- Born: - Died: -
Canal and irrigation engineer, active in the first three decades of the eighteenth century. Stephen Costello sounded the River Shannon with Mortimer Heylen in the opening years of the century and worked on the unsuccessful Liffey Navigation scheme in the 1720s. The difficulties encountered on the Liffey, made the alternative of cutting a canal from Dublin more attractive, and Costello and Michael Keating investigated the possibility of a line through the Bog of Allen, which Costello concluded to be impracticable. Costello also advised Robert Molesworth about irrigation work at Breckenstown in 1720-21, at which time he was described as never having been out of Ireland.(1)
All information in this entry not otherwise accounted for is from V.T.H. & D.R. Delany, The Canals of the South of Ireland (1966), 18,32,34,98, and Ruth Delany, The Grand Canal of Ireland (1973), 11, 48,75.
(1) Killadoon papers Q/1/1, see A.P.W. Malcomson, The Clements Archive (Dublin: Irish Manuscripts Commission, 2010),136,138.