. Journal of electricity, power, and gas . oupling is employed. Poulsen has transmitted good, clear, articulatespeech over the 180 miles between Esbjerg andLyngby, Denmark. Majorana claims to have done 312miles over water with a specially constructed micro-phone of his own devising. More recently I have car-ried on successfully two way working between Stock-Ion and Sacramento, California, a distance of 50 milesover land, and while_ working between these two sta-tions was heard by St. Helena and Palo Alto, distancesof 75 and 85 miles respectively. There is no doubt that wireless working giveste
. Journal of electricity, power, and gas . oupling is employed. Poulsen has transmitted good, clear, articulatespeech over the 180 miles between Esbjerg andLyngby, Denmark. Majorana claims to have done 312miles over water with a specially constructed micro-phone of his own devising. More recently I have car-ried on successfully two way working between Stock-Ion and Sacramento, California, a distance of 50 milesover land, and while_ working between these two sta-tions was heard by St. Helena and Palo Alto, distancesof 75 and 85 miles respectively. There is no doubt that wireless working givestelephony of a higher grade than wire working. Thereis absolutely no noise in the receiver until spokenwords are heard. To one who has talked over longdistance wire lines with considerable induction thisfeature readily appeals. Low resistance receivers areused and expensive high resistance receivers are notnecessary. Wireless Telegraphy. With the Poulsen generator of continuous wavesit is possible to telegraph at hand speed, i, e., 25 words. Fig. 4, Rapid Receiver. April 2, 19101 JOURNAL OF ELECTRICITY, POWER AND GAS 297 per minute in many ways. J©! example, it is possibleto signal by : (a) Short circuiting a resistance in the generatorcircuit. (b) Short circuiting a resistance in the antennacircuit. (e) Making and breaking the arc. (d) Altering the length of the arc. (e) Altering the strength of the transverse mag-netic field. (f) Altering the flow of gas through the arc. In practice Poulsen short circuits a turn or two ofthe sending inductance by means of an ordinary Morsesending key. The absence of the spark permits of theuse of an ordinary key when telegraphing 2000 miles,for the current is even then quite small. For receiving, Poulsen uses the ticker which hasthe great advantage of not being receptive to ordinarydamped wave signals. The tuning possible with the Poulsen arrange-ment for telegraphy is extremel} close. One-half toone per cent change in the capacity of the reso
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Keywords: ., bookcentury1800, bookdecade1890, bookidjo, booksubjectelectricity
