Casquets lighthouses per ton of ship when vessels passed the rocks and in turn he paid Trinity House 50 pounds per year for the right to run the lighthouses. The lighthouses reverted to Trinity House in 1785. They were converted to oil lamps with metal reflectors which were first used on 25 November 1790; and upgraded again with apparatus to rotate a beam of light in 1818. This had a clockwork mechanism which was wound up every hour and a half and gave one flash every 15 seconds. The lighthouses were badly damaged and the lanterns smashed in a severe storm on
History of lighthouses in Canada where all material and construction costs would be borne by Great Britain. The so-called Imperial Towers were tall conical towers of brick or masonry construction where, in some cases, the granite was quarried and prepared by Scottish stonemasons, and shipped to the colony as ballast. By 1850's standards they must have seemed Imperial, i.e. built to withstand the ages. Henri Maurice Perrault designed lighthouses in Lotbinière, Quebec (1860); Pointe-aux-Trembles, Quebec (1862); L'Islet, Quebec (1865); Port St. Francis, Quebec on Lake St. Peter (1865); Isle aux Prunes opposite Verchères, Quebec (1866); and a movable lighthouse at Isle aux Raisins, Quebec (1867).