Tide-Predicting Machcine No. 2, nicknamed “Old Brass Brains”, was in service at the U.S. Coast and Geodetic Survey between 1910 and 1965, when it was retired in favour of an electronic computer. It was the successor to Tide-Predicting Machine No. 1, which began operation in 1895.
So important were accurate tide predictions to operations in World War II that Old Brass Brains was used to predict tides for major ports for four years in advance to insure they would be available in case the mechanical computer broke down or was sabotaged.
