From Minutes of Proceedings of the Institution of Civil Engineers, Volume 14, 1855

John Armstrong was born at the village of Ingram, Northumberland, on the 13th of October, 1775; his early years were spent in agricultural pursuits, and he scarcely had any opportunity of acquiring more than the rudiments of education; he then became the apprentice of a millwright, and the first mechanical engagement he received was under the late Mr. Thomas Dodgin, millwright, of Newcastle-upon-Tyne, by whom he was employed at the White-Lead Works, Bill Quay, where his Brother was the foreman.

About the close of the last century he settled in the neighbourhood of Bath, where he ultimately was engaged in the construction of the Pulteney Bridge, for a portion of which he became the contractor.

In the year 1804 he was employed, under the late Mr. Jessop, in the construction of the Docks, at Bristol, where he remained until their completion; all the lock-gates, swivel-bridges, cranes, steam-engines, pumps, sluices and other machinery being constructed under his immediate directions.

For some years he remained chiefly at Bristol, practising as a Millwright and Engineer, and generally engaged in such works as the lock-gates at Lydney, in the Forest of Dean, the gates and sluices of the Congresbury Drainage, &c.; he was then engaged under Sir Robert Smirke upon the construction of the bridge across the Severn, at Gloucester, and in 1821 his services were secured by Mr. Rennie and subsequently by Mr. Telford, for superintending the construction of the new arch of Rochester Bridge, on the completion of which he undertook the direction of the works for the Grosvenor Canal.

His next engagement was at the Thames Tunnel, under the late Sir Isambard Brunel, from whence his services were transferred to Messrs. Bramah, by whom he was employed, among other works, upon the construction of the lock-gates for the St. Katherine Docks, and subsequently in the direction of their building speculation at Calverley Park, near Tonbridge Wells.

At that period (1831) the post of City Surveyor, at Bristol, becoming vacant, he was unanimously elected to the position by the Paving Commissioners, and fulfilled the duties to their entire satisfaction, until within the last week of his life.

He was a very valuable public officer, and the loss of his services to the city will be felt, not in his own department only, as his general amenity of disposition and impressiveness of manner enabled him to become a mediator in many cases, so as to avoid litigation. He had in the course of his varied practice, during a long life, amassed a great store of useful information, which he knew how to apply with judgement; he was a sound good mechanic and millwright, of the school now fast passing away; his steadiness and punctuality could always be relied upon, and his decease, on the 17th of March, 1854, at the advanced age of seventy-eight years, was acutely felt by his family and a large circle of friends.

He was elected an Associate of the Institution of Civil Engineers, in the year 1828, and during his residence in the Metropolis was a constant attendant at the meetings.