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If a force acts on the electrons to move them in a particular direction, then they will all drift in the same direction, although still in a somewhat haphazard fashion, but there is an overall movement in one direction. Over time, this scale buildup will result in the overheating of the heat exchanger. Telephone wires, electric-light wires, and a large majority of telegraph wires in European cities are, however, as in America, carried over house-tops or on poles. I think these facts have sufficiently demonstrated that for long lines of telegraph, stretching from city to city, here in America, pole lines, which can be cheaply built, easily repaired, and where the wires can be removed from the retarding influence of the earth and the inductive influences on each other, are decidedly superior to underground lines. On the French Atlantic it is usually about thirteen, although as many as seventeen have sometimes been sent. The recorder was first used experimentally at St. Pierre, on the French Atlantic cable, in 1869. This was numbered 0, as we were told by Mr. White of Glasgow, the maker, whose skill has contributed not a little to the success of the recorder. Armored cable is often referred to as "BX cable," though this is technically a specific branding of armored cable.

The first clear message was sent through the cable on 13 Aug., and it continued working till 20 Oct., during which period 732 messages passed through the cable, what is electric cable and then it finally broke down ; probably the insulation had given way owing to the excessively strong currents used at first in working it. The speed of working even the ordinary instruments is limited; serious trouble appears in attempting to use fast-working machines, or automatic senders, and the use of the telephone is impossible. On an ordinary cable of about a thousand miles long, the working speed is about twenty words per minute. We feel that there is no possibility of things going on for ever as they have done for the last six thousand years. In the former we have a small coil suspended between the poles of a large magnet-the magnet enclosing the coil, which is also free to rotate round its own axis. Strength and flexibility : The cables which are used for any purpose must have a large insulation and should be easily installed. If these wires are run on poles, they not only disfigure the streets, but seriously interfere with the operations of firemen in case of fire, as we have repeatedly seen during the last few years.

The first step by a few of them was to attempt to slow things down. As with any project, there are a few hints, tips and guidelines that will help to prevent any issues arising and ensure that the process is successful every time. The practical advantage of this extreme delicacy is, that the signal waves of the current may follow each other so closely as almost entirely to coalesce, leaving only a very slight rise and fall of their crests, like ripples on the surface of a flowing stream, and yet the light spot will respond to each. This cable is laid in a trench by the road-side, and comes to the surface only inside the telegraph-offices in the cities. In this way hundreds of single wires would be gathered into small and inoffensive cables, and the enormous wooden structures would be replaced by small cable supports of brick or iron. The cost of one wire by itself is vastly larger than where many are run together, the cost of the pipe and for laying being not much greater for fifty wires than for one, and the cost of single wire cables being greater per mile of wire than multiple wire cables, so that the expense of putting such a system as one of our telephone exchanges entirely under-ground would place the cost of the instruments entirely out of reach of the subscribers.

If telephones were required in every house, as are gas and water, such a system might be practicable, but at present that is not likely to be the case. If, then, the present method of running wires overhead is objectionable, and the expense of running them under-ground is so great as to put the cost of telephones, electric lights, and other electrical appliances out of the reach of would-be users, how are the wires to be run? The Niagara deviated from the great arc of a circle on which the cable was to be laid, and the error was traced to the iron of the cable influencing her compass. The cost of piping and chambers would be nearly as great for one hundred circuits as for one thousand, as the cost of chambers and the labor of excavating and filling would be the same; so that the cost for one hundred wires may be estimated at $50,000 per mile, or $500 per mile per conductor. In any other city than Paris, the above figures would be very greatly increased by the cost of under-ground piping and chambers to contain the cables. In Paris, all the wires are carried in the sewers under-ground.