The following obituary appeared in the 19 June 1889 Leeds Mercury edited by Thomas Blackburn Baines: Nearly the whole town of Tralee belonged to him.
He had an opportunity twenty years ago, when his leases fell in, of raising his rents to figures that, in some cases, would not have been considered extortionate had they been quadrupled (during the Great Hunger in Ireland).
So far as he was himself concerned, a little money went a long way, but he gave liberally to poor relations and to the development of religious work in connection with the "Brethren".
His rental income from Ireland was about £13,000 a year.Denny lived in later years at Bolton Gardens, Kensington and at another time at Islington, being then connected with the Brethren's Priory Meeting Room.
Denny studied the subject of biblical prophecy and assisted by John Jewell Penstone (1817–1902) prepared valuable charts to illustrate dispensational teaching.