The defense of our coast has lately occupied a prominent place in the eyes of the public, if one may judge from the numerous magazine articles, newspaper references, and Congressional reports, showing both action and inaction. That eventually we shall take some means of adequately protecting our coast, no one can doubt; the question that naturally arises in one's mind is, whether proper action will be taken before or after an attempt is made upon our great maritime centers. Whatever may be the method adopted—purely military, purely naval, or a judicious mixture of the two—the conveying of intelligence from one point of the coast to the other will be of the utmost importance. With fortifications, we shall always need stations from which the movements of the enemy and the number and character of the vessels can be reported. And when we have a defending fleet, we shall need, in addition, to be able to convey such information to our fleet as will enable them to meet the enemy and frustrate his designs. Even should we have a Navy commensurate with our wealth and importance among the other great nations, we still should need the assistance of shore observers to enable us to defend properly our great length of coast line.
The English naval maneuvers of August, 1887, plainly illustrate the necessity of properly located signal stations along the coast. In the operations of Squadron "A" in the English Channel, the general idea was that the British cruisers had lost touch of an enemy's fleet that had put to sea with the intention of damaging the English ports in the Channel and in the Thames and Medway, while avoiding, if possible, the British fleet. Lookout stations were organized by Admiral Hewett, commanding the force on the defensive, at the Lizard, Start, Portland Bill, St. Catherine's, Beachy Head, Dungeness, and the South Foreland; these were always in telegraphic communication with each other and with Portsmouth, Devonport, Portland, and Deal, They were of the greatest service, but the facilities for communicating with the fleet were very imperfect, depending entirely upon the dispatch-boats, and for this purpose Admiral Hewett had only the Mercury, the Rattlesnake, and three torpedo-boats, and these had to be diverted from their legitimate duties as scouts, etc., to convey telegrams. The attacking fleet was first sighted from the Lizard at 1.50 A.M. This news was received by Admiral Hewett, then off Portland, at 6.15 A.M.; at the same time he received a second telegram of 2.20 A. M. He sent in for further news, and received at 10.15 A.M. telegrams from the Lizard of 4.50, 5.15, 6.47, and 8.15 A.M. 42 minutes was the greatest length of time taken for a telegram to reach Portland, but from that station to the Admiral it required from 3h. 33m. to 5h. 25m. When the telegram first arrived, he was no miles from Falmouth; as the attacking squadron left there at 1.30 P.M., the defense had only 7 hours to make that distance. Waiting for further information, the defense did not sail until 10.30 A.M., when they proceeded at full speed for Rame Head, 80 miles away. Early intelligence would have enabled the defense to have regained touch of the attacking squadron, and possibly to have saved Falmouth.
In the proceedings of "B" Squadron off the Irish coast, lookout stations were organized by the defending force at six points, but, the attack having been sighted by the fleet of the defense early in the operations, they were little used.
An ideal system of transmitting intelligence coastwise and to seaward during a naval war would be one in which observation stations, connected by telegraph lines, were established at certain intervals along the coast: at each station, trained men with the necessary instruments for receiving and sending visual signals; at certain of these stations, pigeon-lofts for furnishing pigeons to lookout vessels and receiving from them reports, and also for dispatching birds with information to the outside stations of the fleet; also lofts at such stations as, from the position of the telegraph lines, are liable to have their connections interrupted, the birds being used to maintain communication when the lines are cut. All coast lines to be connected with the interior lines, whenever practicable, in order to give additional security. The instruments necessary are heliographs, electrographs, semaphores, and, at the most important stations, captive balloons. By means of observation vessels also, furnished with signal instruments and pigeons, the point towards which the enemy is making would be known, and his progress along the coast followed by the observers, so that the defending fleet might meet him, or, if acting as a flanking fleet, follow him up and engage him at the critical moment. If the enemy's fleet break up into detachments, the course of each will be known to the admiral commanding the defense, and he can oppose the enemy with similar detachments, or keep his fleet together and overwhelm the smaller bodies with his united force. Thus, at a comparatively small cost, the effective strength of the fleet would be greatly increased, to the greater security of the defense. In times of peace these signal stations could be utilized by the Life Saving Service and Weather Bureau, and for the purpose of sending the usual commercial intelligence. As will be seen, the system adopted by the French approaches very closely the ideal one.
