the United States Dr. Luther Terry, M.D., publishes the landmark report Smoking and Health: Report of the Advisory Committee to the Surgeon General of the United States saying that smoking may be hazardous to health, sparking national and worldwide anti-smoking efforts.
January 12 » Rebels in Zanzibar begin a revolt known as the Zanzibar Revolution and proclaim a republic.
April 11 » Brazilian Marshal Humberto de Alencar Castelo Branco is elected President by the National Congress.
June 10 » United States Senate breaks a 75-day filibuster against the Civil Rights Act of 1964, leading to the bill's passage.
October 1 » The Free Speech Movement is launched on the campus of the University of California, Berkeley.
November 28 » Vietnam War: National Security Council members agree to recommend that U.S. President Lyndon B. Johnson adopt a plan for a two-stage escalation of bombing in North Vietnam.
When copying data from this family tree, please include a reference to the origin: Joop Klavers, "Family tree Klavers", database, Genealogy Online (https://www.genealogieonline.nl/stamboom_klavers/I486294.php : accessed January 13, 2026), "Harm Potse (± 1894-1964)".
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