Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

Clown/comedian/filmmaker Pierre Etaix attends The Academy Of Motion Picture Arts And Sciences' Presents “Pierre Etaix: The Laughter Returns” at AMPAS Samuel Goldwyn Theater on November 16, 2011 in Beverly Hills, California. (Photo by Valerie Macon/Getty Images)

Team McLaren Mercedes drivers Lewis Hamilton (L) and Jenson Button unveil the new MP-27 Formula 1 car at the McLaren technology centre on February 1, 2012 in Woking, England. (Photo by Mark Thompson/Getty Images)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

Developed for the British American Ambulance Corps, this new motorcycle ambulance is capable of speeding wounded soldiers 90 miles an hour from the front lines to field hospitals. Its springs are synchronized with the patient's heartbeat to avoid increasing fever when traveling over various Terrain. Viewing it in New York August 27, 1941, are left to right: constable Herbert Scott of England, driver; William E. Detlor, whose firm developed the vehicle; M. W. Stand, inspector-general of Civilian Defense, and Maj. Edward Riekert, also. (Photo by AP Photo)

An Afghan street vendor carries bread on his head ahead of the upcoming holy fasting month of Ramadan in Kabul, Afghanistan, Sunday, June 5, 2016. Muslims across the world will be observing the holy fasting month of Ramadan, when they refrain from eating, drinking and smoking from dawn to dusk. (Photo by Rahmat Gul/AP Photo)

A motorcycle carrying protesters holding a placard using the acronym of the national electoral commission, drives ahead of demonstrators on foot calling for the disbandment of the commission over allegations of bias and corruption, in downtown Nairobi, Kenya Monday, June 6, 2016. (Photo by Ben Curtis/AP Photo)

Workers reinforce the electric pylons at a flooded area as Typhoon Nepartak approaches in Xuancheng, Anhui Province, China, July 9, 2016. (Photo by Reuters/Stringer)