Signal Stations.
England.—The proprietors of the "Shipping Gazette and Lloyds List" have established signal stations with which ships can communicate at ten points, and the committee of Lloyds have also established, or are in the course of establishing, signal stations at twenty other points. The stations, where in operation, are available to ship-owners for reporting to them the passing of their vessels, by telegrams despatched direct from the signal stations. Flags and distance signals are used. There are many semaphores established on the French, Italian, and Portuguese coasts, and one has recently been established at the island of Lissa (coast of Austria). A semaphore has also been erected at Santander, Spain. The semaphore or signal stations have, wherever practicable, the means of intercommunication by telegraphic wire, and are connected with the chief metropolitan, provincial, and foreign telegraph stations.
England has no stations prepared for time of war, but it would not be difficult to organize a system, as the Coast Guard already act as signal-men for the meteorological office, and as a part of the weather bureau system. There are 548 Coast Guard stations on the coasts of England, Scotland, and Ireland.
Canada.—Canada is fairly well provided with means of signaling for commercial purposes. There are 26 electro-signal stations in operation, in accordance with the international code of signals: three on Newfoundland, at Cape Race, Langley or Little Miquelon, and Cape Ray; two on Cape Breton Island, at Low Point and at Cape St. Lawrence; four in the Magdalen Islands; four on Anticosti; four just north of Chaleur Bay, at Point Monquereau, Cape Despair, Cape Rozier, and Fame Point; and nine in the St. Lawrence river, all on the south bank, except one on the Brandy Pots. These are connected by telegraph lines and cables with one another and with Quebec. There are also numerous telegraph stations along the coast, where signal stations might be established.
Italy.—In Italy there are 32 semaphore stations, all but three connected by telegraph lines. These are at Ponza, Tremeti, and Ventotene. There are several semaphore stations on the coasts of Denmark, Portugal, and Spain, and on the coast of France they are numerous.
Day Signals.
Semaphores, French.—The semaphores are the instruments for visual signaling established at the entrances of ports, upon the islands or the elevated points of the coast, above the buildings called electro semaphore stations. The object of the semaphores is to place the maritime authorities in communication with the ships of war or merchant marine that pass within sight. For this object, the stations are connected among themselves and with the telegraphic system of the state by short lines. Close by each station is placed a wooden mast rigged with a yard and with horns supplied with halliards, that allow the use of the conventional signals, and the flag signals of the international code. The lookouts can signal to the vessels at sea the orders and information that are sent them by the prefect of the maritime district or the minister. They receive questions from the ships, which they should answer, and information to be transmitted to the maritime authorities. In addition to this they can transmit private telegrams.
The semaphore is a hollow iron mast turning on its heel, carrying a disk and three arms that move in the same plane. The disk placed on the top of the mast should always be perpendicular to the direction of the vessel or communicating semaphore. The disk should be so placed by the lookout that the ship will see it on the right-hand side of the mast. The disk, being thus always on the right, can take several positions that serve to indicate the book in which the signal must be read. The arms, by the various positions in which they are placed, signal the numbers representing the words to be signaled.
There are six signal books given to a semaphore station, 1st. The semaphore signals. 2d. The telegraphic dictionary used by the naval forces. 3d. Geographic vocabulary. 4th. The official numbers of the boats. 5th. Boat tactics. 6th. International code. The semaphore signals are divided into three parts. The disk can take five different positions that indicate in which book or in which part of the semaphore book the numbers are to be found, 1. The disk at rest along the mast, the arms indicating a number, represents the signals in the third part of the semaphore book. 2. Inclined downward at an angle of 45°, the arms indicating a number, it represents the signals in the telegraphic dictionary or geographic vocabulary. 3. Horizontal and alone, it indicates the signal front of the semaphore, or that the station wishes to communicate or that it understands the signal. If the arms indicate a number, it represents the signals in the first part of the semaphore book. 4. Inclined upwards at an angle of 45° and alone, it annuls the signal that follows; if the arms indicate a number, it represents the signals in the second part of the semaphore book. 5. Turned vertically upwards, it represents the distant signals of the international code.
Semaphore.—English.—The semaphore signals must always be read off as distance signals, the position or direction of the arms indicating respectively the pennant, the ball, or the flag. The disk at the top of the semaphore mast remains in the position indicated whilst signals are being made by the code.
