Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

Soldiers, including two recruits who have brought some chickens, at Victoria prepare to board the train for the battle front. (Photo by Hulton Archive/Getty Images)

Two friends take a quick selfie during the Grand National Festival at Aintree Racecourse on April 6, 2017 in Liverpool, England. (Photo by WENN)

The lead singer of one band talks to two bemused kids at a gig at the “Warzone Centre” in Belfast, Northern Ireland, 1980s. (Photo by Ricky Adam/Mediadrumworld)

Two young women embrace in bed together, both wearing white lace underwear. (Photo by Popperfoto/Getty Images)

Two cocks are trained for a fight in a village in Nakhon Sawan province, Thailand January 10, 2017. (Photo by Chaiwat Subprasom/Reuters)

A woman surveys the damage after the earthquake on March 17, 2011 in Kensennuma, Japan. (Photo by Chris McGrath/Getty Images)

Backdropped by a night time view of the Earth and the starry sky, the Space Shuttle Endeavour is seen docked to the International Space Station on May 28, 2011. (Photo by Reuters/NASA)