What people are saying - Write a review
We haven't found any reviews in the usual places.
Other editions - View all
Wireless Telegraphy: Its History, Theory and Practice - Primary Source Edition
Archie Frederick Collins
No preview available - 2013
action adjusted aerial wire alternating current amperes antenna apparatus armature arranged battery Branly Braun break capacity charge closed closed-circuit coefficients coherer condenser conductor plugs connected in series consists core detector diameter dielectric direct current disk disruptive discharge distance earth effect elec electric oscillations electric resonance electric waves electro-magnetic electrolytic employed energy ether ether waves Fessenden filings frequency galvanometer glass Hertz high-potential inches increased induction coil inductor insulated internal circuit interruptor Leyden jar light Lodge magnetic Marconi maximum mercury metal method Morse register non-syntonized number of turns obtained open-circuit open-circuit oscillator operated opposite oscillator balls oscillator system plate polarized potential primary circuit primary coil produced radiator receptor relay resistance resonator system secondary coil shown in Fig siphon recorder Slaby-Arco spark spark-gap surface syntonized tapper telephone receiver terminals theory tion trans transformer transmitter tube tuned turns of wire vertical wire vibrations wave length wireless telegraphy
Page 47 - The discharge, whatever may be its nature, is not correctly represented (employing for simplicity the theory of Franklin) by the single transfer of an imponderable fluid from one side of the jar to the other; the phenomena require us to admit the existence of a principal discharge in one direction, and then several reflex actions backward and forward, each more feeble than the preceding, until the equilibrium is obtained.
Page 8 - ... accompanying changes of form, and which is perhaps sufficient to induce, in the inventive and sanguine philosopher, a considerable degree of belief in the association of the radiant form with the others in the set of changes I have mentioned. " As we ascend from the solid to the fluid and gaseous states, physical properties diminish in number and variety, each state losing some of those which belonged to the preceding state.
Page 65 - I can account for these phenomena only by supposing the long wire to become charged with electricity, which by its re-action on itself projects a spark when the connection is broken.
Page 47 - ... polarity was always conformable to the direction of the discharge, he found that when very fine needles were employed, an increase in the force of the electricity produced changes of polarity. About a thousand needles were magnetized in the testing helices in these researches. This puzzling phenomenon was finally cleared up by the important discovery that an electrical equilibrium was not instantaneously effected by the spark, but that it was attained only after several oscillations of the flow....
Page 68 - It will be shown in a later section that the power dissipated in a resistor is equal to the product of the resistance and the square of the current.
Page 8 - The immense differences in their weights almost disappear ; the remains of difference in colour that were left, are lost. Transparency becomes universal, and they are all elastic. They now form but one set of substances, and the varieties of density, hardness, opacity, colour, elasticity and form, which render the number of solids and fluids almost infinite, are now supplied by a few slight variations in weight, and some unimportant shades of colour.
Page 48 - It is easy to explain this law, if we assume that the discharge of a battery is not a simple motion of the electricity in one direction, but a backward and forward motion between the coatings, in oscillations which become continually smaller until the entire vis viva is destroyed by the sum of the resistances.
Page 8 - If we conceive a change as far beyond vaporization as that is above fluidity, and then take into account also the proportional increased extent of alteration as the changes rise, we shall perhaps, if we can form any conception at all, not fall far short of Radiant Matter; and as in the last conversion many qualities were lost, so here also many more would disappear.
Page 93 - ... ends of these wires. 1 have just made an electro-magnet which, with a single pair of 7 inch plates, gives (even at the moment of making battery communication) a shock as strong as the shock from about thirty ar forty pairs of plates. In making electro-magnets which are to be connected for the purpese of obtaining increased electric intensity, care must be taken not to solder the thin to the thick wires of the magnets, and to leave both ends of the thin wires projecting...