In signalling by the navy code, the sentence to be sent is looked up in the code-book and its corresponding number is obtained. This number is never more than four figures, on account of the necessity of setting the signal with the least delay. The number having been obtained, the quartermaster in charge of the signal-chest proceeds to bend the flags representing the numerals to the signal halliards, so as to read from the top down. These flags represent the numerals from one to nine and cipher, and there is a triangular pennant termed a repeater, which is used in a combination where one or more numerals recur. The numbers refer to those found in the general signal-book, in which are printed all the words, phrases, and sentences necessary to frame an order, make an inquiry, indicate a geographical position, or signal a compass course. Answering, interrogatory, preparatory, and geographical pennants form part of this code; also telegraph, danger, despatch, and quarantine flags. The signal, having been prepared, is hoisted and left flying until the vessel to which the message has been sent signifies that it is understood by hoisting what is called the answering pennant. If the number hoisted by the flag-ship is a preparatory order for a fleet movement, it is left flying until all the vessels of the fleet have answered, and then is pulled down, the act of pulling the signal down being understood as the command for the execution of the movement just communicated. It is often necessary for a man-of-war to communicate with a merchant vessel, or with some other war-ship belonging to a foreign country. For this purpose the international code is also carried in the signal-chest. These signals are those in general use by all the merchant navies of the world for communication by day at sea. There are eighteen flags and a code pennant, corresponding to the consonants of the alphabet, omitting x and z. The code pennant is also used with these signals. If a message is to be sent at night, the Ardois system of night signals, with which all our vessels carrying an electric plant are fitted, is employed. These signals consist essentially of five groups of double lamps, the two lamps in each group containing incandescent electric lamps, and showing white and red respectively. By the combination of these lights letters can be formed, and so, letter by letter, a word, and hence an order, can be spelled out for the guidance of the ships of the squadron. These lamps are suspended on a stay in the rigging, and are worked by a keyboard from the upper bridge. On the smaller ships of the service, those which are not fitted with electric lighting, Very’s night signals are used. This set includes the implements for firing and recharging the signals.