Revellers react after falling in the mud at Worthy Farm in Somerset during the Glastonbury Festival, Britain, June 26, 2016. (Photo by Stoyan Nenov/Reuters)

A Harley Davidson biker is dressed as Santa Claus as he takes part in a charity ride in Zurich, Switzerland December 6, 2015. (Photo by Arnd Wiegmann/Reuters)

A young Chinese girl dressed in Christmas costume, hugs a pedestrian on a street to celebrate Christmas in Nanjing city, east China's Jiangsu province, 23 December 2015. (Photo by Imaginechina/Splash News)

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)

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