Journal of the Society of Telegraph Engineers, Volume 3Published under the supervision of the Editing Committee, (London, John King & Company, Queen Street Printing Works), 1874 |
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acid action alloy Ampère's law apparatus applied arrangement battery bobbin borer bottom boucherising cable cable-current cells cent centimetres charge chemical circuit coil condenser conductivity conductor connected construction copper creosote creosoted poles cylinder decay defence deflection depth diameter direction ditto ditto duplex earth effect electrical resistance electromotive force elements employed equal experiments explosion fathoms fuses galvanometer German silver gun-cotton gutta-percha heat hole ignition inches increased induction induction coil instrument insulated iridium iron wire larch length lever magnetic means measure metals method miles mines moisture needle observed obtained Ohms ordinary paper placed plate platinum platinum wire platinum-silver poles portion position potential Preece preservative produced pulley quantity Railway relay Ruhmkorff coil ship signals sinker Society soil sound station submarine surface telegraph poles temperature tension Thomson timber tion torpedo tube weight Wheatstone's bridge wire wood zinc
Popular passages
Page 505 - For nearly two years I have felt quite sure that the proper explanation of voltaic action in the common voltaic arrangement is very near Volta's, which fell into discredit because Volta or his followers neglected the principle of conservation of force.
Page 5 - ... rest or in motion. Then, as to terrestrial magnetism, — of what its relation may be to perceptible electric manifestations we at present know nothing. You all know that the earth acts as a great magnet. Dr. Gilbert, of Colchester made that clear nearly 300 years ago ; but how the earth acts as a great magnet— how it is a magnet, — whether...
Page 480 - Society be communicated to the President and Council of the Institution of Civil Engineers for having granted the Society free permission to hold its Meetings in the rooms of the Institution.
Page 169 - On September 12th I was examining the condition of the wire in a darkened room, when a new and unexpected change revealed itself. During the cooling of the wire it was found that, just as it reached a very dull red heat, a sudden accession of temperature occurred, so that it glowed once more with a bright red heat. Illuminating the index and scale of the apparatus, which was watched by an assistant, it was at once found that the reheating of the wire occurred simultaneously with the momentary elongation.
Page 177 - The general outline of the rest of Mr. Schwendler's commmunication will be best given in extracts from his paper, which will be printed in full in Part II. of the Journal. Mr. Schwendler says : — " The currents observed at all hours of the day and all seasons of the year, in every line throughout India, may be obviously due to many different causes acting separately or conjointly. These currents I have designated - natural currents,' to indicate the fact of their being in the lines without any...
Page 24 - It will be seen that the two currents do not pass one another, as has been imagined, but that, when both stations signal at the same time, the current sent by either station acts upon the distant instrument, by determining whether the currents sent by that station shall pass through the line or the resistance-coils.
Page 505 - This amounts simply to saying that, as long as no wires are attached to the plates of a single cell, there is no difference of potential ; but that when wires are joined on, the observed difference of potential is due to the contact of the wire with that metal plate to which it is dissimilar. Again: — "When a single metal is placed in contact with an electrolyte, a definite difference of potentials is produced between them ; zinc in water becomes negative, copper in water becomes negative, but...
Page 504 - Professor Jenkin, referring to these experiments of Thomson, adds that " In cases where no known chemical action occurs, as where zinc and copper touch each other, and yet difference of potential is produced, since this involves a redistribution of electricity, a small but definite consumption of energy must then occur ; the source of this power cannot yet be said to be known "f.
Page 506 - ... contact with zinc becomes negative, in a single cell with wires attached it is the wire attached to the zinc that shows a negative potential. This he holds to be conclusive that the junction of the wire with the zinc plate is the real seat of the electrical separation ; although he admits that there may be a slight difference due to the liquid, and that different liquids may augment or decrease this difference. In another place he says: — "If the voltaic theory of the cell were absolutely correct,...
Page 14 - During all that time, let us suppose that an electric machine has been turned in the neighbouring room, and a spirit-lamp burning on its prime conductor. Keep turning the electric machine in the neighbouring room, with the spirit-lamp as before. Make no other difference but this — shut the window and open the door. I am supposing that there is a fire in your experimenting room. When the window was open and the door closed, the fire drew its air from the window, and you got the air direct from without....