The vehemence of migration and the increase in population are very remarkable in Hiroshima, one of the biggest local cities in Japan. The writer has investigated the movement of the population of this city on June 3, 1954. The results are as follows.
1) The migrating population is about 10% of the whole population of this city, and the number of immigrants is greater than the number of emigrants, and migration of the male is more copious than of the female, and the egress and regress because of vocational engagement is more voluminous than that of students. 2) The sphere of the migration is considered, with prefectural units at large in view, to form a circular area with Hiroshima Prefecture as its center; and with Hiroshima City as its center, when the compass of consideration is limited only to Hiroshima Prefecture, which shows that the sphere is decided within short time distance. The area of migration is wider either with immigrants (Fig. 2), men, or with employees than with either emigrants (Fig. 1), women, or students respectively; and decrease is more distinctly witnessed in the wider spheres, in the rate of the migration according as the observation passes from the center to the outermost parts, than in the narrower ones. 3) If the egress and regress in and out of Hiroshima City is examined with the wards in view, the area of migration forms a circle with the ward of Motomachi as its center (Fig, 4), and the rate of the migrationin the center is three or four times as high as that of the outer area, and the rates of emigrants and immigrants in the areas other than the wards of Aozaki and Ijima have inverse correlation, distributed in rectilinear line (Fig. 3). 4) With respect to the hours of migration, statistical curves show 2 peaks and 2 depressions: The former being between 7 and 8 A.M. and between 5 and 6 P.M. while the latter at midnight and between noon and 3 P.M.. The maximum in the rate of migration in the morning is caused chiefly by the increase in influx and the minimum in the afternoon by the decrease in influx, while the maximum in the afternoon is caused by the increase in outflow and the minimum at midnight by the decrease in outflow.
