Invented the reaping machine which was a direct precursor of the modern combine harvester. Born in Auchterhouse, near Dundee, Bell studied divinity at St. Andrews University. He designed his machine in 1827 and years of testing followed. It was not brought into general use until 1843, the same year that Bell was ordained as minister at Carmyllie (near Arbroath).
In 1869, his original machine was purchased by the Science Museum in London, with a smaller model going to the Royal Scottish Museum in 1870. The latter is now displayed in the Scottish Agricultural Museum. Bell's workbench and tools can be seen at the Angus Folk Museum at Glamis.
He is buried at Carmyllie Church and is commemorated in its windows.