He started his career as an apprentice weaver but changed to civil engineering, becoming a pupil of a lock carpenter on the Leeds and Liverpool Canal in 1811.

He continued his training on a dry dock at Troon harbour, on Craigellachie Bridge and as an agent on the Edinburgh and Glasgow Union Canal.

Non-railway contracts included Liverpool Haymarket, the Manchester and Sheffield Junction Canal and the Shannon navigation.

Mackenzie also made investments, which included ironworks in Wales and France, housing in Liverpool and estates in Scotland.

An inscription on the pyramid door reads: "In the vault beneath lie the remains of William Mackenzie of Newbie, Dumfriesshire, Esquire who died 29th October 1851 aged 57 years.