Although the sound of a foghorn is becoming increasingly infrequent even in maritime settings, it would be hard to miss the deep, long rumble of the horn when it bellows. Perhaps some of us have even heard this sound while out at sea, without knowing exactly where it was coming from. The foghorn is a signal which uses sound to warn vehicles, usually ships, of navigational hazards such as rocks, shoals, and other ships, in foggy conditions. What is perhaps even lesser known than the foghorn itself, is that the first automated steam-powered foghorn was invented right here in Canada, by civil engineer Robert Foulis.
The story of the foghorn is inextricably linked to the story of its inventor. Robert Foulis was a Canadian inventor, civil engineer, and artist, who emigrated to Canada from Scotland in 1818. He eventually settled down in New Brunswick in 1822, where he worked as a civil engineer and land surveyor.
The story goes that while walking home one day in 1835, Foulis heard his daughter playing piano, and noticed that he could only hear the very low notes through the fog. He realized that this principle could be applied to the problem of fog signals. At the time, the generally foggy Saint John’s harbour had both a cannon and a bell-tower to warn incoming ships of danger during periods of low visibility. The cannon was inconvenient and dangerous, as it had to be manually fired in these foggy conditions, which could last many days. And as Foulis realized that day, the clangs of a bell didn’t carry through to sailors nearly as well as a much lower-pitched sound with a longer wavelength would.
Foulis went on to prove both the bell and the cannon futile, by inventing a steam-powered, automated horn that produced long, low, notes at specific intervals during foggy weather. The foghorns used a vibrating column of air to produce an audible sound. He also devised a coding system based on horn sound intervals to communicate the location of hazards to ships.
His invention was eventually installed on Partridge Island in 1859–the first foghorn to be installed anywhere in the world. There was a long period of dispute between Foulis and the New Brunswick government over crediting Foulis with the invention. Although he was formally credited as the inventor by the New Brunswick legislature in 1864, he never patented his invention nor made any profit off it.
The foghorn revolutionized maritime navigation. It was adopted worldwide as a means to decrease the occurrence of ship crashes during times of poor visibility. Although the foghorn has largely been replaced by GPS and radar technology, modern foghorns are still used in some harbours today. Nevertheless, few people know about Richard Foulis. His story is a testament to the amazing contributions that engineers make to society, which unfortunately, can go unacknowledged at times.
OSPE always strives to increase public awareness of the impact that engineers have on society. That’s why, in honour of Canada 150, we’ve been celebrating feats of Canadian engineering throughout the year. We will continue to highlight engineering projects of all shapes and sizes, to showcase incredible Canadian inventions like this one. Check out OSPE’s growing Canada 150 list for many more examples of Canadian engineering innovation.