Sketches of the clouds in the whole sky at Toyohara were made at 10h. and 14h. every day from Nov. 1932 to Dec. 1933 by the members of the Toyohara Magnetic Observatory. The author of the present paper investigated statistically the distribution of cloud amount in every part of the sky using these sketches. The annual and seasonal distribution, the distribution for 10h. and 14h., for every case of lower cloud directions, etc. were illustrated by figures. Generally the cloud amount is great near the horizon or mountain-ranges and small near the zenith, but the directional difference near the horizon and the azimuthal displacement of least cloud amount area is seen for respective eases. The difference between 10h. and 14h. is large over the area of the town of Toyohara. This may be caused by the local ascending current of thermal origin. The least cloud amount area near the zenith displaces to leeward side for every four cloud directions. This may be the effect of the local ascending and descending current caused by the greater resistance of the town for the motion of air.
In their recent paper on land and sea breezes, Dr. Kobayasi and Dr. Sasaki treated a theory on land and sea breezes in eminent manners. In the present paper, however, 1 have discussed the same problem without ignoring the factors due to the eddying motion. And the following results were obtained:- 1° Alternation of land and sea breezes as well as wind velocities and distribution of land and sea breezes. The velocity of land and sea breezes attained maximum at the seashore and is 7_??_8m/sec, at most. 2° The amplitude of the diurnal component of the barometric pressure variation is very large in the extensive land area, and very small on the sea. The difference of the variations at such two stations becomes 0.3_??_0.4mm Hg. approximately. 3° The approximate values for the coefficient of eddy diffusivity and the coefficient of eddy viscosity associated with land and sea breezes are concluded as about 105_??_106 C. G. S.
In this paper and the subsequent papers it is assumed that the ionisation of the atmosphere is merely caused by the radiation from the sun. Assuming that the number of pairs of ions produced by the radiation per cubic cm and per second is proportional to the loss of energy of radiation, we meet with an integral but this is not integrable as it is reduced to the form dr. Hence the author tried to integrate this by the graphical method and obtained some results concerning the height of maximum ionisation and the relative number of pairs of ions. The height of maximum ionisation is minimum when the radiation is perpendicular to the horizon and it increases slowly as the inclination of radiation to the horizon deceases. The shape of the curve of the relative number of pairs of ions is almost the same as that of the perpendicular radiation if we consider only the side of the earth facing the sun, hence approximately Pedersen's equation is able to be used there.
The seasonal fluctuation of phytoplankton was observed quantitatively during Dec., 1932 and January, 1934 at St. Futakotamagawa. Diatom was the most predominant species in phytoplankton and appeared abundant'y in the both seasons of winter and spring. The maximum occurrence fell on 21, Dec., 1932, counting 3, 230 per litre and Melosira varians and Synedra spp. were representatives in the diatom. The vertical distribution of marine plankton was examined in the water of Rokugobasi with 7m. in depth.
This is a short report of the measurement of radium emanation in a spring at “Sugi-no-midu”, Tukuba. The apparatus used is an ordinary electrometer with ionisation chamber, made in the manufactory of the Central Meteorological Observatory. It is known from the results obtained that the amount of the radium emanation in this spring varies with the air-pressure.