Alexander Graham Bell National Historic Site more, see Bras d'Or Lakes. Alexander Graham Bell National Historic Site Alexander Graham Bell National Historic Site is a property in Baddeck, Cape Breton, Nova Scotia, Canada, overlooking the Bras d'Or Lakes. The site is a unit of the national park system, and includes the Alexander Graham Bell Museum, the only museum in the world containing the actual artifacts and documents from Bell's years of experimental work in Baddeck. This site was designated a National Historic Site in 1952. The museum features artifacts donated in 1955 from the Bell family's personal museum, located in the Kite House at Beinn Bhreagh.
Alexander Graham Bell 1876, Bell focused on improving the electromagnetic telephone and never used Gray's liquid transmitter in public demonstrations or commercial use. The question of priority for the variable resistance feature of the telephone was raised by the examiner before he approved Bell's patent application. He told Bell that his claim for the variable resistance feature was also described in Gray's caveat. Bell pointed to a variable resistance device in Bell's previous application in which Bell described a cup of mercury, not water. Bell had filed the mercury application at the patent office a year earlier on February 25, 1875, long before