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)

Mr. Grindell Matthews with his latest invention, the new photographic gun which is the latest development in sky signs. 1933. It can throw a beam of light 15 miles into the sky. (Photo by Fox Photos)

A biplane taking part in the Vintage Air Rally lands, in Stellenbosch, near Cape Town, South Africa December 16, 2016. (Photo by Mike Hutchings/Reuters)

Municipal workers try to retrieve the lid of a manhole to prevent pedestrians from falling in, in Mumbai, India, Wednesday, September 20, 2017. Incessant rainfall in India's commercial capital has affected air and rail traffic, and schools and colleges remained shut for the day. (Photo by Rafiq Maqbool/AP Photo)

Kashmiri children play with snow on a wooden foot bridge in the interiors of Dal Lake in Srinagar on January 16, 2017. A cold wave has further tightened its grip in Jammu and Kashmir, with most places in the state recording sub-zero temperatures. (Photo by Tauseef Mustafa/AFP Photo)

School children dressed in traditional attire eat breakfast before participating in a Republic day parade in Bangalore, India, Thursday, January 26, 2017. (Photo by Aijaz Rahi/AP Photo)