John Gourley leans out of the cab of Goliath, one of Europe's largest cranes on September 20, 2011 in Rosyth, Scotland. The crane will begin the assembly of the Queen Elizabeth Class aircraft carriers later this week, when it lifts the first section of the two deck high 8,000 tonne centre block, which includes a section of the flight deck. The lift will mark the start of the Rosyth shipyards assembly of the first of two 65,000 tonne vessels the largest warships ever built for the Royal Navy. (Photo by Jeff J Mitchell/Getty Images)

Charlotte Roirdan from Lyon & Turnbull views a letter written by Mary Queen of Scots on March 8, 2012 in Edinburgh, Scotland. The 450 year old letter, unearthed in Blair Castle in Ayrshire, has been verified as the hand writing of Mary Queen of Scotts and has been valued at 3,000 GBP. The letter, dated March 20, 1554, relieves the then laird of Blair from his duties due to gout and will be put up for sale next week at an auction in Edinburgh. (Photo by Jeff J. Mitchell/Getty Images)

An army tank fires during a firefight against militants linked to al Qaeda near the southern Yemeni city of Zinjibar May 30, 2012. (Photo by Reuters/Yemen's Defence Ministry)

Members of an American landing party assist troops whose landing craft was sunk by enemy fire off Omaha beach, near Colleville sur Mer, France, June 6, 1944. REUTERS/Weintraub/US National Archives

“A prototype lunar lander was destroyed on August 9, 2012, at Kennedy Space Center during its first free flight”. – James Dean via Florida Today

Photo: Morpheus Ground Level Hot Fire. Photo Date: April 2nd 2012. Location: VTB Flight Complex; Photographer: Joe Bibby

Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)

A woman attempts to cover a tear gas canister fired by police at a crowd in Srinagar protesting against the recent killings in Kashmir, August 17, 2016. (Photo by Cathal McNaughton/Reuters)

Riot police fire tear gas during a protest by supporters of Dilma Rousseff in Sao Paulo, Brazil August 31, 2016. (Photo by Paulo Whitaker/Reuters)