The temperature on January 4, 1889 was about -3.0 °C. The air pressure was 4 kgf/m2 and came mainly from the east. The airpressure was 78 cm mercury. The atmospheric humidity was 94%. Source: KNMI
January 8 » Herman Hollerith is issued US patent #395,791 for the 'Art of Applying Statistics' — his punched card calculator.
January 22 » Columbia Phonograph is formed in Washington, D.C.
January 30 » Archduke Crown Prince Rudolf of Austria, heir to the Austro-Hungarian crown, is found dead with his mistress Baroness Mary Vetsera in the Mayerling.
July 11 » Tijuana, Mexico, is founded.
August 4 » The Great Fire of Spokane, Washington destroys some 32 blocks of the city, prompting a mass rebuilding project.
November 8 » Montana is admitted as the 41st U.S. state.
Day of marriage November 19, 1910
The temperature on November 19, 1910 was between -2.4 °C and 6.9 °C and averaged 2.2 °C. There was 0.1 mm of rain. There was 4.5 hours of sunshine (52%). The average windspeed was 2 Bft (weak wind) and was prevailing from the northwest. Source: KNMI
When copying data from this family tree, please include a reference to the origin: Gert Pieters, "Family tree Koops", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-koops/I997.php : accessed January 14, 2026), "Roelofje de Boer (1889-????)".
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