The dispersion data in neutral stability condition were picked out of a series of lowlevel tracer experiments conducted in several urban areas, and were analyzed on the basis of Gaussian plume model. Dispersion parameters calculated from the tracer data were related to several readily measured or derived meteorological data. The results were compared with those of previous dispersion experiments conducted in urban areas.
Under neutral stability condition the vertical standard deviation of concentration correspond to C to D stability classes of the Pasquill-Gifford curves. On the other hand, the crosswind standard deviation of concentration scattered between A and D-E stability classes.

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With the turn of the 1970's, the seasonal variation of Japanese mortality, early infant mortality in particular, has undergone conspicuous changes as reported previously. The present report presents what changes the UK and the USA also have shown in total mortality in comparison with Japan, and what might well be responsible for the different changes in recent deaths in the three advanced countries.
In total mortality, the UK shows predominant concentration in the cold months, while the USA has come to show such moderateness as to be called desceasonality i. e. a seasonal variation pattern nearly equal to a straight line. Japan herself stands in an intermediate position with a high peak in winter and a small hill in summer. In cerebrovscular mortality, deaths are considerably concentrated in winter in Japan and the UK but conspicuously moderate as a whole in the USA. In infant mortality, signs of deseasonality are increasing in the USA and Japan, but there are noteworthy differences between the two nations: a bimodal curve is seen in Japan whereas ups in January-February and in April-June and a trough from July to September are witnessed in the USA seasonal variation pattern.
The marked lowering and the increasing deseasonality of mortality in recent years in Japan are ascribed in the final analysis to the high-rate industrial growth and the subsequent urbanization of Japanese society with better living conditions and improved medical services. As for the UK, sanitary conditions had surprisingly improved as early as the middle of the nineteenth century and the representative seasonal variation pattern came to the fore earliest in the world and remained stabilized for a long span of time, and in the 1970's, no marked changes came to appear as compared with the increasing deseasonality in the USA and the mounting signs of deseasonality in Japan hitherto regarded as 25-30 years behind the USA. The USA is a vast country including high latihidpg and qnhi-rnniral areas and calls for regional analysis: in the southern states generally less advanced than other industrial areas, deaths, infant mortality in particular, are surprisingly concentrated in the cold months in contrast to the general deseasonal pattern in many northern states and remain quite unchanged in the 1960's and 1970's.
An international comparison of the seasonal disease calendars finally reveals that Japan in the 1970's shows noteworthy changes compared with the 1930's and 1950's, while no such noticeable changes are seen in the UK and the USA.

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The relation between the tectonic st r e ss fields in focal regions and stresses released by earthquakes is discussed on the basis of the idea by one of the authors. That is, in cases where earthquakes can be considered brittle fractures of rocks in the crust, the directions of P and T axes in the focal mechanism solutions of earthquakes make an angle of (45-θ)° with the maximum and minimum principal tectonic stress axes respectively. This idea is applied to the Matsushiro earthquake swarm and the following are the points clarified:
1) Earthquakes whose P axes deviate counterclockwise from the E-W direction correspondto the so-called Matsushiro earthquake fault (the fault A) and faults (A_i(i=1,2,.... )) parallel to the fault A. On the other hand, earthquakes whose P axes deviate clockwise from the E-W direction correspond to the fault B which is conjugate to the fault A. (There may be other faults (B_i (i=1,2,.... )) parallel to the fault B.)
2) In the first period (August,1965∼February,1966), only the fault B was active. In the second period (March-July,1966), the fault A began to be very active, and the fault B was not so active as the fault A. In the third period (August∼December,1966)not only the faults A and A_i (i=1,2,.... ) but also the faults B and B_i (i=1,2,.... )were active. In the fourth period (January,1967∼), the fault A andthe part of the fault B near the fault A were inactive, andthe faults A_i (i=1,2,.... ), B (excluding the above mentioned part) and B_i (i=1,2,.... ) continued to be active but with decreased activities.

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For the purpose of observing crustal deformations by use of a geodimeter, nine base lines were established around the volcano Sakurajima (Fig.1). The instrument used for the present observations is the AGA Geodimeter 6BL. The measurements of distances for the base lines were made at an interval of about three months from January 1975 to March 1976.
Observed distances and linear strains estimated on the basis of the first observations are shown for respective base lines in Table 2 and Fig.5.
The volcano Sakurajima has continued its eruption activity for the recent twenty years. During the period of the observations, about two hundred eruptions took place at the Minamidake Crater, as is shown in the middle figure of Fig.6, which indicates the monthly frequencies of eruptions. Especially, activities in March and November,1975, were relatively high.
It is noticed, from Table 2 and Fig.5, that changes of lengths of the base lines were not remarkable during the observation period, excepting those for some base lines.
The changes of distances with time for the three base lines (1-10,8-9 and 2-3), which are located in the west and the north of Sakurajima Island, were relatively large, showing a similar tendency. Moreover, the patterns of fluctuations correlated fairly well with that of the activity of the volcano, as the extensions and contractions respectively corresponding to high and low volcanic activities (Fig.6).

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The seismic wave trains of north-south, east-west and vertical components have been processed through the band-pass filter of adequate frequency range, and digitized during one or two minutes before and after the initial P phase.
Effects of average values included in seismic waves are eliminated by means of subtraction of mean noise amplitude during the one minute preceding the initial P phase from the original record.
The operational circuit executes digital arithmetic of the following equations twenty or thirty sedonds preceding P wave.

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