Eight Bells by Winslow Homer (1887)

The Ships Clock application will ring a bell on every half-hour in the style of the standard ship's clock. That standard has its roots in centuries of sailing ships around the world where clocks were impractical, and is still used in present-day navies. It is based on four-hour watches: each watch was on duty for four hours starting at the hour of 12, 4, or 8 (am or pm). Each half-hour during a watch was marked by a single bell and each hour by a double bell. For example, starting at 12 o'clock:

• 12:30 1 bell
• 1:00 2 bells (as one double bell)
• 1:30 3 bells (as one double, followed by one single bell)
• 2:00 4 bells (two doubles)
• ...
• 3:30 7 bells (3 doubles, one single)
• 4:00 8 bells (4 doubles)

At the end of this cycle, the pattern is repeated.