Water Tank at the Top of Pound Lane [????-????]

An 1889 map of the area shows it labelled "Hospital Tank" (see "A").  

 A search for hospital tank in HKGRO returns three results. The first two are about this tank:

• 1880. Legislation.-Schedule of All the Laws, Proclamations, Orders in Council, & C: "No.315. Tenders, Reconstructing a portion of the Retaining Wall and Sewer on the North Side of Hospital Road below the Hospital Tank."
• 1882. Public Works Return, April, 1882: "Incidental Services under $50,— to taking up 5" Water Main on Inland Lot No. 59, repairing Western Slaughter House Dam, cleaning and repairing Nos. 1 and 2 Tanks, Cowpers Tank, Hospital Tank, St. Paul’s College Tank, Glenealy Tanks, Albany Tanks, Water Mains, Stop and Fire Cocks, Supply and Service Pipes to Government Buildings,..."