In the present paper, the writer intends to facilitate the understanding of the phen mena of electric oscillation in the transmission lines. The resonance frequency is deduced from the general equations for an aerial circuit, censisting of parallel lines of uniformly distributed capcity and inductance, connected at its end to the net-works of concentrated inductance and capacity. Neglecting the resistance, the distribution of current and potential along the resonant transmission line is discussed.
In the experiments conducted by the writer on parallel aerial line 538 meters long, be obtained the resonant wave length and experienced that stationary wave is produced in the aerial line by the impressed undamped current of the resonant wave length. The obtained results show the coincidence with the theory.
Wired Radio in high tention transmission line is an applications of the phenomena of electric oscillation in the aerial line and there are two systems in practice. In on system high tension condensers are connected between the carrier telephone apparatus and transmission line; and in the other system resenant parallel lines are stretched on the same tower with the transmission line, The former was described by the writer in "Proceedings of the Institute of Radio Engineers June 1920", and the latter is dessribed this paper. This method is patented by the writer and his cooperates in Japan, Sept. 1920. and it was works out independent of foreign investigations. This study was made at Hiraiso laboratory in 1920. and the further investigations will be published in the near future.

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To prevent the dangerous voltage induced in the telephone and telegraph lines by the accidental ground of the grounled power transmission line, high resistance is used in Japsn for the coonnection of the neutral of the power system to the earth.
The voltage induced in the steady state, however, may be suppressed by the insertion of high resistance between the neutral and the eartb, we do not know as to the transient voltage. This paper describes the oscillographic experiments performed by the authors using the power and telephone line of Inawashiro Hydroelectric Co of about 50km in length. Practically no danger will be produced on the communication line by the insrtion of high resistance between the neutral and the earth.

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The form and the magnitude of impulse voltage and curcen's are studied by means of a cathode ray oscillograph, so that. errors due to the inertia of the moving parts may be obviated.
The impulse generator is of the type in which a D. C. is switched cn to the primary winding of a step up transformer, and a transient high voltage is induced in its secondary. The make and break of the D. C. are repeated by the use of a mercury turbine interrupter.
1. As the effect of the distributed capacities of thrnsformer windings, free oscillations of remarkable magnitude became superimposed upon the logarithmic transients such as are generally expected from simple theories. And hence the peak value of voltage is far different from and much higher than those calculated by Steinmetz and-others. The oscillation is so rapid that it seems likely that the ordintiry oscillographs of electromagnetic or static type would fail to accurately reproduce the phenomena.
2. When condensers are ccnaeetd d across the secondary terminals, the free oscillations undergo marked interesting changes.
It is finally pointed out that there are considerable difficulties in applying the cathode ray oscillograph to the measurements of extra high voltages.

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