Street fighting in Berlin between Government troops and Spartacists, during the Spartacist uprising which followed Germany's defeat in World War I. (Photo by Keystone/Getty Images). 1919

The Dynasphere, an electrically-driven wheel, invented by Mr. J. A. Purves of Taunton and his son. It had 2.5 horse power and once attained a speed of 25 mph. (Photo by Fox Photos/Getty Images). 1932

Battle-weary American troops withdraw from Yong San in Korea. (Photo by Keystone/Getty Images). 1950

Sleeping Baby Bunny. A 6 day old baby bunny with mouth open while sleeping =D. Photo by Crezalyn Nerona Uratsuji

A woman adjusts the Mantle of the Order of the British Empire at an exhibition at Buckingham Palace in London, Thursday, July 21, 2016. In celebration of Her Majesty's 90th birthday this year, visitors to the Summer Opening of the State Rooms at Buckingham Palace will enjoy an unprecedented display of The Queen's outfits, from childhood to the present day, in the special exhibition Fashioning a Reign: 90 Years of Style from The Queen's Wardrobe. (Photo by Frank Augstein/AP Photo)

Copies of the Unauthorized Autobiography of Wikileaks founder Julian Assange are on display and on sale in Waterstones bookstore on September 22, 2011in Edinburgh, Scotland. The Wikileaks founder has accused publishers Cannongate of a breach of contract after releasing drafts of his autobiography without his approval. (Photo by Jeff J Mitchell/Getty Images)

A Sotheby's employee holds a 110.03 carat sun-drop diamond on October 24, 2011 in London, England. The diamond is the largest yellow pear-shaped diamond in the world, and is expected to fetch between $11-15 Million USD when it is sold at auction at Sotheby's Auction house in London. (Photo by Dan Kitwood/Getty Images)

The Solar Impulse 2 airplane, flown by test pilot Markus Scherdel, flies off the coast of Oahu during a test flight from Kalaealoa Airfield in Kapolei, Hawaii, March 3, 2016. The solar-powered plane is ready to continue its revolutionary voyage around the world. After the craft was grounded in Hawaii last July due to overheated batteries, it was repaired and upgraded, and a recent initial test flight proved successful. (Photo by Eugene Tanner/Reuters)