Look up at 477 Congress Street, the Time and Temperature Building, originally the Chapman Building, a 14-story office tower on Congress Street in downtown Portland, Maine. It replaced Preble House, itself a successor to the mansion of Commodore Edward Preble. The tower takes its popular name from the large three-sided, four-element eggcrate display screen on the roof that flashes the local time and temperature.
When it rose in 1924 it was built as a 12-story building and even housed Maine’s first indoor shopping center on the ground floor. Across Preble Street you can pick out the 10-story Fidelity Trust Building; together, until the 1970s, these were Portland’s only skyscrapers. The sign was added in 1964, and in the 1970s the Portland Savings Bank ran a summertime contest to guess when the sign would first register a temperature of 90 °F (32 °C).
Visible from miles away, including from Peaks Island across the harbor, the building is a familiar landmark people rely on for the time and temperature, and mariners use it as they sail into Portland harbor. Trace that roof sign's glow toward the harbor, where sailors still watch for the time and temperature.