. An elementary manual of radiotelegraphy and radiotelephony for students and operators . form of heat in the arcitself. The single arc works well up to about 10 amperes and 440volts, but when it is desired to obtain more energy in an oscil-latory circuit, then it is better to employ a number of arcs joinedin series rather than attempt to put more cunent through a singlearc. An easily managed form of arc generator devised by theAuthor is as follows: —On a metal pot or vessel is placed a metallid (see Fig. 19). This lid has in it certain holes bushed withebonite through which pass steel rods. E
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . form of heat in the arcitself. The single arc works well up to about 10 amperes and 440volts, but when it is desired to obtain more energy in an oscil-latory circuit, then it is better to employ a number of arcs joinedin series rather than attempt to put more cunent through a singlearc. An easily managed form of arc generator devised by theAuthor is as follows: —On a metal pot or vessel is placed a metallid (see Fig. 19). This lid has in it certain holes bushed withebonite through which pass steel rods. Each of these carries at io8 RADIOTELEGRAPHY its lower end a coppea* cylinder open at tlie bottom and closed atthe top except for a few small holes. The lid also carries asliding tube, at the bottom of which is fixed a plate. This platehas fixed to it certain insulated holders, in each of which is alength of arc-lamp carbon. The copper tubes fit over thesecarbons like extinguishers over a candle. Each steel rod carryingthe copper tubes is adjustable independently for height, so as to. Fig. 19.—Section of Fleming arc generator of undampedoscillations. make the copper extinguisher just rest on the carbon. Then, bymeans of a screw, the bottom plate can be lowered and make aspace of equal length between the tops of all the carbons and theunder side of the tops of all the copper cylinders. By means ofinsulated wires each copper hat is joined to the carbon of thenext pair. If then a voltage is applied we can strike an electricarc between the top of each carbon and the underneath side of itscovering copper hat, and all these arcs will be in series. Themetal vessel is filled about half full of a heavy mineral oil so thateach carbon is immersed in oil up to within an inch of its top andthe bottom edge of each copper cylinder is below the level of theoil. The arc soon heats the copper cylinders, and this heat evapo-rates the oil and fills the closed space in which the arc is burning I
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
