1780. Blomefield redesigned the Armstrong cannon that had been previously used by the British forces, replacing it with a cannon that was simpler in design, lighter, and had more effective recoil restraint. The cannon weighs 6429 lbs, with a range of 2000 metres. Roofs are not original Mediterranean design of Martello towers, but a temporary snow roof was later added to the open gun platform two years after the tower's construction protects the gun and keeps out the large amounts of snow. The addition of a roof is a common feature on Canadian Martellos. The original roof was installed in 1849. In 1921 a windstorm removed the original wooden and tin roof. Parts of the roof date to the reconstruction that followed in 1925, but the majority of the present roof dates from the 1970s and is not removable for safety reasons. Despite being one of the most sophisticated Martello towers designed and built by the British, Murney Tower quickly became obsolete due to improvements made in military weaponry and ship design. Present day In 1925, the museum was opened as a museum for the public by the Kingston Historical Society. It continues to be operated by the Kingston Historical Society as the Murney Tower Museum through the summer months (May - Labour Day in September). Displays include three cannons (32-pounder), period uniforms, muskets, and other mid-19th century military artifacts. Although 14 Martello towers were built in Canada, only 9 are still standing, 4 of them in Kingston. Currently, only Murney Tower Museum is open to the public. Fort Henry has two towers that resemble Martello towers, however, they are branch ditch towers. Designations In 1930 Murney Tower was designated a national historic site due to its sophisticated design. In 1989 the Kingston Fortifications were designated a National Historic Site of Canada. In 2007, the Rideau Canal and Kingston Fortifications (including Murney Tower) were recognized as a UNESCO World Heritage Site. It was recognized as having played an important role in the defense of British North America and in enabling Canada to develop its own political and cultural identity References External links Murney Tower - Kingston Historical Society Infrastructure completed in 1846 Towers in Ontario Buildings and structures in Kingston, Ontario National Historic Sites in Ontario Museums in Kingston, Ontario Military and war museums in Canada