In august 1834, Scottish naval engineer and shipbuilder John Scott Russell (1808 - 1882) was riding his horse along the Union Canal, a 31 mile (51km) stretch of water that connects the cities of Edinburgh and Glasgow, when he noticed a peculiar phenomenon. A canal boat being pulled by two horses abruptly stopped, sending a ripple of water forward. Russell followed the ripple on horseback as it flowed some eight or nine miles per hour. “After a chase of one or two miles, I lost it in the windings of the channel,” he wrote. “Such was my first-chance interview with that singular and beautiful phenomenon which I have called the Wave of Translation.”
Russell soon began experimenting with such waves building a 30-foot water tank in his backyard to run experiments. The wave of translation, or solitary wave (as Russell’s theory became known as), demonstrates a relationship between the wave’s speed and height related to a channel’s depth. Running a set equation based on these values results in a solution, known as a soliton.
While Russell is often known for his other achievements, including revolutionizing boat hull construction and many architectural projects, it wasn’t till almost a hundred years later that his theories around the solitary wave were widely utilized to understand complex wave systems.
The Edinburgh portion of the Union Canal lies in the westerly neighborhood of Fountainbridge. Just a stone’s throw away is Exchange Place, hidden behind Edinburgh’s Meat Market facade. On the ground, a visitor will find a series of brass plaques commemorating Russell’s monumental discovery. They inform the onlooker of the history and significance of this Victorian-era innovation.
Know Before You Go
Look down at the paving stones in the small alley to find the brass plaques commemorating John Scott Russell's discovery. The alley can be found in between BlackRock (Exchange Place, One, 1 Semple St, Edinburgh EH3 8BL, United Kingdom) and FarrPoint (2, Exchange Place, 5 Semple St, Edinburgh EH3 8BL, United Kingdom).
You can also visit the John Scott Russell Aqueduct, which crosses over the City of Edinburgh Bypass (A720), near the neighborhood of Sighthill. There's also a plaque on the west side of Bridge 11 along the Union Canal that commemorates the portion of the canal where Russell discovered the solitary wave in August 1834.