Egyptian bootblacks cleaning a European's shoes in Cairo. (Photo by Hulton Archive/Getty Images). Circa 1870

A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

A Mark IV tank, part of the parade at the Lord Mayor's Show in London. (Photo by Topical Press Agency/Getty Images). November 1917

A workman takes a siesta on a girder during the building of Radio City, the city of New York spread out below. (Photo by General Photographic Agency/Getty Images). Circa 1933

The Verreauxs Sifaka, otherwise known as Dancing Sifaka, who was caught strutting its stuff in Madagascar, has definitely learnt a lesson or two from King Julian – from the 2005 film “Madagascar”. Raising both of its arms and lunging from side to side, this lemur definitely likes to move it, move it. (Photo by Shannon Wild/Caters News Agency)

Four-year-old Chinese boy Huang Yang plays with five-year-old beluga whale Xiao Xin at the Qingdao Ocean World on November 3, 2007 in Qingdao of Shandong Province, China. Huang Yang began swimming as a baby and fell in love with the whale after watching its performance. On the International Children's Day, June 1 this year, the Qingdao Ocean World has made the boy's dream come true when they allowed Huang Yang to swim with the beluga whale. (Photo by China Photos/Getty Images)

Edward, Prince of Wales (1840–1910), later King Edward VII, stands over the carcass of a wild Chillingham bull, shot by himself during a visit to Chillingham Castle, Northumberland, circa 1879. (Photo by Hulton Archive/Getty Images)

A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)