Semaphores for Vessels.—All officers must have encountered the difficulty of making out flag signals at times. If the wind is in the wrong direction, or if there is no wind, or if the haze or smoke prevents the colors from being readily distinguished, flags are very unsatisfactory. This becomes important, not only when communicating with signal stations and in the ordinary maneuvers of the fleet, but also in battle signals. Admiral Freemantle, in his valuable paper on Naval Tactics, says: "A word about signals. Our present flag signals have stood the test of years of evolutions, and have scarcely been changed for the last quarter of a century, but they are inapplicable to action in the present day, for the simple reason that while guns' crews and officers in conning towers are more or less fully protected, the signal-man, his halliards and his flags, are exposed to machinegun fire. The semaphore has been tried for evolutions, and if the semaphore can be fairly trusted, I would suggest a plated tower for the signal-men, or a portion of the conning tower being kept apart for their use, whence a large semaphore should be worked in action. It has been suggested that the arms of this semaphore should be worked from the top of a 'military mast' in our turret ships, which seems worth a trial."
Lieutenant J. F. Meigs, U.S.N., reports as follows: "The use of semaphores, consisting of two arms, which may be placed at various angles with a vertical post, is much favored in the British Navy. Many ships have now a semaphore on each quarter and on each bow, so that signals may be made clear of the ship's masts; and masthead semaphores, having longer and larger arms, are now fitted to mastless ships. They are operated by a crank and endless chain, the position of the crank corresponding exactly with that of the semaphore arm. The use of two flags, instead of one as is customary in our service, is approved, as being more rapid than the one-flag method. In one or two signals which I saw transmitted, the flags or semaphores were operated very rapidly and apparently without fear of mistake in either sending or reading; but I was, of course, unable to judge of the celerity, as I did not know what message was being transmitted."
Distance Signals.—In 1876, Lieutenant T.B.M. Mason, in a paper entitled "Two Lessons from the Future," suggests that as flags are unreliable, we should use solid figures, such as balls, barrels, cones, double cones, and a combination of barrel and cone. These to be made of colored bunting; when not in use to be closed up like Japanese lanterns. We have already a distant signal code, being a combination of square flags, triangular flags (pennants), and balls. The solid figures suggested by Lieutenant Mason are superior, as they present the same surface to all points of the compass, but for distance signals and for battle signals they should be of uniform color. The semaphore will take the place of other day signals at ordinary distances as a method of communicating between vessels and between shore and ship. For battle and distant signaling, the solid figures of uniform color will be used. In addition to these when the smoke becomes thick, Japanese day signals will be used. They consist of bombs which when exploded throw out various shapes; they can be thrown sufficiently high to explode well above the smoke, and as the thick smoke in ordinary circumstances does not rise very high, they would be visible from the tops. They would also be used in some cases by lookout vessels and scouts to warn the fleet or shore stations of the approach of the enemy. Shapes should be used to distinguish the vessels of the fleet, and when wrapped in smoke, an occasional bomb thrown up to indicate to the admiral the position of his vessels. It will be very necessary in the heat of battle to be able to distinguish rapidly between friend and foe, and it may add greatly to the completeness of a victory if the admiral, by being able to make out the position of his vessels, can send reinforcements where needed.
Heliograph.—The following description of the heliograph is taken from the Instructions for Use of the Service Heliograph, prepared by First Lieutenant R. E. Thompson, 6th Infantry, and approved by the Chief Signal Officer:
"The sun mirror has an unsilvered spot at its center, the station mirror a paper disk; in other respects they are similar.
The tangent screw attachment to the frame affords the means of revolving the mirror about a horizontal axis.
The support to the frame has a conical projection accurately turned to fit the socket of the mirror bar, and grooved to receive the clamp spring.
The screen of hard vulcanized fiber is provided with a key, by which, in connection with the action of a spiral spring, it is operated to reveal and cut off the flash.
The base of the frame carries a female screw for attachment to the tripod.
The sighting rod is fitted to the socket of the mirror bar, and is clamped in the same manner as the mirrors. It carries at one end a movable disk, which, when turned down, reveals the front sight.
A piece of white paper should be slipped into the disk to receive the "shadow spot," and a slight puncture made therein coincident with the point of the front sight as guide in adjustment.
