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A.T. system accumulators alarm-points alarms alternating currents alternating-current amount amperes apparatus armature arrangement batteries cable cells cent central station charge conductors connected copper core cost Crompton curve cut-outs diagram diameter disc discharge distributing mains dynamo dynamometer effect efficiency electric light electro-motive force electrometer employed engines experiments fact field-plates figures Fire Brigade fire-alarms fire-telegraphs fuse Gaulard give given glass Grosvenor Gallery heat hysteresis increase inductors influence machine installation instrument insulation iron Kapp Kapp's kilowatts lamps Leyden jar London magnetic magnetic circuit magnetisation maximum means measure metal method millimetres mutual induction obtained output paper paraffin parallel placed plates practical Preece primary circuit Professor Ayrton proportion question resistance ring rules secondary circuit self-induction serious fires Siemens Society specific inductive capacity street call-points supply telegraph telephone temperature to-night voltmeter volts wattmeter watts wire Zipernowski
Page 726 - When the wire cd was surrounded by an iron tube, or when it was replaced by an iron wire, no perceptible effect was obtained, confirming the conclusion previously arrived at that the magnetism of the iron is unable to follow such rapid oscillations, and therefore exerts no appreciable effect.
Page 724 - ... nature of a regular vibration, he availed himself of the principle of resonance. According to this principle, an oscillatory current of definite period would, other conditions being the same, exert a much greater inductive effect upon one of equal period than upon one differing even slightly from it.* If then two circuits are taken, having as nearly as possible equal vibration periods, the effect of one upon the other will be diminished by altering either the capacity or the co-efficient of self-induction...
Page 117 - Gallery installation, and been found to act in a perfectly reliable manner. In the present paper I have only dealt with what may be called elementary principles in the construction of transformers. As, however, the application of transformers is a matter of far greater importance to our profession at large, I trust you will allow me to say a few words on this subject, not with the object of imparting information, but in the hope that a discussion of real practical value may be the result. Up to the...
Page 577 - В may pass very near them without touching. A brass ball D two inches in diameter is fixed on the end of the axis that carries the plate B, and is loaded within at one side, so as to act as a counterpoise to the revolving plate B. The axis PN is made of varnished glass, and so are the axes that join the three plates with the brass axis N O.
Page 600 - Author. earth, and the other (the receiver-spring) with an insulated piece of metal called the receiver, which is analogous to the " prime conductor " of an ordinary electric machine. The point of contact of the earth-spring with the carriers is exposed to the influence of an electrified body (generally an insulated piece of metal) called the inductor. When this is negatively electrified, each carrier comes away from contact with the earth-spring, carrying positive electricity, which it gives up,...
Page 736 - ... 0. Other positions of the secondary circuit. — Dr. Hertz made numerous observations with the secondary circuit in other positions, but in no case were any phenomena observed which were not completely in accordance with theory. As an example of these consider the following experiment : — The secondary was first placed in the horizontal plane in the position v (figure 8*), and the air space was in the position at relatively to the primary.
Page 768 - Royal United Service Institution ; Journal. Science Abstracts — Physics and Electrical Engineering. Society of Arts ; Journal. Society of Chemical Industry ; Journal. Society of Engineers; Transactions. South Wales Institute of Engineers, Cardiff; Proceedings. Staffordshire Iron and Steel Institute, Dudley ; Proceedings. Surveyors' Institution ; Transactions and Professional Notes.
Page 725 - When these were replaced by much larger spheres the sparking distance was diminished to a small fraction of a millimeter. Similar results were obtained on connecting the micrometer terminals with the plates of a Kohlrausch condenser. When the plates were far apart the increase of capacity increased the sparking distance, but when the plates were brought close together the sparking distances again fell to a very small value. The simplest method of adjusting the capacity of the micrometer circuit is...
Page 742 - A A'. Its effect was to displace the null points through about 10° towards the pile. A block of asphalt (D, in Fig. 10), weighing 800 kilograms, and measuring 1.4 meter in length, 0.4 meter in breadth, and 0.6 meter in height, was then used in place of the books, the plates being allowed to rest upon it. The following results were then obtained : (1) The spark at the highest point of the circle was now decidedly stronger than that at the lowest point, which was nearer to the asphalt. (2) The null...
Page 759 - ... theory that the propagation of electro magnetic induction also takes place by means of waves. They therefore afford a confirmation of the Faraday-Maxwell theory of electrical action. He points out however that Maxwell's, in common with other electrical theories, leads to the conclusion that electricity travels through wires with the velocity of light, a conclusion which his experiments show to be untrue. He states that he intends to make this contradiction between theory and experiment the subject...