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.)

South Korean teenagers participate in a warfare exercise as part of the Special Warfare Command's training course at a military base on August 4, 2011 in Seoul, South Korea. About 1,000 civilian volunteers including middle and high school students participated in the special force's four-day training programme to develop their spiritual and physical strength. (Photo by Chung Sung-Jun/Getty Images)

Bus 392 stands on the highway running from Beersheva to Eilat, with windows broken following a gun attack on August 18, 2011 near the Israel - Egypt border, Israel. A series of coordinated gun and roadside bomb attacks against miltary and civilian targets near the Israeli - Egyptian border, including an ambush on the bus travellling 20km north of Eilat, are reported to have left 5 dead and many injured. (Photo by Yehuada Ben Itah/Getty Images)

Children watch a rabbit, jumping over a hurdle at an obstacle course the 5th Open Rabbit Sport Tournament (5. offene Kaninchensport Turnier) on August 28, 2011 in Rommerz near Fulda, Germany. Eighty rabbits competed in light-weight, middle-weight and jumping-for-points categories at today's tournament in Rommerz that is based on Kanin Hop, or Rabbit Hopping. Rabbit Hopping is a growing trend among pet rabbit owners in Central Europe and the first European Championships are scheduled to be held later this year in Switzerland. (Photo by Ralph Orlowski/Getty Images)

A Hindu villager rides a motorcycle past an altar ahead of the annual Kasada festival at the Mount Bromo in Indonesia's East Java province, July 30, 2015. The Kasada festival will be held on August 1, when the worshippers throw offerings such as livestock and other crops into the volcanic crater of Mount Bromo to give thanks to the Hindu gods for ensuring their safety and prosperity. (Photo by Reuters/Beawiharta)

Visitors play in front of hot air balloons during the 2016 International Hot Air Balloon Festival in Taitung, southeast of Taiwan, 01 July 2016. Thirty-one hot-air balloon teams from 14 countries join the six days of competition during the festival, which will run from 01 July to 07 August 2016. (Photo by Ritchie B. Tongo/EPA)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

An elephant from Earl's Court Circus with a man in its mouth, 1928. P.S. All pictures are presented in high resolution.