National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

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

An American family with a carved pumpkin illuminated by a candle to celebrate Halloween. (Photo by Sherman/Three Lions/Getty Images). Circa 1955

Photographer Frank Relle takes long-exposure images of houses in New Orleans. Says Relle, “The city at night comes alive for me. I imagine stories about the people’s lives inside the homes based on the evidence on the outside. My photographs become a portrait without the person. The night obscures details and the lack of information gives possibility”. Photo: “Telemachus”. Farragut Street, New Orleans, La. Nov. 2006. (Photo by Frank Relle)

A pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

Australian comedian Barry Humphries, dressed as his most famous character Dame Edna Everage, modelling a stunning Ascot hat based on the Sydney Opera House on June 15, 1976. (Photo by Wesley/Getty Images)

Takeoka Chisaka, Hiroshima, Japan. “One morning in August 1945, I was walking home from the night shift at a factory in Hiroshima. As I reached my door, there was a huge explosion. When I came to, my head was bleeding and I had been blasted 30m away. The atomic bomb had detonated. When I found my mother, her eyes were badly burned. A doctor said they had to come out, but he didn’t have the proper tools so used a knife instead. It was hellish. I became a peace-worker after the war. In the 1960s, at a meeting at the UN, I met one of the people who created the atomic bomb. He apologised”. (Photo and caption by Sasha Maslov)

Two Tibetan women wearing traditional striped aprons, elaborate headdresses and abundant jewellery. Original Publication: From a photograph by Shephard. (Photo by Hulton Archive/Getty Images). Circa 1910