1847 - made his way to Glasgow to take up up an engineering apprenticeship with James Gray & Co. 1854 - set up, on his own account, as a consulting engineer and designer. 1859 - first contract was for compound engines and water tube boilers, of his own design, for the Anchor Line's ship Ailsa Craig. 1862 - in partnership with James Mathie, purchased land at Scotland Street on the south side of Glasgow, and established the firm of James Howden & Co. to manufacture engines and boilers. 1882 - patents the Howden System of Forced Draught. 1904 - became involved with James Finlay & Co., in a process for curing tea. 1912 - was involved in secret work for the Admiralty, for whom he made a recoilless gun using a non-explosive (pneumatic) propellant.