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1901.] MARINE REVIEW. 21 FOSTER'S FOG SIGNALS. . The problem of safety from collision at sea has rightly been divided into three parts: First, to prevent the collision; second, to save the ship in case of collision; third, in case the ship must be abandoned, to save the passengers and crew. Foster's system of fog signalling aims to reach the root of the matter by preventing the collision, and so to make provision for the second and third parts of the problem unnecessary. This is accomplished by means of a signalling apparatus which not only warns approaching vessels that they are in close proximity, but enables each to tell the other its exact compass bearing from the other, and also the course it is steering. The same apparatus can be used for communicating by the Morse code during fogs. The great difficulty with sound signals, as distin- guished from light signals, is that they cannot be located with accuracy. Cases are on record in which two officers standing on the bridge of the same steamer have differed as much as 90° in their estimate of the direction of a fog signal, which was distinctly heard by both of them. Nothing is more common than for a vessel to turn out of its course under the impression that a certain signal is several points on the bow, when it is really dead ahead. This is what happened when the United States auxiliary cruiser Prairie went ashore in a fog off Montauk point, when bringing United States soldiers home from Cuba. Ferryboats find it impossible to navigate in thick weather because they cannot be sure of the location of the various signals that are placed along the shore and cannot find their slips. If ihe fog signals were as easily located as the lights, navi- oe would be as simple in thick weather as it is at night. Foster's system of fog signalling is designed to over- come this difficulty by making the sounds of such a char- acter that they shall announce with certainty to any person within hearing the exact direction from which the warning sounds come. This is accomplished by the use of a sound director or megaphone, which concentrates and projects various signals, first in one direction, and then in another, combined with an apparatus for varying the signal according to the direction to which it is sent. Any passing vessel must hear one of these sounds more clearly than the others, and the signal that it hears most distinctly tells it the exact direction from which the sound comes. Experi- ments made by the light-house board of the United. States have shown that when a vessel is opposite one of the megaphones, the sound sent out 'by that megaphone is overpoweringly greater than the sound from any of the others, and that at a distance of more than a mile it is impossible to hear any of the sounds except those sent by the megaphone which is pointed directly toward the listener. The apparatus is in the form of a single automatically revolving megaphone, which turns to each of the eight points of the compass in turn --west, northwest, north, etc.--and gives a signal for each point by means of a simple code of long and short blasts. All the signals which signify the general direction of west begin with the short blast, while all those signifying the general direction of east begin with a long blast. Op- posite points have opposite signals--east, for instance, being one long and one short, while west is one short and one long, so that if you learn half the code you know the other half. The full code is as follows: One long blast, the signal you hear is north of you; one short blast, it is south of you. Two long blasts, signal is north east; two short blasts, it is south west; one long and one short, it is east; one short and one long, it is west; two long and one short, it is south east; two short and one long, it is north west. When the apparatus is placed upon moving vessels for the purpose of avoiding collisions, it is so constructed that the megaphone can be easily turned, so as to give the proper signals no matter how much or how often the vessel changes its course. To accomplish this, a pointer on a dial representing a compass is shifted so as to agree with the course steered. If the vessel's course is Wi. S. W.,.for instance, the pointer is simply put on that mark on the dial. As the vessel proceeds upon her course she blows her signals automatically, giving any other vessel which may be in the neighborhood exact information as to her position. As the revolving megaphone in its circuit points toward the bow of the vessel upon which it is placed, it blows a supplementary signal of different character, such as the whistle on the smoke stack, which shows that the megaphone is then pointing directly toward the course which the vessel is steering. If this course signal immediately precedes or follows a compass signal, it gives the vessel's course. If the megaphone signals "east," and the whistle immediately follows, showing that the megaphone is pointed over the bow, the vessel must be east of you, and its course must be a little north of west. - Suppose a steamer going due east hears a signal "north" faintly, and a few seconds later hears the signal "northeast" very distinctly. She would know that there was a vessel northeast of her; but, as that vessel did not blow her course signal, there