The temperature on December 23, 1905 was between 3.2 °C and 6.3 °C and averaged 4.6 °C. The average windspeed was 2 Bft (weak wind) and was prevailing from the south-southwest. Source: KNMI
In The Netherlands , there was from August 1, 1901 to August 16, 1905 the cabinet Kuijper, with Dr. A. Kuijper (AR) as prime minister.
In The Netherlands , there was from August 17, 1905 to February 11, 1908 the cabinet De Meester, with Mr. Th. de Meester (unie-liberaal) as prime minister.
June 7 » Norway's parliament dissolves its union with Sweden. The vote was confirmed by a national plebiscite on August 13 of that year.
August 20 » Sun Yat-sen, Chinese revolutionary, forms the first chapter of T'ung Meng Hui, a union of all secret societies determined to bringing down the Manchus.
September 5 » Russo-Japanese War: In New Hampshire, United States, the Treaty of Portsmouth, mediated by U.S. President Theodore Roosevelt, ends the war.
October 5 » The Wright brothers pilot the Wright Flyer III in a new world record flight of 24 miles in 39 minutes.
November 18 » Prince Carl of Denmark becomes King Haakon VII of Norway.
November 21 » Albert Einstein's paper that leads to the mass–energy equivalence formula, E=mc², is published in the journal Annalen der Physik.
Day of marriage March 29, 1930
The temperature on March 29, 1930 was between 4.5 °C and 12.4 °C and averaged 8.5 °C. There was 0.5 mm of rain during 0.7 hours. There was 3.6 hours of sunshine (28%). The average windspeed was 4 Bft (moderate breeze) and was prevailing from the southwest. 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.
February 18 » While studying photographs taken in January, Clyde Tombaugh discovers Pluto.
May 27 » The 1,046 feet (319m) Chrysler Building in New York City, the tallest man-made structure at the time, opens to the public.
August 7 » The last confirmed lynching of blacks in the Northern United States occurs in Marion, Indiana; two men, Thomas Shipp and Abram Smith, are killed.
August 29 » The last 36 remaining inhabitants of St Kilda are voluntarily evacuated to other parts of Scotland.
September 8 » 3M begins marketing Scotch transparent tape.
October 3 » The German Socialist Labour Party in Poland – Left is founded.
When copying data from this family tree, please include a reference to the origin: Nienke Oudbier, "Descendants van de Vlag1", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-oudbier/I3670.php : accessed February 7, 2026), "Jan Willem Potkamp (1905-)".
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