A new monorail service in Houston, Texas, ready for its inaugural service. (Photo by Evans/Three Lions/Getty Images). Circa 1950

Two dummy tanks being pushed along a road by German soldiers. (Photo by Hulton Archive/Getty Images). Circa 1925

Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

Afghan paraglider Leeda Ozori, 21, walks after practicing in Kabul, Afghanistan September 14, 2015. She is one of a group of young Afghans taking to the skies of a capital where military helicopters and surveillance balloons are a far more familiar sight. Women in Afghanistan's conservative Muslim society are increasingly entering areas such as education, sports and the workplace, but most still wear the head-to-toe garment, the burqa. (Photo by Mohammad Ismail/Reuters)

Sultan, a famous captive fennec that is displayed tied on a rope in front of a tourist shop, is the main attraction in the souk of Douz, a desert town in Tunisia. By the display of such a charismatic animal, tourists are often lured to buy things or pay for pictures. On inquiry, although Sultan has been caught as a pup in the wild, the owners of the shop reassure the foreigners stating that the animal is ‘domestic’. (Photo by Bruno D’Amicis/Fritz Pölking Prize/GDT EWPY 2015)

A biker poses on his Bousouzoku motorbike at the Dangouzaka rest stop in Yamanashi, west of Tokyo, Japan, January 3, 2016. Police on Sunday halted a group of about two dozen Bousouzoku bikers who paraded their noisy motorcycles during an annual New Year outing in the Mount Fuji region. This Japanese motorcycle subculture dated back to the 1950s and regularly chafes with the police because of their provocative traffic behaviour and bike customising, that is often deemed illegal. (Photo by Thomas Peter/Reuters)

A pet owner holds his guinea pig named Riec as Father Francisco bestows a blessing on the pet rodent during a feast day Mass in honor of Saint Anthony, the patron saint of animals, at the Saint Fernando church, in Mexico City, Saturday, January 17, 2015. Many people in Mexico bring their pets to churches to be blessed by the priest on this day. (Photo by Marco Ugarte/AP Photo)

Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)