Sherlock, David (1850–1940), barrister and peat industrialist, was born 27 March 1850 in Rahan Lodge, Tullamore, King's Co. (Offaly), second son among four sons and two daughters of David Sherlock (1814–84), lawyer and MP, of Stillorgan Castle, Co. Dublin, and his wife Elizabeth, youngest daughter of John Thierri, chairman of Ireland's board of excise. Sherlock received his early education at St Stanislaus College, Rahan, and may have spent a brief period at TCD, but there is no record that he ever graduated. He trained as a barrister at King's Inns and was called to the Irish bar (1872), but was perhaps better known for his role in the promotion of the Irish peat industry. By the 1850s peat was proving to be an economical form of energy and was successfully used to fuel German trains; in Ireland the Great Southern & Western Railway Co. conducted its own experiments using turf as train fuel (1874) and for smelting iron. Recognising the potential growth of the industry, Sherlock began the Rahan Peat Works (c.1880), which successfully carried out fuel and peat moss production for the next fifty years.
Sherlock was responsible for bringing to Ireland Professor A. Werner Cronquist, a peat expert from Stockholm, Sweden, who declared that Irish bogs were more suitable for fuel and moss production than Swedish ones. Encouraged by his assertion, Sherlock set about developing his business. A successful barrister of independent means, he could afford to experiment with different machinery; however, neither an engineer nor a scientist, he was easily swayed by the claims of manufacturers and as a result was said to have purchased and tested nearly every turf-cutting machine available on the Continent (1883–1917). His 1,000 acres of land produced a significant amount of machine-sod peat and peat moss that was easily transportable, for his bog was only half a mile from the Grand Canal and he laid a narrow-gauge portable tramway between the two. He built a large turf turbine to produce the requisite energy, and his home, Rahan Lodge, was the first house in King's Co. to be wired with electricity from such a source. From the turf and its extracts he was able to produce paper, cloth, paint, ink, iodine, tiles, and bricks; assertions that he invented peat moss, peat briquettes, and a turf-cutting machine remain unproved.
When his father retired from parliament in March 1880, Sherlock briefly considered standing for election, but withdrew for reasons unknown at the last minute; he later stood for election as a home ruler in the College Green division of Dublin city (1885) but lost to the city's lord mayor, T. D. Sullivan (qv). Sherlock served as both DL and JP for King's Co., and when he died in 1940 (the exact date is unknown) he was buried in the grounds of St Cartage's church, Rahan.
He married (12 May 1873) Elizabeth, daughter of Edward Murphy of the famous brewing family, of Castle Connell, Co. Limerick. They had three sons: Col. David Christopher Eustace Sherlock (6 June 1879–18 February 1938), who was in the Royal Artillery, served in the first world war, and was awarded the Croix de guerre; Gerard Lourdes Sherlock (b. 13 December 1884), who joined the Royal Flying Corps and was the first man from King's Co. to fly a plane; and Maj. Edward Mary Sherlock (b. 8 May 1886).