In the previous paper, the behavior of a slurry tank was expressed by a difference differential equation. Thus, the instability of the oscillation of the concentration of the slurry delivered from the tank was explained.
In the present paper, the author discusses how to make the concentration oscillation stable. It would be achieved by introducing a servo-mechanism feeding the slurry concentration back to the pulp supply rate. Unfortunately, the continuous measurement of the slurry concentration is very difficult, if not impossible.
In order to avoid this difficulty, the author has analyzed the dynamic performance of the whole system from the slurry tank to the slurry press. It has revealed that the pressure of the surge tank depends upon the concentration of the slurry delivered from the slurry tank. The pressure of the surge tank is easily detected continuously. The rate of the pulp supply to the slurry tank is regulated through a servo-mechanism actuated by the pressure of the surge tank.
The characteristic equation of the whole system, including the servo, is derived and transformed into a form suitable for applying the Satche's method. Hence, the whole system can easily be stabilized, even if the pure delay is longer than the transportation lag of the slurry tank.
The feedback control not only stabilizes the system, but also ameliorates the frequency response of the whole system.

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An investigation was made to survey the actual noise level generated by a power loom, devise some method to reduce the noise level on the power loom and explore the possibility of controlling the noise generated by looms in a factory.
A power loom was placed in a room, 494M³ in volume, of the workshop attached to our university. The mean value of six room-constants obtained in various octaves band measured 152m². The noise level and the octave band sound pressure level were measured with a sound level meter, an octave band filter and a level meter. Equal-level contours of the noise level and the sound pressure level were drawn with these instruments. The noise level at a height of 150cm reached a maximum of 90phons.
The noise within about 2 meters from the loom was louder on the diagonal line, but at 2 meters or a longer distance from the loom it was regarded as a point source. The frequency characteristic of the sound pressure level showed a peak value in the 1600-3200c/s band. Sound power in the band was 11 milliwatts.
A piece of gum was stuck on the surface of the stopper and a spring was replaced with a suitable one to reduce impulsive. Then the noise made by the picking mechanism decreased by 4-5dB in a high-frequency range.
After the gearing was insulated with a cover, the noise radiated by the gearing in the driving part decreased by 4-8dB in a middle and a high-frequency range. This indicates that the noise generated by a power loom can be reduced considerably by a complete adjustment of the loom and by insulating the sound source.

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No study of color effect is complete unless it deals with at least three aspects: physics, physiology and psychology. This article covers only a phase of the author's 40-year study of color effect, but it goes into a problem not covered in the Universal Book of Color Science. The highlights of this article are:
1) The author has devised a formula for producing multiple colors out of two with a special instrument called Muto Chrome.
2) He has been able to establish physiologically that a colorless state looks colored.
3) He has completed a quantative analysis of a complementary after-image.
4) He has devised a method of more exact and more rapid color-matching.

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