was no danger, as she could not be approaching. A few seconds later the signal "east" is heard faintly, and is followed by the course signal. The unseen vessel must be on the port bow, going on a course northwest by west. When two signals are heard with equal clearness, both louder than any preceding or following ones, the direction of the danger must be midway between the two points which are heard with equal distinctness. Previous inventions have considered it enough to indicate the course upon which the vessel proceeds; but this is a serious error, as will be seen from the accompanying diagram, in which the vessel A is in.no dan- ger from B, which has already crossed its path, but must. come into col- lision with C, which is going on the same course as B. To avoid collision in such circumstances, the position as well as the course must be accurately known.- In the position shown, the vessel B would indicate the absence of danger, because her course signal would be sounded long before the E. signal of position. The vessel C would give her position N. W., and im- mediately follow with her course signal. Reciprocal signals of danger being given 'by the vessel A at the same time, both A and C would be warned in time to turn aside, according to the rules laid down for vessels which meet each.other showing red and green. Men-of-war use this apparatus to enable the vessels of a squadron to maintain an exact position with relation to one another on the darkest night, without having to show a light of any kind. During blockades a vessel could indicate its position to the commodore at night, and the signals would be quite inaudible on shore, as the megaphone would not be pointed that way. In foggy weather, a fleet could proceed in regular order, each vessel in line advising the next one of its exact position. A very simple attachment to the signalling apparatus enables vessels to communicate with one another by the Morse code, but the messages sent are inaudible to any vessel but the one toward which the megaphone is directed, so that two men-of-war might send messages which could not be heard by the enemy. When placed upon a light-house, this apparatus is particularly useful to small boats that may be caught in a fog without a compass, because, if the sailor knows the course he should steer from the tight-house, he can get into the range of the proper signal and keep in it until he arrives at his destination. With the present sys- tem of signalling it is a common thing for ef a small boat without a compass to be aware that there is a fog signal blowing on the port hand, for instance, but quite im- possible for the sailor to tell whether he is on the north, south, east or west side of that signal; therefore, he has not the slight- est idea of which-direction he ought to A take in order to reach 'port. CD , Phis apparatus was erected at Falk- ner's island on Long island sound, and 5 thoroughly tested by a special committee appointed by the United States light-house board. The report of this committee was so favorable that the United States government immediately purchased the apparatus as it stood and asked congress for an appropriation for the erection of similar fog signals at other points. The Canadian government has also purchased the apparatus, and is erecting a signalling station at Fame point in the Gulf of St. Lawrence. The apparatus is manufactured by the Hamilton-Foster Fog Signal Co., 11 Broadway, New York, and is patented in all maritime countries. A VERY LARGE CHAIN WORKS. _ James McKay & Co. of Twenty-ninth street and Liberty avenue, Pittsburg, announce the completion of their new factory, to be known as works No. 1 (the old factory being known as works No. 2). The new factory is located at McKees Rocks, a suburb of Pittsburg, about four miles from the center of the city. James McKay & Co. have in these works the largest and most complete single plant of its kind in existence. The machinery is operated by electricity and that used for the manufac- ture of chain, such as hammers, winders, cutters, benders, testing ma- chines, etc., is entirely new and largely made from the company's own patterns and designs. A testing department contains two hydraulic test- ing machines, one with a capacity of 100,000 lbs. for light testing and the other with a capacity of close to 700,000 Ibs. The 7,000-lb. machine is the largest ever made for this purpose. With the new plant in full opera- tion McKay & Co. will have capacity of 10,000 tons of finished product annually, or in other words an increase of five times the present output. The product will range from a dog chain to the largest ship cables made, with all kinds of special chains and attachments. "Our aim," says a letter from the company, "is not only to increase our output, but also to better our already high standard of quality, and we feel that with the aid of our new machinery we are now able to manu- eS a only the highest quality, but also the most uniform class of goods.' The launch at Chicago Saturday of the Fred B. Wells, fourth steamer of the Peavey fleet, marked the building of the fiftieth boat by the Ghicago Ship Building Co. in twelve years. Low Rate Excursion to New York via B. & O.--Tickets on. sale daily until Oct. 20 with privilege of returning via Buffalo. Call at city ticket office, 241 Superior street. é Oct. 20.