The passage of commerce through the Forth and Clyde Canal was conducted mainly by horse-drawn barges until the 1850s, when the introduction of the marine screw that did not damage the canal banks, provided the opportunity for steam propulsion. The steam- or screw-lighter is generally acknowledged to date from 1856, when the barge, Thomas, was fitted with a steam engine and screw propellor by the Forth and Clyde Canal Company, and allowed to ply between Grangemouth and Glasgow. Steam lighters on both the Clyde and the Forth were not unknown by this time and there are some inklings that other experiments were also in progress such as the following court proceedings from 1854 that mentions a screw or lighter on the Canal. “Sheriff Criminal Court.—The following cases at the instance of the Procurator Fiscal have been disposed of summarily at this Court, before Mr Sheriff Robertson, during...