From Graces Guide
John Donkin (1802-1854), son of Bryan Donkin
1824 John Donkin, Great Surrey Street, Blackfriars, became a member of the Institution of Civil Engineers.
1855 Obituary 
John Donkin was born at Dartford, Kent, on the 20th of May, 1802 ; he was the eldest son of the late Bryan Donkin, one of the earliest Members of the Institution, whose name will always be remembered with affection by those who had the good fortune to enjoy his personal acquaintance, and with respect by the world for his uprightness of character, his general acquirements as an Engineer, and more especially for the improvements introduced by him into the machinery for making paper and for printing, to which his time was for many years chiefly devoted.
After the usual course of education, he was sent for a time to Paris, where he acquired a knowledge of the French and German languages, which was eventually very useful to him.
He was taken at an early age, into the works of his Father, at Bermondsey, and was the fellow-pupil of the late Mr. H. R. Palmer, Mr. Gravatt, and other Members of the profession. His energy, perseverance, and application soon induced his admission to partnership with his Father and Mr. Wilks, and he contributed materially to the great, degree of perfection at which the paper-machines eventually arrived.
Subsequently his attention was much directed to designing paper-mills and other establishments on the Continent, for which the machinery was constructed at the Bermondsey Works; but latterly he was compelled, with regret, to devote himself almost entirely to the commercial part of his business, leaving the technical part chiefly under the control of his brothers Bryan and Thomas, who were associated with him; without, however, diminishing his interest in the progress of science, and more particularly of that branch to which he had especially directed his attention.
He was a Fellow of the Geological Society and became an early Member of the Institution of Civil Engineers, having joined it in the year 1824, served on the Council from 1830 to 1833, was on several occasions Auditor of Accounts, communicated papers to the Transactions, frequently took part in the discussions, and generally exhibited great anxiety for the welfare of the Society.
His urbanity and kindness of heart caused him to be generally esteemed, and his decease, which occurred at Roseacre, near Maidstone, on the 20th of April 1854, in his fifty-second year, was deeply regretted by his family and by a large circle of friends.