A British woman plays a piano designed especially for people who are confined to bed. Date: 1935. (Photo by Mary Evans Picture Library/Caters News)

A new monorail service in Houston, Texas, ready for its inaugural service. (Photo by Evans/Three Lions/Getty Images). Circa 1950

“In anatomy, heterochromia refers to a difference in coloration, usually of the iris (but also of hair or skin). Although infrequently seen in humans, complete heterochromia is more frequently observed in other species, where it almost always involves one blue eye”. – Wikipedia (Photo by StooMathiesen)

This picture taken on January 12, 2014 shows pet dogs, a yellow duck and a chicken in a skiing resort for a skiing competition in Sanmenxia, north China's Henan province. A tortoise beat a rabbit in a skiing competition held for pets and their owners in northern China, a report said on January 14. Cats and dogs faced off against a menagerie including a rooster and a yellow duck in a race to the finish line on snowy slopes in China's Hebei province, the state-run China News Service said. (Photo by AFP Photo)

A dog dives during a pet dog swimming contest at the Taoyuan Pet Center on July 31, 2005 in Chengdu of Sichuan Province, southwest China. Over 30 dogs have attended the match. According to state media, with the country's pet population growing fast, analysts predict that the market potential for the “pet economy” in China could reach a minimum of RMB 15 billion (about USD 1.85 billion). (Photo by China Photos/Getty Images)

Georgie Bain takes a selfie with her horse in “Best Friends” in Aberdeen, United Kingdom, Date Unknown. For the first time, the founders of the Comedy Wildlife Photography Awards have launched a photography award show giving proud pet owners a chance to show off their quirky pets. (Photo by Georgie Bain/Barcroft Images/Comedy Pet Photography Awards)

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