Marine diesels through a 1938 engineering source

Edgar C. Smith's 1938 engineering history supplies the period vocabulary and describes the machinery in its contemporary context. Smith places spirit, petroleum, paraffin, and heavy-oil engines beside the marine steam turbine as propulsion changes that altered shipping. Petrol engines already powered small racing craft. Heavier oil engines displaced boilers and reciprocating machinery in harbor craft and challenged steam in all but the fastest ships. The comparison frames the video's central question: why oil and compression-ignition machinery became attractive at sea.