May 7 » In Saint Petersburg, Russian scientist Alexander Stepanovich Popov demonstrates to the Russian Physical and Chemical Society his invention, the Popov lightning detector—a primitive radio receiver. In some parts of the former Soviet Union the anniversary of this day is celebrated as Radio Day.
June 20 » The Kiel Canal, crossing the base of the Jutland peninsula and the busiest artificial waterway in the world, is officially opened.
June 27 » The inaugural run of the Baltimore and Ohio Railroad's Royal Blue from Washington, D.C., to New York City, the first U.S. passenger train to use electric locomotives.
November 5 » George B. Selden is granted the first U.S. patent for an automobile.
November 8 » While experimenting with electricity, Wilhelm Röntgen discovers the X-ray.
December 28 » The Lumière brothers perform for their first paying audience at the Grand Cafe in Boulevard des Capucines.
Day of marriage March 13, 1930
The temperature on March 13, 1930 was between -0.9 °C and 4.6 °C and averaged 1.5 °C. There was 4.2 mm of rain during 3.2 hours. There was 3.2 hours of sunshine (27%). The average windspeed was 3 Bft (moderate breeze) and was prevailing from the west. 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 6 » International Unemployment Day demonstrations globally initiated by the Comintern.
April 22 » The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.
May 7 » The 7.1 Mw Salmas earthquake shakes northwestern Iran and southeastern Turkey with a maximum Mercalli intensity of IX (Violent). Up to three-thousand people were killed.
October 3 » The German Socialist Labour Party in Poland – Left is founded.
October 5 » British airship R101 crashes in France en route to India on its maiden voyage.
When copying data from this family tree, please include a reference to the origin: W.J. Oving, "Family tree Oving", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-oving/I8530.php : accessed January 2, 2026), "Johan SLOETJES (1895-????)".
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