The call system, by which Members could call for a Page to carry messages or fetch documents, was an important tool in the modern House Page’s work. This card provided a guide to decoding call signals. Members pressed buttons that lit up a switchboard in the back of the House Chamber, where Pages sat waiting to run errands. The most important numbers were at the top, and the remainder laid out in a complicated pattern reflected in the card's layout.
History, Art & Archives, U.S. House of Representatives, “Page Call System Card,” https://history.house.gov/Collection/Listing/2002/2002-023-001/ (September 25, 2022)
Office of the Historian
Office of Art and Archives
Attic, Thomas Jefferson Building
Washington, D.C. 20515