Vertical adjustment of the disk is made possible by loosening the milled slide.
The mirror bar is provided with a clamp, threaded to fit the screw of the tripod. The release of the clamp permits movement of the bar independent of the screw.
At one end is attached the tangent screw for revolving mirror about a vertical axis, and it should be observed that under all circumstances the sun mirror should be clamped to this end, while the socket at the other extremity is designed to receive the station mirror or the sighting rod.
A movable spring is placed under each end of the bar for clamping mirrors and sighting rod.
The tripods are similar, the screw of either serving equally well for the attachment of mirror bar or screen.
Both are provided with a hook for the suspension of a weight to give greater stability when required.
Signaling is effected by depressing the screen for periods of time required to display flashes corresponding to dots and dashes.
The dot is represented by a momentary exposition of the flash, and the duration of this exposition constitutes the unit of time.
The dash is represented by an exposition of the flash for a period of three units of time.
The pause between the elements of a letter is equivalent to the unit of time; that between letters, to three such units; and between words, to six units.
In setting up the instrument, spread the tripod legs sufficiently to give a good base, and on yielding soil press firmly into the ground, the head approximately level. In a high wind, ballast by hanging a substantial weight to the hook. If the legs become loose at the head joints, apply the screwdriver to the assembling screws.
See that the screen completely obscures (cuts off) the flash, also that the flash passes entire when key is depressed. The spiral spring should return the screen sharply to its normal position when key is released. If it fails to respond promptly, strengthen or replace.
Extra care bestowed on preliminary adjustment is repaid by increased brilliancy of flash. With alignment absolutely assured and the shadow-spot at the center of the disk, the axis of the cone of reflected rays is coincident with the line of sight, and the distant station receives the greatest possible intensity of light.
The distant operator is necessarily the best judge as to the flash received; if, therefore, adjustment is called when the shadow-spot is at the center of the disk, alignment is at fault. Accuracy of alignment may be tested by looking into the sun-mirror, bringing the eye into line with the unsilvered spot, the reflection of disk, and reflection of the distant station. If now the position of the eye be changed, the unsilvered spot and reflected disk will no longer cover, but the lines of their centers in all positions will intersect at the reflection of the station, if alignment be true.
The tendency of the shadow-spot to move off the disk, due to the apparent motion of the sun, is compensated for, without interrupting signals, by means of the tangent screws of the sun-mirror. The movement imparted by these screws to the mirror does not disturb alignment, as its center (the unsilvered spot) is at the intersection of the axes of revolution.
It is of the utmost importance that uniformity in mechanical movement of the screen be cultivated, as lack of rhythm in the signals of the sender entails unnecessary and vexatious concentration of attention upon the receiver. The contrast between dots and dashes should be pronounced and unmistakable. For the dot, the flash is almost instantaneous. To avoid continuity of light, release the screen at the moment of depression. For the dash, dwell somewhat on exposure, with a tendency to lengthen rather than shorten the period of duration prescribed.
The manipulation of the instrument involves but slight manual labor; the strain on the eyes, however, from the flash of the mirrors in receiving, is often considerable, but may be modified by the use of stained glasses. It will also occasionally be found advantageous to screen the eyes from the glare of surrounding objects.
Ability to read signals from the heliograph may be readily acquired, but may also be as readily lost if practice be discontinued before proficiency is attained. It should therefore be the endeavor to acquire such facility, not only in sending but in receiving, that habit will come to the aid even after the lapse of considerable time.
Minor parts of the instrument should be dismounted only to effect repair, for which purpose spare parts are furnished on requisition.
All steel should be preserved from rust, and tangent-screws and bearings from dust and grit. The mirrors should invariably be wiped clean before using. In case of accident to the sun-mirror, the station mirror may be made available as such by removing the paper disk.
For permanent stations, an eight-inch mirror is contemplated, with provision for attachment to a post, the stump of a tree, or to some other firm base, by means of screws, dispensing entirely with the tripod.
The range over which signaling may be effected by means of this instrument, under favorable atmospheric conditions, is limited only by the convexity of the earth. The square mirror is adopted in preference to the round, as containing about one-fourth more reflecting surface for practically the same packing space.
