Captain George Ash lies on his back as he prepares to shoot the bowl from the clay pipe held between a blindfolded corporal's teeth. (Photo by Fox Photos/Getty Images). 18th April 1932

“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

Emma Watson poses at the winners boards at the Sony Ericsson Empire Film Awards at the Grosvenor House Hotel on March 9, 2008 in London England. (Photo by Dan Kitwood/Getty Images)

Impala pictured in the Kruger National Park on December 7, 2007 in Mpumalanga, South Africa. (Photo by Warren Little/Getty Images)

7 year old Soni has a basket of coal lifted onto her head by her mother, 28 year old Savita, after having scavenged coal illegally from an open-cast coal mine in the village of Bokapahari on February 08, 2012 near to Jharia, India. (Photo by Daniel Berehulak /Getty Images)

Mary McHugh mourns her slain fiance Sgt. James Regan at “Section 60” of the Arlington National Cemetery May 27, 2007. Regan, a US Army Ranger, was killed by an IED explosion in Iraq. (Photo by John Moore/Getty Images)

Women wearing face-kini masks lie on a beach to rest in Qingdao, Shandong province, China, June 3, 2015. A pale complexion is highly prized as delicate and feminine in China while dark skin suggests tanning caused by farming the fields or other lowly, outdoor work. (Photo by Reuters/Stringer)

People try to board a goverment bus during the second day of a suspension of public transport services in Apopa, El Salvador July 28, 2015. Violent gangs in El Salvador ordered bus drivers to strike on Monday in a conflict that has killed six people and left thousands of commuters stranded on the streets of the Central American capital, police and bus company officials said. (Photo by Jose Cabezas/Reuters)