People visit Chinese artist Huang Yongping's installation art work named “Leviathanation” at Tang Contemporary Art of 798 Art District on March 29, 2011 in Beijing, China. The exhibition named “Tracing The Milky Way” will be last until May 14. (Photo by Feng Li/Getty Images)

A garbage collector, with his horse and cart, prepares to unload rubbish at the municipal dump in Nezahualcoyotl, on the outskirts of Mexico City, February 18, 2015. Hundreds of horse or donkey-drawn carts will disappear from the streets of a municipality in the state of Mexico, located on the outskirts of Mexico City, and will be replaced by motorized vehicles, local authorities said. (Photo by Henry Romero/Reuters)

Revellers try to hold on to a wild horse during the “Rapa das Bestas” traditional event in the village of Sabucedo, northwestern Spain, July 5, 2015. On the first weekend of the month of July, hundreds of wild horses are rounded up, trimmed and groomed in different villages in the Spanish northwestern region of Galicia. (Photo by Miguel Vidal/Reuters)

A couple who did not give their names walk in downtown Havana, February 2, 2015. (Photo by Alexandre Meneghini/Reuters)

In this Thursday, August 17, 2017 photo, a troupe charges and fires their rifles during Tabourida, a traditional horse riding show also known as Fantasia, in Mansouria, near Casablanca, Morocco. Thousands gathered recently in Mansouria, a small town south of the capital Rabat, to attend one of the oldest festivals in Morocco. Nineteen horse troupes came from different parts of the kingdom to celebrate a three-day event that blends courage, skill and tradition. (Photo by Mosa'ab Elshamy/AP Photo)

Two drunk race-goers make their way home after the last race of the third day of the Royal Ascot horse racing week June 19, 2003 in Ascot, England. (Photo by Scott Barbour/Getty Images)

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

A musician from the Rajan Band, Kotla Mubarakpur holds on to a decorated horse as he and others wait prior to performing at a wedding on November 22, 2011 in New Delhi, India. (Photo by Daniel Berehulak/Getty Images)