These were operated both from the ship's lighting circuit, through a motor generator, and alternatively by a stand-by battery, which by means of an automatic switch could be introduced in the circuit should the main supply fail. There was also a separate telephone system for intercommunication between a number of the chief officials and service rooms, through a 50-line exchange switchboard. A number of the pantries and galleys were also in direct telephonic communication. _Wireless telegraphy._--The wireless telegraphy system was worked by a Marconi 5-kilowatt motor generator. The house for the Marconi instruments was situated on the boat deck close to the bridge. There were four parallel aerial wires extended between the masts, fastened to light booms; from the aerials the connecting wires were led to the instruments in the house. There were two complete sets of apparatus, one for the transmitting and one for receiving messages, the former being placed in a sound-proof chamber in one corner of the wireless house. There was also an independent storage battery and coil, in event of the failure of the current supply, which came from the ship's dynamos. _Submarine signaling._--The Submarine Signal Co.'s apparatus was provided for receiving signals from the submarine bells. Small tanks containing the microphones were placed on the inside of the hull of the vessel on the port and starboard sides below the water level, and were connected by wires to receivers situated in the navigating room on the port side of the officer's deck house. _Various._--The whistles were electrically actuated on the Willett Bruce system. The boiler-room telegraphs, stoking indicators, rudder indicators, clocks and thermostats were also electrical. The water-tight doors were released by electric magnets. _Emergency circuit._--A separate and distinct installation was fitted in all parts of the vessel, deriving current from the two 30-kilowatt sets above mentioned, so that in the event of the current from the main dynamos being unavailable an independent supply was obtainable. Connected to the emergency circuit were above 500 incandescent lamps fitted throughout all passenger, crew, and machinery compartments, at the end of passages, and near stairways, also on the boat deck, to enable anyone to find their way from one part of the ship to the other. The following were also connected to the emergency circuit by means of change-over switches: Five arc lamps, seven cargo and gangway lanterns, Marconi apparatus, mast, side, and stern lights, and all lights on bridge, including those for captain's, navigating, and chart rooms, wheelhouse, telegraphs and Morse signaling lanterns, and four electrically-driven boat winches. These latter, situated on the boat deck, were each capable of lifting a load of 15 hundredweight at a speed of 100 feet per minute.