A man flies a kite made of 110 Tukkal or paper lanterns for the Hindu festival of “Makar Sankranti”, which marks the start of spring, in Ahmedabad January 13, 2011. (Photo by Amit Dave/Reuters)

Prayer flags fly at Namgyal Tsemo Monastery above the town of Leh in Ladakh, India September 24, 2016. High in the Indian Himalayas, young novice monks in maroon robes take their lessons inside the 15th-century Thiksey monastery. (Photo by Cathal McNaughton/Reuters)

A zookeeper feeds a hippopotamus with a watermelon in its enclosure in Belgrade's zoo, Serbia, July 20, 2015. Temperatures in Serbia have risen up to 40 degrees Celsius (104 degrees Fahrenheit), according to official meteorological data. (Photo by Marko Djurica/Reuters)

Apple CEO Tim Cook discusses the new iPhone 6 and iPhone 6 plus on Tuesday, September 9, 2014, in Cupertino, Calif. The iPhone 6 will have a screen measuring 4.7 inches, while the iPhone 6 Plus will be 5.5 inches. (Photo by Marcio Jose Sanchez/AP Photo)

Flash, a golden retriever, plays with a toy following a press event for the American Kennel Club to reveal the nations most popular dog breeds in the Manhattan borough of New York, February 22, 2016. (Photo by Carlo Allegri/Reuters)

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 Muslim bride waits for the start of a mass marriage ceremony in Mumbai, India, January 27, 2016. A total of 12 Muslim couples took their wedding vows during the mass marriage ceremony organised by a Muslim voluntary organisation, organisers said. (Photo by Danish Siddiqui/Reuters)