Alan Wilson, Director of James Ritchie & Son clockmakers, founded in 1809, adjusts a clock face at the Cannongate Tobooth to British Summer Time on March 21, 2012 in Edinburgh, Scotland. The Tolbooth, built in 1591, was where tolls and public dues were collected. The clock face dates back to 1820 and replaced an earlier clock from the 17th Century. Clocks will be put forward by one hour on Sunday March 25, 2012 at 1.00am and British Summer Time (BST) will officially start. (Photo by Jeff J. Mitchell/Getty Images)

An environmental activist adjusts his mask while taking part in “The Dead Sea Swim Challenge”, swimming from the Jordanian to Israeli shore, to draw attention to the ecological threats facing the Dead Sea, in Kibbutz Ein Gedi, Israel November 15, 2016. Swimmers from around the world plunged into the salty waters of the Dead Sea on Tuesday to attempt a seven-hour swim across the fabled lake in a bid to draw attention to its environmental degradation. Wearing protective masks and snorkels, 25 swimmers paddled through the muddy water to attempt the 9-mile (15-kilometer) swim from Jordan to Israel. (Photo by Nir Elias/Reuters)

A leopard skin burns as Indian officials and activists burn wildlife contraband including tiger and leopard skins, and bones as part of a campaign to save the tiger in Mumbai, India, Tuesday, July 30, 2013. Despite conservation efforts, tiger numbers in India have declined due to rampant poaching of the cats for their valuable pelts and body parts that are highly prized in traditional Chinese medicine. (Photo by Rafiq Maqbool/AP Photo)

Submersible “Jiaolong” is put into the sea for the second dive during a series of six scheduled ones to attempt the country's deepest-ever 7,000-meter manned dive on June 19, 2012 in At Sea, Unspecified. The submersible “Jiaolong”, carrying three people, reportedly reached a depth of 6,965 meters in the Mariana Trench, the deepest part of the world's oceans which is located in the western Pacific Ocean, on June 19, local time. (Photo by China Foto Press)