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alarm and room amalgamated amperes armature AUTOMATIC BURNER battery wire bichromate binding post burglar alarm call bell Cells Connected cells in series circuit is closed circuit is open connected in multiple connected in series connecting post current strength deflect diamond carbon dilute sulphuric acid Disque electric bells electric gas lighting electro-magnet electromotive force fire alarm fluid four cells galvanic cell galvanometer gas lighting apparatus hole hotel annunciator hydrogen bubbles inches induction coil internal resistance iron core Leclanche liquid magnet mercury metal multiple arc needle negative pole nitric acid number 16 number of ampere-turns Ohm's law ohms open circuit placed platinum polarization porous cell porous cup positive pole prisms push button ratchet ring room call rubber run a wire sal-ammoniac shown soft iron spark splices spring strip sulphate sulphuric acid teries thermostat tion valve vibrating bell voltaic cell volts Western Electric zinc plate zinc pole
Page 5 - No single battery fulfills all these conditions, however, and, as we have already intimated, some batteries are better for one purpose and some for another. Thus, for telegraphing through a long line of wire, a considerable internal resistance is of no great consequence, as it is but a small fraction of the total resistance in circuit. For electric gas lighting or other low resistance circuits, on the other hand, much internal resistance would be, if not absolutely fatal, certainly a positive disadvantage.
Page 2 - It shirts from the positive zinc plate, flows through the fluid to the copper plate, and through the external circuit and back to the zinc plate. The copper strip, whence the current starts on its journey through . the external circuit, is called the positive pole [ + ] and the zinc strip is called the negative pole [ — ]. When the external circuit is broken no current flows, but still the wire connected to the positive pole (copper plate) is called the positive wire, and the wire connected to...
Page 18 - Blue vitriol should be dropped into the jar as it is consumed, care being taken that it goes to the bottom and not on the zinc. The need of the blue vitriol is shown by the fading of the blue color, which should be kept at least as high as the top of the copper, but it should never reach the zinc. There should always be some bluestone crystals in the bottom of the jar. After the battery has been started...
Page 4 - Fig. 7. or cloth may be used to rub them, so as to reach all points of the surface. Where a large quantity is to be amalgamated, the following will be found to be a good method:• Dissolve eight ounces of mercury in a mixture consisting of two pounds of hydrochloric and one pound of nitric acid; when the solution is complete, add three pounds more of hydrochloric acid.
Page 43 - It usually consists of a cylindrical knob of ivory or porcelain capable of moving loosely through a hole in a circular support of porcelain or wood, and which, when pressed, forces a platinum-tipped spring against a metal pin, and so makes electrical contact between the two parts of the interrupted...
Page 39 - Figure 148), is used. The induction coil consists of a cylindrical bobbin having a central iron core surrounded by a short inner or "primary" coil of stout wire, and by an outer "secondary" coil made up of many thousand turns of very fine wire, which is carefully insulated between its different parts.
Page 37 - strength" of a magnet is the "strength" of its poles. The " strength " of a magnet pole must be measured by the magnetic force which it exerts.