Geoffrey Bell’s Shell Film Unit short (produced by Arthur Elton) turns the history and physics of power transmission—from lever and pulley to the toothed gear—into a crisp lesson, blending live action with Francis Rodker’s animated diagrams to show how gearing underpins modern industry. Often cited as a model of clear scientific exposition.

Geoffrey Bell’s Shell Film Unit short (produced by Arthur Elton) turns the history and physics of power transmission—from lever and pulley to the toothed gear—into a crisp lesson, blending live action with Francis Rodker’s animated diagrams to show how gearing underpins modern industry. Often cited as a model of clear scientific exposition.