Scientific American Supplement, April 20, 1895, page 16087:
A SEMAPHORE TELEGRAPH STATION.
WHEN a vessel passes in sight of the shores of a civilized country it is customary to communicate with the rest of the world, receiving the latest news, and in turn announcing any dangers to which the vessel has been subjected. The facilities for communication have been greatly increased by the introduction of the semaphore. The utility of the semaphore has been so widely recognized that it is difficult for a vessel to pass unperceived along any of the French coasts. The semaphore is naturally located on a high point from which an unobstructed view of the sea can be obtained, and is placed either on the top of a house or tower. On the pole are several signal arms and the station is connected with the national telegraph system. There are usually two signal poles, one of which is devoted to the display of meteorological signals which announce the probable conditions of the weather, the predictions coming from the observatories. These signals are made of canvas and are shaped liked cones or cylinders, so that they can be seen from whatever direction they are viewed. The cone as shown in the engraving announces the probability of high north winds. The same pole is used for the signals of the international code, which are made with the aid of eighteen flags. This international code which is used to-day by all maritime nations, is made up by grouping flags, four or more of which represent not only words and phonetic signs, but ideas and whole phrases. Unfortunately, the use of flags is not sufficiently rapid for long conversation and signaling becomes difficult at great distances, because the colors blend together, and in the case of calms or very brisk winds it is nearly impossible to distinguish the signals. It is to avoid these inconveniences that the semaphore has been introduced for marine signaling, permanent arms being secured to the semaphore, which give signals analogous to those on the railways or those of the old Chappe telegraph. The actual signals are made by three arms which are articulated to the pole. These arms can be freely moved to various positions with the utmost precision by the mechanism. Eighteen signals can be made by combinations of these arms, which correspond to the eighteen flags of the international code.
As shown in our engraving, the arms are manipulated by means of chains which pass around drums which are turned by handles. The whole signalling apparatus is mounted on a platform which can be turned so as to permit of the signals directly facing the vessel which is spoken. Messages from vessels are transmitted to their destination, the charges of course paid by the recepient of the telegram. For our engraving and the foregoing particulars we are indepted to L'Illustration.