Births on March 4

Oscar Chisini, Italian mathematician and statistician (d. 1967)

Oscar Chisini (March 14, 1889 – April 10, 1967) was an Italian mathematician. He introduced the Chisini mean in 1929.

8 Jan

Punched card
Herman Hollerith is issued US patent #395,791 for the 'Art of Applying Statistics' — his punched card calculator.
30 Jan

Mayerling Incident
Archduke Crown Prince Rudolf of Austria, heir to the Austro-Hungarian crown, is found dead with his mistress Baroness Mary Vetsera in the Mayerling.
23 Mar

Mirza Ghulam Ahmad
The Ahmadiyya Muslim Community is established by Mirza Ghulam Ahmad in Qadian, British India.
2 May

Treaty of Wuchale
Menelik II, Emperor of Ethiopia, signs the Treaty of Wuchale, giving Italy control over Eritrea.
6 May

Exposition Universelle (1889)
The Eiffel Tower is officially opened to the public at the Universal Exposition in Paris.