Fire Alarm Telegraph

THE ALARM TELEGRAPH.

Completion of the System — Test of Its

Merits — Complete Success — True Time

from the Big Bell.

At length the fire alarm telegraph, for the completion of which the public have for so long a time been on the qui vive, has been finished and is ready for operation. The final arrangements were made yesterday, and searching tests of its workings instituted. Yesterday afternoon Chief Engineer Hare and Wm. N. Ogden, Esq., of the Committee made the circuit of all the boxes and tested the perfection of the workings of all the circuits.

Last evening, on an invitation from the Fire Alarm Committee, the members of the Pittsburgh Councils and a large delegation of the members of the Allegheny Councils, together with the members of the pres and some invited persons, met the Committee at the central office in Wilkins Hall, there to witness the practical illustration of the workings of the system when in full operation, and to judge for themselves of its success or failure.

Mr. J. M. Gamewell, of the firm of Gamewell, Kennard and Company, whose system this is, made a few brief remarks, explaining clearly the principals and workings of the arrangement. As our readers are probably aware, there are forty-one signal boxes distributed throughout the city in . . . [illegible text] . . . accessible locations, and within easy reach of each other. Each of these boxes has an outer and an inner door. Within the inner door is a little system of clock work which is wound up and set going by a key which projects outside of the inner door. The running down of this machinery causes to revolve a small "break wheel," with cogs and breaks corresponding with the number of the box. These cogs and breaks open and close successively the circuit connecting with the central office, and so automatically, give the alarm. The key to the outer door of the box is left with some responsible person near the station, and when a fire in that district is discovered, the holder of the key opens the door, pulls down the alarm key, the machinery is set in motion and the alarm flies over the wires to the central office.

At the central office the alarm is given in two ways: by a small alarm bell, which sounds the number of the box, and by a register which records the number with a pencil on a slip of paper. The last is only used as a safeguard to the office operator. He marks upon the paper the date and the hour, and files it away to prevent misunderstandings.

From the office to the various engine houses, signal stations and the great alarm bell, are wires by which the alarm of fire is instantly transmitted. This transmission might be effected by manipulating the wires directly at the battery without the intervention of complicated machinery, but this primitive method of operating would lead to divers mistakes and would probably render the alarm telegraph a nuisance instead of a blessing. Therefore the Repeater is employed to transmit the intelligence of fire on the principle that automatic machinery is far more accurate and reliable in its action than human hands can ever become. This "repeater" works almost precisely on the same principal as the "break-wheels" in the signal boxes. It is furnished with tow dials, supplied with hands, like a clock. The minute hand on each of those dials is placed at twelve, and the hour hands adjusted according to the number of stations. If the number is sixteen, one hour hand is placed at one and the other at six. They key is pulled and the alarm is transmitted through the different circuits to the alarm bell, to the gongs in the engine houses, and to the little bells in each of the signal boxes.

To prevent false alarms that might possibly occur, the "Switch Board" is . . . [illegible text] . . . as a safeguard. No manipulation of the repeater, or of the wires at the battery could convey an alarm outside, unless the circuit is effected by the adjustment of the keys or switch-board, which adjustment is effected by the operator after the alarm is received at the office.

To secure the ability of transmitting the alarm, even though the repeater be out of order, a system of operator's keys is provided by means of which it can be affected.

In order that the circuit may be fully and regularly tested, the "Tail-tale Clock" is provided. This is an ordinary clock with an extraordinary attachment. By its machinery a little paper disc marked with sections is made to revolve slowly. A little bell connected with this strikes three times an hour to draw the operator's attention. At the striking of this bell the operator must cause the current to pass through the entire circuit, and if the circuit is complete, a little pencil dots the fact on the paper disc. If the duty is neglected, a blank space on the paper at the spot that should be marked, tells the tale.

So much, in brief, for the explanation given last night by Mr. Gamewell. At its conclusion a key was placed in the hands of President McCauley, of the Select Council, with the request that he would go to some box of his own selection and transmit an alarm to the office. He proceeded to box No. 17, on the corner of Wood and Sixth streets, and at fifteen minutes past eight, pulled the key. In one half minute the strokes of seventeen were sounding on the great bell, on all the engine gongs, and on the little box bells. In two minutes from the first tap of the bell the engines began to arrive on the spot. In six an a half minutes the Relief had reached the place all fired up, having come its distance of a mile and a quarter with a promptness that was refreshing. At this striking proof of the efficiency of the new system, all voted it a success.

We are heartily glad the good work has come to so successful an issue, on account of the city, and on account of the gentlemen composing the committee who have had the matter in hand, and also of the gentlemen constituting the firm to whom we are indebted for the system.

We will state here that an additional some-what novel and exceedingly valuable use is to be made of the great bell. From it, four times in the twenty-four hours, our citizens are to learn the correct time. At twelve o'clock, noon, and midnight, at six o'clock in the evening, and at six o'clock in the morning, the proper strokes on the sonorous body will announce the time as the stars have told it. The time of these strokes will be regulated by the proverbially correct calculations of Messrs. J. R. Reed & Co., No. 68 Fifth street. These gentlemen regulate their time by regular transit observations, made nightly with the most perfect instruments, and, therefore, the bell, guided by them, must give the most perfectly reliable intelligence. So our citizens, besides saving their property by means of the big bell, will also save their time.