Another important part of the maritime life is the foghorn. The purpose of the foghorn is simply to warn vessels at sea during times of heavy fog not to approach too closely or risk running upon the rocks which would tear the bottom out of the vessel and sink it.
The foghorn was invented by a Scottish-born Canadian named Robert Foulis of New Brunswick around 1853. The device was steam-powered. The first foghorn was installed on Partridge Island in 1859. It was built by T. T. Vernon and called the Vernon-Smith foghorn. He used the blueprints of Foulis who hauled Vernon into court. Foulis proved that Vernon had used his blueprints without permission. The court sided with Foulis and declared him the inventor of the foghorn but Foulis never obtained a patent for his invention and so never made a penny in profit. Captain James Newton also claimed to be the inventor of the foghorn but his claim is easily refuted.
The Partridge Island steam-powered foghorn from an 1865 watercolor sketch by J. C. Myles.
The Kobba Klintar foghorn in 1942.
The Nash Point foghorns are extremely loud. Foghorns make use of low frequency because they have much longer wavelengths than high frequencies and so travel much farther and hence warn vessels at sea far earlier. This twin-horn design is called a diaphone foghorn.
http://www.youtube.com/watch?v=55ze6-Bza_w
The sound of a diaphone foghorn.
Alki Point lighthouse, 1914.
The Daboll Trumpet was a foghorn invented by Caledon Leeds Daboll. Daboll Trumpets were used exclusively in the United States from the 19th century until the 1920s. Rather than steam-power, the Daboll Trumpet ran on a single horsepower coal-fired engine. The type shown here was used on the Great Lakes.
Daboll Trumpet.
http://www.youtube.com/watch?v=mUL4xAcy7uo
The sound of a Daboll Trumpet.
Lizard Point diaphones in Cornwall, England. This is a true siren-type which forces air thru a revolving cylinder or disc with holes in it.
Not a photo but an Andrew Wyeth painting.
Point Au Pere foghorn.
http://www.youtube.com/watch?v=Rn0dat-8CNM
Very cool portable Japanese foghorn made by the Tokyo Siren Company.
Diaphones on Lake Superior at Split Rock, Minnesota.