Publication: Scientific American
New York, NY, United States
The Municipal Fire Telegraph.
The purpose of a Fire and Police Telegraph is to connect the various parts of a Municipality by an intelligent and co-operative law. To accomplish this it has been found necessary to adopt, for the municipal body, the precise arrangement which is found in the nervous system of the individual.
Thus, in the Fire Telegraph, now approaching its completion in Boston, there is a Central Station, which is the "brain," the common reservoir of nervous or electric force for the whole system, at which all the batteries are placed, and which is presided over by an intelligent will (the watchman or operator of the Central Station). From this centre radiate two classes of electric conductors or nerves (the iron wires carried over the houses.) The first of these, the "Signal Circuit," conveys impressions to the centre, is "afferent," "sensitive," to adopt the language of anatomy. The second of these, the "Alarm Circuit," conveys impulses from the centre, is "afferent," "motor." When any disturbance or alarm occurs at the circumference or other part of the system, it is signalized from the "Signal Boxes," which are scattered throughout the city, and which are the "sensitive extremities" of the sensitive conductors, to the Central Station, from which, after an act of intelligence and volition by the operator, an impulse to appropriate or corresponding action is sent over the "motor" nerves or conductors to the various belfries, where the electric or nervous agent animates iron limbs by means of the contraction of electro-magnetic muscles, thereby releasing powerful machinery to strike a single blow with each of the tolling hammers. By a combination of such blows, by the intelligent act of the presiding will at the Central Station, distinct signals, or any others may easily be struck.
This presents at once an outline of the Municipal Fire Telegraph. The analogy with the living system has been thus wittily stated by the editor of the Boston Commonwealth: "Suppose a live coal drops on your toe; the nerves of sensation give an instant signal to the brain, that is, a feeling of pain. The brain then, by an act of will, conveyed to the muscles along the leg by the motor or alarm nerves, rouses the said muscles to their duty in the case, and the result is, that the coal is kicked off. The municipal fire-alarm arrangement is conducted on this very plan." The perfection of this analogy is a guaranty, in addition to the various ends of security and intelligent action which are thus obtained, that the arrangement is in conformity with a natural law.
A chief peculiarity of the Fire Telegraph, as a mechanical system, will be seen at once from the sketch above given. It develops the motor functions of the electric circuit, at a distance. Hitherto the telegraph has been chiefly used to convey intelligence, which is its sensitive function. Its application to the development and control of power at a distance, either by its own electro-magnetic energy, or by bringing into action other machinery, which is its muscular or motor function, is to give a wide extension hereafter to the uses of the agent electricity. In the fire system both of these vital functions of the telegraph, so to speak, are employed, and also related to each other in their natural order. In proportion as civilization advances, the telegraph is thus to constitute the nervous system of organized social life, relating all the parts and making possible a more perfect co-operation than could otherwise be obtained.
The Municipal Electric Telegraph, applied to purposes of Fire and Police, was first described in its general principles by Dr. Wm. F. Channing, in 1845. In 1848 its adoption was recommended by Mr. Josiah Quincy, Jr., the Mayor of Boston, and some experiments were made. In 1851 an elaborate plan was finally presented by Dr. Channing to the Government of that city, which was adopted, and is the basis of the system which has been constructed and successfully tested, though not as yet publicly introduced in Boston. The present mechanism and arrangement of the system have been elaborated by Dr. Channing and Mr. Moses G. Farmer, the able