The History of Fog Signals - Part 1

Beeeohhhh, the mournful sound of the fog signal hooting and echoing across a bay shrouded in gray. It seems as thought that sound must have always been part of the bayscape.  But, in fact, fog (correctly termed, sound) signals are relative newcomers to the field of navigational aids, and the most popular of them, the diaphone and diaphragms, are of the twentieth century.