A study was carried out to clarify the effect of specimen-volume upon the tensile strength of snow. For the purpose, unconfined tensile strength of snow was measured by means of apparatus for uniaxial tensile experiment. Specimens used were fine-grained old snow of density ranging from 340 to 360 kg·m^-3. The test-temperature was -10°C. Volumes of cylindrical specimens for the tests were prepared to the following four specifications : 2.4×10^-4, 4.2×10^-4, 1.1×10^-3 and 2.9×10^-3m³, respectively. Ratio of height to diameter of the specimen was 2.5.
It was found, in the experimental results, that the relations between the strength and the volume were as follows : In the case of brittle fracture occurring (when the strain rate was 5.3×10^-4 s^-1),
S= (3.48×10⁴) ·V^-0.096
and in another case of ductile fracture occurring (when the strain rate was 2.2×10^-5s^-1),
S= (5.32×10⁴) ·V^-0.106
where, S is strength (N·m^-2) and V is specimen-volume (m³). The relations indicated that the change in strength with volume was only about 20% in the range of volumes used in the experiments, although the volume increased up to about 12 times.
In previous experiments, scatter in data of tensile strength was about 2 orders of magnitude. From the present results, the reasons could be attributed to damage caused in forming the specimen, to differences of experimental methods, and to the snow qualities used for tests rather than to the effect of specimen-volume.

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A new method of power generation was designed by applying the principle of thermosiphon.
An evaporator and a condenser were connected by two pipes. Air was evacuated from the device, and then freon as a volatile working substance was poured into the evaporator.
The boiled working substance climbed to the condenser through a pipe, and liquefied there. Power was generated by the downward flow of liquid through another pipe.
Experiments were carried out on the thermo and kinetic characteristics of working substances by the use of a thermo-siphon made of glass. To demonstrate the principle of the power generation system, a thermo-siphon device with 15 m head of drop was tested.

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We examined the relationship between snow cover and steel roof sheet used in a heavy snow-fall district. There are several parameters characterizing the dynamic property of snow sliding on steel roof sheet, including shear bonding strength, slip starting temperature, and static and dynamic friction coefficients of snow on the roofs. We have measured these parameters in indoor experiments, and observed snow sliding on roofs in outdoor experiments. In the indoor experiment the shear bonding strength, the slip starting temperature and the static and dynamic coefficients of ice sliding on the steel roof sheets were estimated, and the dynamic properties of the snow sliding on the roofs with batten seams were evaluated in outdoor experiments during the period of winter. A comparison of results between indoor and outdoor experiments is made in this report.

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