Abstract
The nature of the mysterious sea fire “Siranui” in Japan have been studied by the present writer. Among the various natures the extraordinary refraction of fishermen's lamplight is the most interesting and this is the essential nature of the Siranui. In the summer of the last year we examined again this phenomenon with a large camera and bright lamps in the Siranui sea. The camera was constructed with a telescope removing its eyeglass. The focal length of its lens was one meter and its plate holder was moved slowly by means of an electric motor and gear-wheels, in the vertical direction or that near horizontal one. As light sources. the head lights of automobiles were used. The lights and thermometers were set on floats respectively. With these apparatus the temperature of the sea water, that of air near the sea surface and the refraction of lights passing through the air were measured accurately, and a result similar to that given in the study of the Siranui was obtained.
