A demonstration on March 15, 1922 on Palace Roof, 57th Street and 7th Avenue, showing the shellproof steel jacket. Leo Krause wearing the jacket, which weighs 12 pounds. Shots used, 38 and 45 calibre, at close range. (Photo by Bettmann Archive)

National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

Hungarians witness the fallen statue of communist leader Josef Stalin in front of the National Theater in Budapest on October 24, 1956. Demonstrators revolting against communist rule in Hungary pulled the statue to the ground at Dozsa Gyorgy on Oct. 23 and hauled it by tractor to Blaha Lujza where it was later smashed to pieces by the people. (Photo by Arpad Hazafi/AP Photo)

A young protester takes part in a protest near Tahrir Square to call for the fall of Islamist President on January 24, 2012 in Cairo. (Photo by Mohammed Abed/AFP Photo via The Atlantic)

An Egyptian actress working at the Pharaonic Village simulates ancient agriculture scenes during a show marking Sham el-Nessim, or “smelling the breeze”, in Giza, Egypt, Monday, April 13, 2015. The holiday signifies the arrival of Spring, a uniquely Egyptian tradition practiced since the days of the Pharaohs. (Photo by Amr Nabil/AP Photo)

The Burney, a new streamlined car on the London streets, designed by Sir Denniston Burney who was responsible for the design of the R100 (R 100) airship. The engine is in the rear. (Photo by Topical Press Agency/Getty Images). 15th September 1930

Children feeding the birds in this Victorian Christmas greetings card. (Photo by Hulton Archive/Getty Images). Circa 1885

In this October 6, 1976, file photo, a right-wing student, center foreground, draws his arm back to strike a captured and wounded leftist student being taken by police to an ambulance in during a student massacre in Bangkok, Thailand. This year’s anti-government protests are seeking new elections, a more democratic constitution and an end to intimidation of political activists. Their speeches have repeatedly highlighted the 1976 tragedy, piquing the interest of the current generation in what their forebears faced. (Photo by Neal Ulevich/AP Photo/File)