Signaling at moderate range by night may be effected by moonlight; also by the employment of artificial light. This latter fact makes possible practice with the instrument in the squad-room."
Night Signals.
For both signal stations and vessels, the electric light will be used under most circumstances, and bombs or rockets, showing various colored stars, when the circumstances make it necessary. Illuminated and electrical semaphores have been tried, and might be of use on shipboard; but for the shore stations where the electric light is not furnished, the Army flash light or brick-wood torch must be used. At the large stations the captive balloon might be tried with success. The following is a description from the Manuel du Matelot-Timonier: "The rays of electric light reflected by a mirror are thrown upon a white balloon above the reflector. The lower portion of the balloon will be brilliantly lighted and visible around the horizon. A screen placed before the reflector serves to interrupt the luminous rays, and by this means the long and short flashes are shown on the balloon. When the night is dark and damp the balloon need not be used, as the luminous trail is then very plain. The long and short flashes may also be made on the summit of a mountain or on the clouds." This latter means would be used by the lookout vessels signaling to shore when below the station's horizon. Captive balloons have been the subject of experiment when they were lighted by electric lights in the interior, or by a surrounding circle of lights, the lights being started or flashed by the touch of a key, but they have not proved a success.
Carrier Pigeons.
The carrier pigeon has been used to convey information for many years, and has proved a most useful military messenger at many sieges, etc. But the systematic use and development of them had been due mainly to private societies, until the siege of Paris, 1870-71. During that siege they were found so invaluable that the French have since made great efforts to develop their use, and now the Military Pigeon Service has become a part of the military system of almost every country in Europe. France, Germany, Austria, Russia, Italy, Spain, and Portugal all have a Military Pigeon Service. The service in France may be shown by a few words from a military paper: "An exchange of correspondence between the central authority, the governors of fortresses and entrenched camps, and the commanders of armies, is ensured." Since this the French have entered into a series of experiments at Toulon, initiated by Vice-Admiral Bergasse du Petit Thouars and the Societe Forteresse. The first attempt was to domesticate the pigeon on board the St. Louis, the artillery practice ship. In order to accustom the pigeons to the report of guns, the cote was placed near two 19-c. and two 24-c. guns that fire an average of six hundred rounds a week. The following extracts are from a letter written by the aide-de-camp of the Vice-Admiral, Ch. Duperre, Commander-in-chief and Prefect of Toulon: "These experiments were of two kinds. One, which succeeded perfectly, was to establish communication between a ship at sea and a carrier pigeon station on shore; the other, for the purpose of studying the feasibility of keeping and acclimating the pigeons on board ship, and the possibility of establishing communication between the shore and a vessel in the ofting having a pigeon-cote on board; also from one vessel to another. The experiments have demonstrated the fact that the carrier pigeon adapts itself perfectly well to life afloat, and even breeds on board ship, but they have been less conclusive in the matter of communicating between vessels, and these attempts will have to be repeated. Our naval carrier pigeon-cote, placed on the after part of the vessel, is shaped like a small Swiss cottage, with an inside capacity of 3 cubic metres, and can receive eight couples of pigeons. In the rear are the traps by which the pigeons enter and leave the loft, and in front is a door opening into it. For the purpose of ventilation, a number of screened apertures are made in the fore and aft partitions that can be closed at pleasure. Inside the loft are two tiers of plaster nests, separated from each other by a light partition and covered with a roof; each nest is numbered. The feed and water pans are on the floor of the loft, which is slightly raised from the deck and covered with a thin layer of dry sea-sand."
Germany has the most complete military system in the world, and all its fortresses communicate with central points by means of pigeons. The whole of the northern coast is studded with pigeon stations, which are under control of the Minister of Marine. Experiments have been made by the naval authorities on homing pigeons on board men-of-war, so that messages may be sent to the ship from shore. It is said that the birds experience no difficulty in recognizing their own ship amongst a number of others. Austria is gradually completing a carrier-pigeon system for military purposes. The Russian system is still imperfect. There are 12 pigeon stations established in various parts of Italy, under the supervision of the engineer in territorial command at Rome. There are stations at Massowa and Assab for intercommunication between those places. The pigeons of each station are divided into as many groups as there are places to be communicated with, and these groups ply the same line always. Communication between the island of Maddalena and Rome (240 kiloms., all sea) has been kept up in all weathers, and pigeons have arrived close to Naples from Cagliari (450 kiloms.). During the squadron maneuvers reports were sent by pigeons, and often arrived many days before the dispatch vessel sent at the same time.
