Signalling through space without wires : being a description of the work of Hertz & his successors . ntirely unaccom-panied by static charge or by resultant algebraic electrictransmission, evoke no excitatory response until they are soviolent as to give rise to secondary effects such as heat ormechanical shock. Yet, notwithstanding this inaction, they 18 SIGNALLING WITHOUT WIRES. gradually and slowly exert a paralysing or obstructive actionon the portion of the nerve to which they are applied, so thatthe nerve impulse excited by the feeble just perceptible TJo^nvolts stimulus above is graduall
Signalling through space without wires : being a description of the work of Hertz & his successors . ntirely unaccom-panied by static charge or by resultant algebraic electrictransmission, evoke no excitatory response until they are soviolent as to give rise to secondary effects such as heat ormechanical shock. Yet, notwithstanding this inaction, they 18 SIGNALLING WITHOUT WIRES. gradually and slowly exert a paralysing or obstructive actionon the portion of the nerve to which they are applied, so thatthe nerve impulse excited by the feeble just perceptible TJo^nvolts stimulus above is gradually throttled on its way down tothe muscle, and remains so throttled for a time varying froma few minutes to an hour after the cessation of the violence.[I did not show this experiment at the lecture.] Air Gap and Electroscope charged by Glass Rod and discharged bytJie Wave Impulse from a moderately distant Sphere excited by Coil. Among trigger methods of detecting electric radiation, Ihave spoken of the Zehnder vacuum tubes; another methodis one used by Boltzmann.* A pile of several hundred volts. Fia. 16.—Air gap for Electroscope. Natural size. The bottom plate isconnected to, and represents, the cap of an electroscope; the knob aboveit, mentioned in text, is the polished end of the screw, whose terminalis connected with the case of the instrument or earth. The electroscopebeing charged to the verge of overflow, the impact of weak electric wavescollected by a bit of wire sticking up from the left-hand binding screwprecipitates the collapse of the leaves. is on the verge of charging an electroscope through an air gapjust too wide to break down. Very slight electric surgingsprecipitate the discharge across the gap, and the leavesdiverge. I show this in a modified and simple form. On thecap of an electroscope is placed a highly polished knob orrounded end connected to the sole, and just not touching thecap, or, rather, just not touching a plate connected with thecap (Fig. 16), t
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Keywords: ., bookcentury1900, bookdecade1900, bookidsi, booksubjectelectricity
