thumb|300px|The grave of Thomas Smith, Old Calton Cemetery, Edinburgh
Thomas Smith (6 December 1752 – 21 June 1815) was a Scottish businessman and early lighthouse engineer. He was appointed as the first Chief Engineer to the Northern Lighthouse Board in 1786.
Early life
Smith was born in Broughty Ferry near Dundee on 6 December 1752. His father, a skipper, drowned in Dundee harbour while Thomas was still young. As a result, his mother encouraged him towards a career onshore, leading him initially into ironmongery. While his widowed mother remained in Broughty Ferry, Smith went on to establish himself in Edinburgh.
Professional career
In Edinburgh Smith founded and appears to have been the sole proprietor of a successful business in lamps and oils called the Greenside Company's Works. but the innovations devised by Smith gave his lamps quadruple the power of standard oil-lit lamps without any kind of reflector.
The success of Smith's work in street lighting provided him with the connections and qualifications which resulted in his appointment as Chief Engineer to the newly formed Northern Lighthouse Trust (now Northern Lighthouse Board) in 1786. He was commissioned to build the first four modern lighthouses and promptly dispatched south to pick-up technical expertise from an English lighthouse builder (possibly John Smeaton, who built the pioneering third Eddystone Lighthouse in the 1750s, or perhaps Ezekiel Walker or William Hutchinson).
The first of his lighthouses—Kinnaird Head (1787)—had 17 whale-oil lamps backed by parabolic reflectors and was said to be the most powerful light of its day before moving to the then newly built 2 Baxter's Place at the head of Leith Walk in 1798/9.
The relationship between Thomas Smith and his step-son Robert Stevenson proved to be close and admiring. Though Stevenson's mother had intended him for a career in the ministry, he instead became a keen assistant to his step-father's works and was formally apprenticed to Smith in 1791. This relationship was further cemented by an unusual circumstance: in 1799 Stevenson married his then 20-year-old step-sister Jane.
Little is known about Thomas Smith's own son James except that he left home to found his own ironmongery business, but whether this was due to some rift with his father is unknown.