When a number of stations are in view from one station and it is desired to send a message to all or more than one station, some preconcerted signal, as a rocket, a red light, or some peculiar flag or torch signal, should be designated as a signal for general attention. Upon noticing this signal all the called stations reply, and then observe the calling station. This plan is useful when two or more stations can, at the same time, read the signals from the one station, and thus together receive any information to be transmitted from it. When a signal station is to communicate with two or more stations, a telescope should be firmly fixed bearing on each, when practicable, and so far apart that those communicating with one station will not disturb the other party. _Commencing the message._--Every message is invariably commenced by the signal "Hr" or "Anr." Sometimes at the commencement of communication a preface will be sent in order to give some preparatory information to the receiving station regarding the number or character of messages about to be sent. For example, "Hr 8," means "I have eight for you" or "Hr ck 300" means a three hundred word message follows. _Sending and receiving._--Before the commencement of a message, care should be taken that all the letters and characters thereof are entirely and correctly understood by the signalman whose duty it is to call the same to the sending operator. The message is read off by the "reader," who first calls off a word and then spells it out letter by letter. The "reader" should observe the signals of the operator and invite his attention to any apparent errors. When the last letter of a word is announced this fact will be communicated to the sending operator. At the receiving station the man at the telescope will call off each letter as received and not wait until the completion of a word. On reaching the end of a word announcement of this fact will be made to the recorder. _Breaking._--If the sending operator discovers that he has made an error which will probably render the sense of the message unintelligible at the receiving station, he will make the signal "BK" and recommence the message, beginning at the last word correctly sent. When the receiving station fails for any reason to get correctly what is being sent, the sending station is interrupted by the signal "GA," followed by the last word correctly received. The message will then be recommenced by the sending station at the point indicated. _Discontinuance of transmission._--When all the messages on file at any station have been sent the signal "NM" in Morse or "Cease signaling" in the army and navy system, according to which code is authorized, will be the concluding signal of the sending station. When a signal station is operated only during the daytime, the signal "GN" will be transmitted after all business filed up to the hour designated for closing has been dispatched.