Dr. P.A. Smithe was sent by the American Red Cross as a doctor and surgeon to work at a hospital in Vienna. He sailed to Europe in December 1915 and returned home in August 1916, according to his daughter, who donated his images to the National World War I Museum. Photo: Turkish army, including cavalry, infantry and artillery. (Photo by Dr. P.A. Smithe/National World War I Museum, Kansas City, Mo.)

A Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

Three Chinese soldiers at the time of a civil war in China. (Photo by General Photographic Agency/Getty Images). 1922

Students from Glasgow Art School modelling casual clothing and Buchan tartan in the annual Fashion Show for charities. During Rag Week students parade in the city streets wearing costumes designed and made by themselves. (Photo by Haywood Magee/Picture Post/Getty Images). 7th February 1953

A woman lays in a puddle of tomato juice during the annual “Tomatina” tomato fight fiesta in the village of Bunol, 50 kilometers outside Valencia, Spain, Wednesday, August 27, 2014. The streets of an eastern Spanish town are awash with red pulp as thousands of people pelt each other with tomatoes in the annual “Tomatina” battle that has become a major tourist attraction. At the annual fiesta in Bunol on Wednesday, trucks dumped 125 tons of ripe tomatoes for some 22,000 participants, many from abroad to throw during the hour-long morning festivities. (Photo by Alberto Saiz/AP Photo)

Spectators dressed as leprechauns attend St Patrick's Day parade in Dublin on March 17, 2014. (Photo by Peter Muhly/AFP Photo)

First prize. Taken over Bali Barat National Park, Denpasar, Bali. Made with a GoPro Hero 2 camera. (Photo by Capungaero)

An indigenous woman participates in a parade called "International Indigenous Beauty" during the first World Games for Indigenous Peoples in Palmas, Brazil, October 24, 2015. Billed as the indigenous Olympics, the games are expected to attract nearly 2,000 athletes from dozens of Brazilian ethnicities, as well as from such far-flung nations as Ethiopia and New Zealand. (Photo by Ueslei Marcelino/Reuters)