John By, lt-col, Royal Engineers (b at Lambeth, Eng and bap 10 Aug 1779; d at Frant, Eng 1 Feb 1836). By was one of the greatest early engineers in Canada. He built the 200 km Rideau Canal (1826-32) from Bytown (named for him, now Ottawa) to Kingston, involving construction of about 50 dams and 47 masonry locks. Without the aid of modern construction equipment, it was completed in 5 summer working seasons. By was born into a family of Thames watermen but was admitted in 1797 to the Royal Military Academy, Woolwich. Commissioned in 1799, he served for 2 years at Plymouth before being sent to Canada in 1802. Here he worked on the first small locks on the St Lawrence R and on the fortifications of Québec.

Returning to England late in 1810, he served briefly under Wellington in the Peninsular War but early in 1812 was appointed engineer officer for the Royal Gunpowder Mills. Soon after the victory at Waterloo, munitions requirements being minimal, he was retired, but he was recalled in 1826 to build the Rideau Canal. On returning to England in 1832, despite his superb achievement, he was criticized by the Treasury Board for some allegedly unauthorized expenditures. He died, a broken man, 3 years later.