Observations of Optical and Chemical Properties of the Water of Lake Kawaguti and Lake Saiko in the Fuji Lake District.

[摘要] In this note are described a device of measuring the transmission of light through lake water, and some r_??_ults of test observations made in Lake Kawaguti and Lake Saiko of the Fuji Lake District toward the end of August, 1935. Beside, in the scheme of our work are inc_??_uded some other physical as well as chemical observations. The transmission apparatus consists of two cylindrical metal vessels which contain an electric lamp and a photo-cell respectively, sealed waterlight and rigidly co_??_nected each other by means of four brass rods having a free space between the windows at the ends of the _??_ylinders. The cell and lamp are connected to a microamme_??_er and to a battery respectively by means of cables so as to enable us to read the photo-cur_??_ent intensity at any moment when the light is switched on, the whole instrument being hung down into the water up to a desired depth. Though the instrument gave incredibly high values of transmission coefficient of water, it is thought to serve for determining the general character of the distribution of turbidity. The observations were confined to the middle part of each lake. In each series of observations an abnormally turbid layer was found at a certain depth which corresponds to the layer of the maximum gradient of temperature. its existence is attribu'ed to the possible invasion of colder shore water creeping under the warmer surface water brought down along the mountain slope after being precipitated. The authors also describe a plan of improvements of the instrument which seems to be necessary in giving more reliable values of transmission coefficients.At the same time, some chemical constituents of water were determined and meteorological effects upon the chemical composition were discussed. There was found no apparent relation between the change, with depth, of the light transmission and that of chemical composition.

[学科分类] 大气科学