The temperature on June 9, 1884 was about 14.5 °C. There was 0.9 mm of rain. The air pressure was 1 kgf/m2 and came mainly from the west-southwest. The airpressure was 76 cm mercury. The atmospheric humidity was 78%. Source: KNMI
In The Netherlands , there was from April 23, 1884 to April 21, 1888 the cabinet Heemskerk, with Mr. J. Heemskerk Azn. (conservatief) as prime minister.
February 19 » More than sixty tornadoes strike the Southern United States, one of the largest tornado outbreaks in U.S. history.
April 20 » Pope Leo XIII publishes the encyclical Humanum genus.
May 31 » The arrival at Plymouth of Tāwhiao, King of Maoris, to claim the protection of Queen Victoria.
October 6 » The Naval War College of the United States is founded in Rhode Island.
October 22 » The International Meridian Conference designates the Royal Observatory, Greenwich as the world's prime meridian.
November 1 » The Gaelic Athletic Association is set up in Hayes's Hotel in Thurles, County Tipperary.
Day of marriage May 6, 1911
The temperature on May 6, 1911 was between 2.7 °C and 13.9 °C and averaged 8.6 °C. There was 12.1 hours of sunshine (80%). The average windspeed was 3 Bft (moderate breeze) and was prevailing from the north. Source: KNMI
April 8 » Dutch physicist Heike Kamerlingh Onnes discovers superconductivity.
July 7 » The United States, UK, Japan, and Russia sign the North Pacific Fur Seal Convention of 1911 banning open-water seal hunting, the first international treaty to address wildlife preservation issues.
September 18 » Russian Premier Pyotr Stolypin is shot at the Kiev Opera House.
September 25 » An explosion of badly degraded propellant charges on board the French battleship Liberté detonates the forward ammunition magazines and destroys the ship.
November 17 » Omega Psi Phi fraternity was founded on the campus of Howard University in Washington, D.C.
November 19 » The Doom Bar in Cornwall claimed two ships, Island Maid and Angele, the latter killing the entire crew except the captain.
Day of death December 21, 1931
The temperature on December 21, 1931 was between -1.2 °C and 2.0 °C and averaged 0.4 °C. The average windspeed was 3 Bft (moderate breeze) and was prevailing from the east-northeast. 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 26 » Ho Chi Minh Communist Youth Union is founded in Vietnam.
March 26 » Swissair is founded as the national airline of Switzerland.
May 14 » Five unarmed civilians are killed in the Ådalen shootings, as the Swedish military is called in to deal with protesting workers.
July 1 » United Airlines begins service (as Boeing Air Transport).
December 9 » The Constituent Cortes approves a constitution which establishes the Second Spanish Republic.
December 11 » Statute of Westminster 1931: The British Parliament establishes legislative equality between the UK and the Dominions of the Commonwealth—Australia, Canada, Newfoundland, New Zealand, South Africa, and Ireland.
When copying data from this family tree, please include a reference to the origin: J. Ham, "Family tree Ham", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-ham/I1500.php : accessed March 6, 2026), "Roelf Potze (1884-1931)".
Copy warning
Genealogical publications are copyright protected. Although data is often retrieved from public archives, the searching, interpreting, collecting, selecting and sorting of the data results in a unique product. Copyright protected work may not simply be copied or republished.
Please stick to the following rules
Request permission to copy data or at least inform the author, chances are that the author gives permission, often the contact also leads to more exchange of data.
Do not use this data until you have checked it, preferably at the source (the archives).
State from whom you have copied the data and ideally also his/her original source.