Fourth light of the upper row of the stained glass window in the staircase with the coat of arms of Sir Thomas Gresham, Horace Cullen Esq., and Sir John Watney. “Presented to the City of Londonderry by the Worshipful Company of Mercers. London: A.D. 1912”. The stained glass window was manufactured by Campbell Brothers in Belfast, destroyed in 1972 by an IRA bomb, and restored by Calderwood Glass, Newtownabbey.