In the present paper, we have proceeded to investigate hurricanes and well developed cyclones that pass over the neighbouhood of the British Isles. The following empirical. formula for the pressure distribution is applicable for hurricanes and the circular cyclones where p is pressure at any point, P, Q and m are constants and r is the distance from the centre of cyclone. By using equation (1) we calculated the pressure gradient the gradient wind velocity and the tangential height of the wind to the isobars. We have obtained a new result that the tangential height is the lowest at the centre.
In the present paper, we have ascertained the existence of surface of discontinuity due to the mountain ranges by the observations of temperature, rainfall and wind. At Tôkyô, Osaka, Hirosima, K_??_dyô and other some places in Japan_??_t he heavy rainfalls are generally caused by the local warm front associated with the cyclone. The regional distribution of rainfall associated with a line of discontinuity which runs west and east, that is, from Kyûsyû to Kwantû district, is much on the coast of the Japan sea and less on the side of Pacific coast. This is a result that the northerly wind is force to climb up the mountain side facing to the Japane sea, and then, the upper southwesterly wind is also thereby forced to rise higher.