Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 146,690 pages of information and 232,152 images on early companies, their products and the people who designed and built them.
of Blackhall Iron Works in Dublin
Also see Courtney, Stephens and Co
1845 Courtney & Stephens, agricultural implement factory and iron works, 1 Blackhall Place. Courtney, Henry esq., 24 Fitzwilliam Place (This was the home address of Henry the iron founder) 
1849 Pedestrian suspension bridge at Straffan House by Courtney & Stephens. The location of this elegant bridge is now a golf course 
1867 Reference to the new President of the Institution of Civil Engineers of Ireland, William Anderson, 'then of the firm of Easton, Amos and Anderson, who had begun his career in Ireland as a partner in Courtnay, Stephens and Co., of Dublin, which, during his connection with it attained by far the first position in Ireland in the construction of railway bridges and other large and important public works.'  Clearly, 'Courtnay' was a misprint in the source document.
A Courtney & Stephens hand crane is preserved at Connaught Harbour, Portumna, on the River Shannon. See photographs, reproduced with permission from 'Irish Waterways History' website