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 Viet Cong suspect holds his hands up after a Vietnamese Ranger from the 21st Vietnam Infantry Division routed him from his hiding place. (Photo by Keystone/Getty Images). 7th November 1967

Heralds ride on horse-back through the streets of Moscow proclaiming the forthcoming coronation of Tsar Nicholas II, 1896. P.S. All pictures are presented in high resolution.

A participant of the sled dogs race in action with the dogs in Stroehen (Lower Saxony), Germany, 18 October 2015. It is the first round of the North German Championship. (Photo by Peter Steffen/EPA)

A masked man in military fatigues brings a blindfolded Irma Krat, arrested and held by pro-Russian protestors before her meeting with journalists near of occupied police station in Slaviansk, Ukraine, 21 April 2014. Pro-Russian activists are demanding broader autonomy from Kiev and closer ties to Russia. Pro-Russian activists continued occupying government, police and other administrative buildings in eastern Ukrainian cities, in defiance of an ultimatum by the Ukrainian government to lay down their weapons. Russia, the United States, the European Union and Ukraine on 17 April had agreed on steps to de-escalate the crisis in Ukraine during talks in Geneva, Switzerland. (Photo by Roman Pilipey/EPA)

A boy looks inside the skull of a Tyrannosaurus Rex replica at the Egidio Feruglio Museum in Trelew, Argentina, in this May 18, 2014 file photograph. Scientists on July 28, 2015 unveiled a comprehensive analysis of the teeth of the group of carnivorous dinosaurs called theropods, which include the Tyrannosaurus Rex, detailing a unique serrated structure that let them chomp efficiently through the flesh and bones of large prey. (Photo by Maxi Jonas/Reuters)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)