There are only a few stations in Spain. In Portugal there are pigeon stations at Lisbon, Oporto, Setubal, Tameas, Vedras Novas, Elvas, and Mafra. In Denmark all carrier pigeons are private property, but the War Office has recognized the utility of the pigeons by granting money prizes for some of the races. France is the only country that has made careful experiments and adopted a system connecting the fleet and the coast. The first trouble was that the noise of the guns frightened the pigeons; but by rearing them near the guns, they soon became accustomed to the noise, and when liberated from the various vessels of the fleet during target exercise, would form groups above the smoke, sometimes mingling together, but never losing their own ship. Messages have been sent to the shore in a number of cases, but the experiment of communicating between ships has not been quite successful. Still it may be developed so that scouts sent out in certain directions from the fleet can send back information by the pigeons, and telegrams from shore can be sent to the fleet when beyond the range of heliograph or electrograph.
United States.
While there has been no attempt to establish a system of signal stations, we have several government establishments, whose operations stretch along our coast line, that might be used in creating a system of naval coast signals. There are numerous light-houses and light-ships that are under the management of the Light-House Board; about 300 of these are in good positions for signal stations, and about 2700 men are employed in this service. Many of the army stations along the coast, under the Weather Bureau, are connected by telegraph lines and cables. On July 1, 1887, there were 331 miles of sea-coast line in operation. The Army have transferred a portion of their lines to the life-saving service, and many of the life-saving stations are connected by telephone lines. Most of the stations along the coasts of New Jersey, Virginia, and North Carolina have the telephone. There are 203 life-saving stations on the Atlantic, Pacific, Gulf, and Lake coasts. From the above it may be seen that a complete system of signal stations could be put in operation with very little additional expense, and when these services form a part of the Naval Reserve, they can be readily adapted to war uses while still fulfilling their important peace duties.
Homing Pigeons.
There is ample material in our country for establishing pigeon stations. There have been many fanciers devoted to the sport for some years. The Federation of American Homing Pigeon Fanciers includes a large number of clubs scattered over the country, and several journals are devoted to this subject. Lieutenant V. L. Cottman, U.S.N., in charge of the Branch Hydrographic Office in New York, has been kind enough to take a great interest in the subject, and has collected considerable information from the fanciers in the neighborhood of that port. This shows that there is great enthusiasm among the pigeon fanciers, and that they have not confined themselves to training their birds for races over land, but have also made experiments from seaward. From 1855 until the laying of the Atlantic cable, homing pigeons were used to take the news from the transatlantic steamers to the Sandy Hook telegraph station and thence to New York. The pilot boats have experimented with the birds at various times, and birds have been taken out in various steamers and yachts and let fly when out of sight of land. The birds of the Plainfield Club, New Jersey, have been liberated at sea many times, and F.R. Stevens and J.H. Doane, of that club, have federation records for birds liberated 300 miles from Plainfield and 100 miles from land.
There is, of course, great difference in the birds as to speed and reliability. Some fanciers say they are utterly useless in stormy weather and fogs, while others maintain the contrary. Mr. Stevens had two birds return from Manassas, Va., to his loft in a heavy rain and fog, and they made 695 yards per minute. About five hundred miles is the limit that can be attempted over the sea, and the best birds can do this in from 13 to 14 hours. In making these long flights they are liberated early in the morning, so that they may reach their loft before dark. A loft for homing pigeons has been started on board the New Hampshire at Newport, R.I., and the Army Signal Office have established a pigeon station at Key West. This station is being conducted in a systematic manner and according to the most approved principles. They have birds already trained to bring back messages from 100 miles out from any positions to the eastward, and before long they will have birds for any distance up to 400 miles. This is a commencement that can be readily extended, and it costs the Government but very little. The fanciers throughout the country are ready to give the Government their hearty support, and will assist with their experience in any experiments that may be undertaken; and it is to be hoped that when we have a fleet we may have a complete pigeon service for naval purposes, and this, with a system of naval coast signals, will enable our fleet to be handled in the most effective manner for the defense of our coast.