In the present paper, the author reviews some of the tests made on the electro-culture especially on the experiments using artificial light, which have been performed at different universities and laboratories abroad.
He briefly discusses the effect of light rays upon the growth of plant and gives explanation relating to a few of the tests carried out by using an electric lamp as light source

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This paper describes a method employed by the authors, to find quite easily and quickly the natural oscillation frequency of high tension testing transforaners, and also some results obtained by this method. The free oscillation produced in the secondary winding is directly observed by Braun tube, applying repeated voltage impulses into the primary winding.
A testing transformer 100k. V. A., 250, 000 volts was tested and it was found that the series resonance frequency is about 700 cycles while the parallel resonance frequency about 140 cycles.
A variable condenser of known capacity was connected across the secondary winding, under various conditions of primary and secondary windings and it was confirmed that the square of the natural oscillation period increases linearly by the increase of the capacity (Fig. 6). The self capacity of the secondary winding was thus found as shown in table 1.
The effect of resistance in the primary circuit upon the natural frequency was invcstigated experimentally and was explained by theoretical considera tion.
The natural frequency of a telephone receiver was also measured by our method.
This paper contains the following items. [1] Jntroduction [2] Method of measurement [3] Construction of transformer under test [4] Experimental results [5] Theoretical consideration [6] Measurement of natural frequency of telephone receiver [7] Accuracy and limit of applicability of this method.

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The surface creepage phenomena have been observed by many investigatois. The author describes, in this paper, the experimental research about the surface creepage phenomena occuring in atmosphere of low pressure.
The source of potential is an alternating Potential derived from a hightension testing transformer. The pressure in the exprtimental chamber was varied one atmospheric to about 5mm Hg.
The materials over which the surface ereepage was produced were porcelain, glass mica, ebonite and bakelite.
In our experiments, a notable feature was observed, that is, the creepage along the surface of solid insulator takes place only at the pressure ranging between one atmospheric and a certain limiting pressure. Under the pressure lower than this limiting value, the discharge does no longer stick to the surface but goes into the air space away from the solid.
The above phenomenon may be explained from the relation of the dielectric strength of the air space and that of the boundary surface between the air and the solid.
In atmospheric, pressure the strength of the air space is greater than that of the path along the boundary, and therefore the discharge creeps along the surface of the dielectric. When the pressure is reduced, the strength of the boundary surface decreases gradually, but, at the same time, the strenoth of the air decreases much more rapidly and finally at a limiting pressure the strengths of the parallel paths become equal and after that the discharge becomes casier to take. place through the air space.
The surface spark over potential was then studied in an atmosphere at the pressure ranging between one atmospheric and the limi ing pressure.
"The surface spark over potential can be expressed as a function of the product of the surface creepage length and the pressure."
The above proposition is considered to constitute a new law about the surface creepage phenomena and is comparable to Paschen's law for the discharge in the air.
The break down potential at the pressure lower than the limiting pressure can naturally be determined by Paschen's law, since the discharge goes through the air space only, as if there were no dielectric.

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A method of measuring acoustic impedance is described which is independent of the instrument constants. A system of acoustic tubes, a sound generator of measurable vibratory velocity and an acoustic pressure meter of Gerlach's principle are required.
A general tube system considered is shown in Fig. 3 (A), where A, D, ZR are the sound generator, pressure meter and the acoustic load to be measured. The value of ZR is given by equation (29), where xA and FD are respectively the vibratory velocity at A and the acoustic total pressure at D and those with a suffix ∞ correspond to the values when ZR=∞. And xA is proportional to the motional impedance of the sound generator and FD to the balancing current of the pressure meter. Thus these two are measurable and therefore ZR. For actual measurements, however, special cases such as shown in Fig. 4. are sufficient.
Moreover, a method of measuring mechanical impedance of a diaphragm and also those for acoustic constants of cloth or similar materials are added.

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The current-voltage curves on the surface of ebonite plate, transformer oil, and ebonite plate immersel in oil are measured by the same method usel in the previous paper.
In the next place a method of obtaining a surface charge figure is given. The fine powder of mixture of red lead and sulphur or resin and load acetate is sprinkled over the surface of ebonite plate after an application of voltage. In other words, the voltage is applied for a few seconds, and then it is taken off, after this process the fine powder sprinkled over the surface of the ebonite plate. The figure is not due to the intensity of electric field, but to residual charge on the ebonite plate. We can not obtain the surface charge figure by usin glass plate, porcelain, paraffin or mica plate, but ebonite, resin or sealing wax.
Many surface charge figures are obtained using various kinds of electrodes in case of A.C. and D.C. voltage.
In the next place, actual experimental results of surface residual charge measured by means of ballistic galvanometer and the surface charge figures are described.
In the last parts of the paper, the surface charge figures by impulse voltage are described. These figures can be used to measure polarity and max. value of the impulse voltage, i.e. in place of a klydonograph. Of course in this case the fine powder is sprinkled over the ebonite plate after application of impulse voltage.

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The present paper first descibes general characteristics of the supervisory control systems and classifies those systems developed in Europe and America at present according to the operation and then gives general requirements for the supervisory control system. The paper also gives a general deacription of several existing systems such as Selector, Distributor, Audible, Code Visual, Synchronous Visual, Synchronous Selector and systems using carrier current etc., and some details concerning a system developed by the author which uses automatic telephone relays and rotary switches and in which the selection is made by the mean of the mumber of impulses or their combination. The author's system is applicable to a very large number of power apparatuses scattered or centralized, and is characterized by the particular feature of impulse sending.
In the last part of the paper, some comments are made on the Supervisory control systems described and their relation to tele-metering is also tonched upon.

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