Erica Bougard of the U.S. competes in the high jump event of the women's heptathlon during the 15th IAAF World Championships at the National Stadium in Beijing, China, August 22, 2015. (Photo by Fabrizio Bensch/Reuters)

A pro-Russian rebel guards a captured former Ukrainian Army checkpoint outside Vuhlehirsk, Donetsk region, eastern Ukraine, Thursday, February 5, 2015. The rebels have closed in around the town in a strategy they triumphantly refer to as the Debaltseve cauldron. Separatists recently burst through government lines in the rural settlement of Vuhlehirsk. (Photo by Vadim Braydov/AP Photo)

At the beginning of the 20th century, Edward S. Curtis set out to document what he saw as a disappearing race: the Native American. From 1907 to 1930, Curtis took more than 2,000 photos of 80 tribes stretching from the Great Plains to the Pacific Northwest and Alaska. He then published and sold these photos, along with narrative text, in 20 volumes of work known as “The North American Indian”. It is one of the most significant collections of its kind, “probably the most important photographic document of its age and its topic,” said Jeffrey Garrett, associate university librarian for Special Libraries at Northwestern University. (Photo by Edward S. Curtis)

A woman doing yoga at a fountain, in downtown Stuttgart, Germany, Thursday, June 22, 2017. Weather forecasts predict hot summer weather as well as thunderstorms for some parts of Germany. (Photo by Marijan Murat/DPA via AP Photo)

Street musicians with their faces covered with animal masks play to earn some money in central Vienna, Austria, November 8, 2015. (Photo by Vasily Fedosenko/Reuters)

The civilised world lies on its knees, a sickness wracking its body. The affliction causes a necrotising of tissues so perfectly uniform in distribution that victims take on the appearance of corpses long before death occurs due to organ failure or secondary infections. ...

Bikini-clad women ski as they are led by a car during a performance on the frozen Yenisei River outside Krasnoyarsk, Siberia, Russia, March 20, 2016. The performance, entitled “Siberian Spring's Strings” and created with the participation of artist Vasily Slonov, marked the day of spring equinox (vernal equinox), according to organizers. (Photo by Ilya Naymushin/Reuters)

A street performer dressed up as a waiter performs for at Marques de Larios street in downtown Malaga, Spain, July 4, 2016. (Photo by Jon Nazca/Reuters)