January 26, 1905 – The world's largest diamond is found in South Africa

The Cullinan Diamond weighed 3106.75 carats (621.35 g or 1.37 lb) and has an estimated value of 2 billion USD.

January 27, 1983 – The first shaft of the world's longest tunnel is completed

The Seikan Tunnel, 53.85 km (33.46 mi) in length, connects the Japanese islands of Honshu and Hokkaido.

January 28, 1820 – Fabian von Bellinghausen discovers the Antarctic

The Baltic German explorer is believed to be the first person to see the Earth’s southernmost continent.

January 29, 1886 – German engineer Carl Benz patents the first modern automobile

His “Benz Patent-Motorwagen Nummer 1” was the first gasoline-driven car.

January 30, 1933 – Adolf Hitler becomes Chancellor of Germany

The “Machtergreifung” marked the end of the Weimar Republic and the beginning of the “Third Reich”. 

January 31, 2010 – Alaska Airlines flight 261 crashes into the sea

The MD-83 experienced horizontal stabiliser problems before descending into the Pacific Ocean, killing all 88 on board.

February 1, 1884 – The first fascicle of the “Oxford English Dictionary” is published. 

The book contained entries A to Ant.