A Sector clock or colour change clock was a round colour-coded clock used at military airfields and observation posts in the United Kingdom to help track the movements of enemy aircraft and control friendly aircraft.
Famous quotes containing the word clock:
““Pop” Wyman ruled here with a firm but gentle hand; no drunken man was ever served at the bar; no married man was allowed to play at the tables; across the face of the large clock was written “Please Don’t Swear,” and over the orchestra appeared the gentle admonition, “Don’t Shoot the Pianist—He’s Doing His Damndest.””
—Administration in the State of Colo, U.S. public relief program. Colorado: A Guide to the Highest State (The WPA Guide to Colorado)