A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Two children jumping through a water hydrant's shower on a New York street. They have come from a neighbouring co-educational playgroup organised by the city's Police Department. (Photo by Orlando/Getty Images). 1950

A baby bush-baby in a set of scales at London Zoo shortly after birth. (Photo by Fox Photos/Getty Images). 10th August 1938

A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

A driver on the Horseshoe Pass in North Wales wiping the snow from the windscreen of his car during a heavy snow storm, 18th January 1937. (Photo by Norman Smith)

A steam traction engine with a broken rear axle in Pall Mall, London. (Photo by Topical Press Agency/Getty Images). November 1923

Hasty Pudding Theatricals Woman of the Year Sandra Bullock gets kisses from Vice President John Blickstead (L) and President of Hasty Pudding Theatricals Clare Putnam (C) in Harvard Square February 12, 2004 in Cambridge, Massachusetts. (Photo By Douglas McFadd/Getty Images)

Turkana boys play with rifles in a village inside the Turkana region of the Ilemi Triangle, northwest Kenya December 21, 2014. The Ilemi Triangle is a disputed region in East Africa, claimed by South Sudan and Kenya, bordering also Ethiopia. The dispute arose from unclear wording of a 1914 treaty which tried to allow free movement of the Turkana people, nomadic herders who had traditionally grazed the area. (Photo by Goran Tomasevic/Reuters)