Usually, in analyzing monocoque construction, we use the "effective shear modulus" Ge, which value is smaller than that of G of the material itself. It is said that this effect is explained by the fall in rigidity as the result of the gradual increase in the inclination of stress transmission from 45 degrees in the case of a tension field. Besides this decrease in rigidity, it appears in the stress distribution, or diffusion, in the thin wall and stiffeners construction (Monocoque). The author believes that this fact also eaplains the difference in the solution of twisted box beam from that of St. Venant's, to verify which he performed experimental studies by twisting box beams of various lengths.
He obtained formulae of the tension field theoretically by the energy method, availing himself of the large deflection theory, but owing to the great difficulty of applying these formulae directly to our experimental stndies, he assumed the tension field complete, and elncidated also the relation between stress of field and the deflection of the edge stiffeners.

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The effects of a number of factors on cylinder temperatures were investigated in order to analyse the heat transfer process in an air cooled engine. Tests were made with an air cooled double row radial engine in propeller cooling. Temperature distributions over the entire cylinder were carefully measured, for which purpose 20 thermocouples installed each on both the front and rear cylinders were brought into service.
The results may be summed up as follows!
1) In the case of propeller cooling, the front row temperature distributions have been found to differ from those of the rear.
2) Spark plug gasket temperatures are linearly related to both the highest and average temperatures of cylinder for all operating conditions.
3) When the cooling conditions were kept constant, the polar curves that indicate the temperature distributions in the cylinder, gradually enlarged in similar manner to that as when the air fuel ratio changed from 9 to 15.
4) When the engine operating conditions were kept constant, the values of the average cylinder temperature, minus the cooling air temperature, all gave the same results.
5) When the air fuel ratio was kept constant, the temperature distributions were found to be similar for different revolutions and boost pressures.
6) With very late spark setting, the temperatures of the exhaust side were so high, owing to the high exhaust gas temperature, that the average cylinder temperatures were higher than that of optimum spark setting. With increased spark advance, the cylinder temperatures rose as the result of the increased time during which the cylinder walls were exposed to burned gases.
7) Both cylinder and gas temperatures decreased with increasing compression ratio.
8) Researches on the effect of the particular kind of fuel and spark setting on the cylinder temperatures were made. Although with optimum spark setting, the temperature differences between the 87 and 92 octane fuels were sight, with delayed or increased spark advances, the temperatures of a lean 87 octane fuel were higher than that of 92, with frequent detonations.
9) The center pole temperatures of two kinds of spark plug were measured with the object of determinig their adaptability to various operating conditions.
10) From the heat transfer theory, the following empirical expression was derived for our propeller running.
T_w: Average cylinder heat temperature.
T_a: Colling air temperature.
T_g: Sparkplug center pole temperature.
Constant: 0·275 for our tested engine.

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The author describes monometers, tachometer, automatic balance, six-components balance, and a propeller balance, all of which were designed by him for use in wind tunnel experiments in the simplest way possible and with maximum accuracy.

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