This apparatus is intended for communication between the pilot-house of a ship and the engine-room, or other place. It is so constructed that by pulling a knob in the pilothouse a cylinder is rotated in the engine-room, on which cylinder is painted the desired signal, at the same time calling attention by a bell. There are also two bell hammers, which are arranged in such a way that the striking of them ensures the rotation of the cylinder to the desired signal. It is the invention of J. R. Hopkins, of Lincoln, Me., and was patented this week.