1) The document presents several historical photographs taken in the 1930s depicting workers during the construction of skyscrapers in New York City between 1920-1935.
2) The first photo is titled "Lunch atop a Skyscraper" and was taken by photographer Charles Ebbets on September 29, 1932 on the 69th floor of the GE Building in Rockefeller Center.
3) Many of the photos are part of the Bettmann collection, one of the largest historical photo collections containing over 11 million images, now owned by Corbis and Bill Gates.