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.)

In northwest Russia, in a small village called Alekhovshchina, Nadia Sablin's aunts spend the warmer months together in the family home and live as the family has always lived, chopping wood to heat the house and making their own clothes. Sablin's book of photographs, “Aunties: The Seven Summers of Alevtina and Ludmila”, is published by Duke University Press. Here: “Two-Handed Saw, 2014”. (Photo by Nadia Sablin)

Looking towards the Times Building on Times Square, the Paramount Building is on the right, and Seventh Avenue on the left crossing Broadway. (Photo by General Photographic Agency/Getty Images). Circa 1930

The Lumix GX1 single lens reflex (SLR) camera with 14-42 mm powerzoom lens is displayed at the Panasonic booth at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 10, 2012 in Las Vegas, Nevada. The new camera comes with an external viewfinder and flash and an ISO up to 12,800. The camera as shown sells for USD 949; the camera body alone is USD 799. (Photo by Ethan Miller/Getty Images)

A recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)

“Boom, a three-year-old Staffordshire Bull Terrier, who loves birds and rabbits. He has already acquired a legion of fans on his Facebook page, and who can blame them? He might actually be the cutest pup we've ever laid eyes on (and his little buddies seem to agree). Check out these pics and see if you don't fall in love!” (Photo by Boom)

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

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