Beach Policeman, Potomac River, 1922. (Photo by National Photo Company/Colorized by Patty Allison)

A sheep dressed in a jersey in the colors of the Colombian national soccer team is seen during a exhibition in Nobsa, Colombia June 1, 2014. The sheep is named Falcao, after the Colombian player. REUTERS/Jose Miguel Gomez

This undated photo shows the Arctic National Wildlife Refuge in Alaska. (Photo by U.S. Fish and Wildlife Service/Getty Images)

Tianmen Mountain is a mountain located within Tianmen Mountain National Park, Zhangjiajie, in northwestern Hunan Province, China.

HRP-4C, a five-foot humanoid robot developed at Japan's National Institute of Advanced Industrial Science and Technology, sings and dances with performers at the Digital Contents Expo in Tokyo on October 17, 2010. The robot runs entertainment software called Choreonoid, a name formed from the words “choreograph” and “humanoid”. (Yoshikazu Tsuno/AFP)

Passengers watch as The Waverley, the world's last remaining seagoing passenger paddle steamer arrives at Clevedon Pier on June 10, 2011 in Clevedon, England. Built in 1946, the trust which owns and operates the Waverley, is warning that this could be the last season for the vessel and is appealling for more public funding saying it is struggling to make ends meet in the current financial climate due in part to rising fuel costs. Restored in 1973 after service on Loch Long in Scotland, since 2003, Waverley has been listed in the British National Register of Historic Ships core collection as 'a vessel of pre-eminent national importance'. (Photo by Matt Cardy/Getty Images)

A Fulton Hotshot lights a controlled burn on the so-called “Rough Fire” in the Sequoia National Forest, California, August 21, 2015. In California, suffering its worst drought on record, about 2,500 people were forced to flee Christian camps east of Fresno at Hume Lake as the so-called Rough Fire crossed Highway 180, officials said. (Photo by Max Whittaker/Reuters)