From Graces Guide
Henry Dennis (1825-1906)
1907 Obituary 
HENRY DENNIS, born at Bodmin, Cornwall, in 1825, commenced his engineering career in the office of the Borough Surveyor of Bodmin, Mr. Henry Coom.
On completing his training he joined the engineering staff of the Cornwall Railway, which now forms part of the Great Westernsy stem, and subsequently he was employed in surveying the coast-line and taking soundings in Padstow harbour with a view to the construction of a breakwater.
The construction of mineral railways in the south of Spain during 1856 and 1857 brought him into contact with the mining branch of the profession, to which his subsequent career was principrtlly devoted.
Returning to England in the following year he was entrusted by the mining firm of Messrs. John Taylor and Sons with the construction of railways for the Llangollen Slate and Slab Company’s mines in Denbighshire. Having settled in the district, Mr. Dennis turned his attention to its mineral resources, and from that time forward he took a prominent part in the development of the Wrexham coalfield, as well as of lead mines and stone quarries in the neighbourhood.
He became manager of the Bryn-yr-Owen Colliery, and afterw-ards managing director of the Wrexham and Acton collieries and the Ruabon Coal and Coke Company; director of the Minera Lead Mining Company, and chairman of the Westminster Brymbo Coal and Coke Company, the Snailbeach Lead Mining Company, and other undertakings.
He also carried on a private practice, and, as engineer, was instrumental in obtaining parliamentary powers for supplying Ruabon and several other districts with water and gas.
He built the Glyn Valley railways, the Wrexham District tramways, and the Snailbeach Railway. He owned and managed the Cefn freestone quarries, and was identified with various other undertakings in the district. He also acted as consulting mining engineer to several large estates in North Wales.
Mr. Dennis was for some time chairman of the North Wales Coalowners’ Associntion and their Mutual Indemnity Company, and he also represented the Association on the Coal Trade Conciliation Board.
In 1904 he served the office of President of the Mining Institute of Great Britain. The claims of business left him little leisure for public affairs, but he served for a time as an Alderman of the Denbigh County Council, and was also a Justice of the Peace for the county.
Agriculture was his hobby, and he acquired a considerable reputation as a breeder of sheep.
He was taken ill immediately after a journey by motor-car from his home, New Hall, Ruabon, to his Cornish residence at Bodmin, and died at the latter place on the 24th June, 1906, in his eighty-second year.
Mr. Dennis was elected an Associate Member of The Institution on the 31st May, 1881.