The new EVR system which allows the recording of television programmes which can then be watched at the owner's discretion. The new Teleplayer has been produced in partnership with Rank Bush Murphy Ltd and EVR and has enormous potential. 21st September 1970. (Photo by Central Press/Getty Images)

In this May 4, 2014 photo, a miner holds an amalgam of mercury and gold he mined after working a 28-hour shift at an illegal gold mining process, in La Pampa, in Peru's Madre de Dios region. Thousands of artisanal gold miners sweat through the long shifts and endure, for a few grams of gold, the perils of collapsing earth, limb-crushing machinery and the toxic mercury used to bind gold flecks. (Photo by Rodrigo Abd/AP Photo)

United States Coast Guard Academy Cadets Second Class Aurimas Juodka, left, and Sheila Bertrand get in the face of “swab” Kevin Lennox as Bravo Company finishes at the barber shop and mailroom during R-Day, the reporting-in day that marks the beginning of the 7-week “Swab Summer” for the class of 2018 Monday, June 30, 2014, in New London, Conn. About 250 prospective cadets, Swabs, start the program designed to indoctrinate them to the military life of the academy and at the end will be accepted into the corps of cadets. (Photo by Sean D. Elliot/AP Photo/The Day)

An actor plays an injured passer-by during Exercise Strong Tower, the scene of a mock terror attack at a disused underground station in central London, Britain June 30, 2015. London police held their biggest-ever terrorism drill on Tuesday, pitting the emergency services against a group of marauding attackers, nearly 10 years since four young British Islamists killed 52 people in suicide bombings on London's transport network in July 2005. (Photo by Peter Nicholls/Reuters)

Bottlenose dolphins swim over visitors in water tank at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, southwest of Tokyo, Tuesday, July 21, 2015. Temperatures in Tokyo's metropolitan area neared around 96 degree Fahrenheit, or 35 degree Celsius, on Tuesday. (Photo by Shuji Kajiyama/AP Photo)

A man takes a photo of a radio antenna that's part of the Atacama Large Milimeter Array Observatory on March 12, 2013 at Llano de Chajnantor, about 43 miles (70 kilometers) from San Pedro de Atacama, Chile. The $1.5 billion ALMA facility, which had its official inauguration on March 13, is considered the world's most expensive ground-based observatory. (Photo by Felipe Trueba/EPA)

Naki'o, a mixed-breed dog with four prosthetic devices, goes for a run in Colorado Springs April 12, 2013. Naki'o lost all four feet to frostbite when he was abandoned as a puppy in a foreclosed home. (Photo by Rick Wilking/Reuters)

A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)