A fireman from the London Fire Brigade, wearing a smoke helmet. (Photo by Topical Press Agency/Getty Images). Circa 1908

A workman takes a siesta on a girder during the building of Radio City, the city of New York spread out below. (Photo by General Photographic Agency/Getty Images). Circa 1933

A rail worker fixing a fog warning notice at South Woodford Railway Station in Essex. (Photo by H. F. Davis/Topical Press Agency/Getty Images). 20th October 1938

A spotless GWR (Great Western Railway) locomotive, the “Royal Sovereign” waiting to carry Queen Victoria's coffin. (Photo by Hulton Archive/Getty Images). 28th January 1901

Troops of the Interior Ministry take part in a parade during a ceremony marking the Iraqi Police Day at a police academy in Baghdad January 9, 2016. (Photo by Khalid al Mousily/Reuters)

A Palestinian throws snow at his wife during a snow storm in West Bank old city of Hebron, January 26, 2016. (Photo by Mussa Qawasma/Reuters)

This picture released by Turkish Cumhuriyet Daily newspaper shows Dilek Dundar (L), the wife of editor-in-chief of Turkish newspaper Cumhuriyet daily Can Dundar, trying to stop a gunman who is also being held back by a man on May 6, 2016 in Istanbul. Turkish opposition journalist Can Dundar escaped a shooting on May 5 outside a courthouse in Istanbul where he is on trial, adding police detained the assailant. Dundar, who was unharmed, was outside the courthouse during a break as the court prepared to deliver its verdict in his trial for allegedly revealing state secrets in a newspaper story. (Photo by AFP Photo/Cumhuriyet Daily Newspaper)

Employees of the Park Royal resort wait for a shuttle to take them to work early in the morning on April 2, 2015 in Acapulco, Mexico. Despite problems with cartel violence Semana Santa is one of the biggest tourist weeks of the year in Acapulco, a city whose entire economy depends on tourism, and officials expect around 350,000 mostly Mexican visitors this week. (Photo by Jonathan Levinson/The Washington Post)