John Turnbull Junior (1841-1903)
1841 Born son of John and Catharine Turnbull
1851 John senior was a Master Engineer, employing 48 men and 20 apprentices
c.1857 Apprenticed to his father at Canal Basin Foundry
c.1860 Went to Italy as one of the Glasgow Volunteers to assist Garibaldi
c.1862 Partner in Turnbull, Grant and Jack
1871 Married Margaret.
1877 Set up a consulting business, John Turnbull, Junior
1881 Consulting engineer, living in Rosneath with Margaret Turnbull 37, William Turnbull 10, Campbell Turnbull 8, Malcolm Turnbull 5, Catherine Turnbull 3, Agnes Turnbull 1
1891 John Turnbull 49, mechanical engineer, consulting, lived in Kilfinan, Argyl, with Margret Turnbull 46, William L Turnbull 20, Campbell Turnbull 18, Agnes McD Turnbull 11 
1903 Obituary 
JOHN TURNBULL, Jun., was born in Glasgow on 4th August 1841, and received his education at various schools in that city.
He commenced his engineering apprenticeship in the Canal Basin Foundry under his father.
On completing his time he went to London with two friends, and started a pattern-making business, which was very successful.
In 1848 (sic) he went and fought under Garibaldi as one of the Glasgow Volunteers, and on his return to Glasgow, he was taken into partnership with Messrs. Turnbull, Grant, and Jack of the Canal Basin Foundry.
In 1877 he started in Glasgow as a consulting engineer, and made a speciality of steam-engine work and water motors. He brought out a compound engine and invented a simple cut-off valve gear, and was the author of "A Short Treatise on the Compound Engine," the "Engineer's Guide Book," "Arithmetical Questions," and "Water Wheels and Turbines." He was widely consulted with regard to water power and steam power, and was well known as an expert machinery valuer.
His death took place at his residence in Glasgow, on 14th January 1903, in his sixty-second year.
He became a Member of this Institution in 1885, and was also a Member of the Institution of Engineers and Shipbuilders in Scotland.
1903 Obituary