Piers note: No. 5. Fort Clarence: West Ditch, Back View (1870) showing loopholed Escarp with Postern (with small, raising drawbridge) leading into inner work, and Casemate Battery in Counterscarp beyond. To left appears top of sandstone Martello Tower (Duke of Clarence's Tower); 1870. Looking Southeast from crest of north glacis.
Reference: Royal Engineers Nova Scotia Archives number 6824 (Piers 5)
Nova Scotia Archives — https://archives.novascotia.ca/royalengineers/archives/
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