Moody Mansion had this interesting intercom system that consisted of these brass bell-like things. They were in most of the rooms and each one connected to a one of many bell-like things placed a row in a room downstairs. So presumably an "operator" in the central room could talk with somebody in any other room. Or, more likely, the other way around: I imagine the Moodys used it to place orders with the staff. An intercom for the steampunk set.