part 3] THE ITALIAN EARTHQUAKE OF AUGUST 1895. 233 



defined centre of maximum intensity, round which isoseists can be 

 drawn at increasing distances. Such a centre might possibly be 

 recognized at Sestola (44° 14' lat. N., 10° 45' long. E.), where* the 

 fall of small fragments of plaster is recorded; this might bring 

 it into the V° Mercalli, but only very doubtfully. Against the 

 recognition of a centre of maximum intensity, where the shock 

 would be severe enough to attract general attention, must be put 

 the fact that it is especially recorded that the shock was not felt 

 at the observatory on Monte Cimone. This observatory lies about 

 5 miles from Sestola and in a straight line between that place and 

 Fiumalbo (44° 11' lat. N., 10° 39' long. E.), which lies about 

 2 miles farther on, and at which the intensity was about the same 

 as at Sestola. Taking the other localities, it is found that at 

 nearly all a distinctly lower intensity is indicated ; but scattered 

 among them are places where the reports would indicate at 

 least IV°, and some of these are on the extreme limits of the area 

 covered by the reports. At Ala (45° 41' lat. N., 11° 0' long. E.) 

 and Valli di Signori (45° 44' lat. N., 11° 15' long. E.) on the 

 north, at Rettinella (45° 3' lat. K, 12° 9' long. E.) on the east, 

 and at Pontedera (43° 40' lat. K, 10° 38' long. E.) on the south, 

 all localities from beyond which no reports were received, an 

 intensity of not less than 1V° is indicated, though to other places 

 nearer the centre of the seismic area a greater intensity than 11° 

 or IIP M. cannot be assigned. 



The sound phenomenon gives no better indication of a distinct 

 epicentral area, for, although reports are more numerous in the 

 region between Florence, Bologna, and Carrara, the sound was 

 recorded at scattered places up to the extreme limits of the seismic 

 area, as at Erba (45° 48' lat. N., 9° 13' long. E.), Valli di Signori, 

 Argenta (44° 36' lat. N., 11° 50' long. E.), Rotta (43° 39' lat. N., 

 10° 41' long. E.), and Lari (43° 34' lat. N., 10° 35' long. E.). 



The presence of a noticeable vertical component of the motion 

 (sussultorio) is generally confined to the central area, but the 

 attempt to make use of this proved as little conclusive as the 

 distribution of intensity and sound, for the vertical movement was 

 reported from localities at the extreme limits of the seismic area, 

 as at Erba, Castelletto di Brenzona (45° 41' lat. N., 10° 45' long. 

 E.), Argenta, and Lari. 



The close clustering of reports from the southern portion of 

 this area, lying in the region west of Florence and Bologna, is 

 suggestive of an epicentral area of greater intensity of shocks ; but 

 this might Avell be attributed to the fact that this is a region of 

 comparative wealth and ancient culture, where earthquakes have 

 long been a subject of study, and where the number of potential 

 observers and recorders would be greater than in the region on the 

 north, from which no reports were received, until we come to the 

 southern edge of the Alps. It may be that the peculiar distri- 

 bution of the reports, and the absence of any records from 



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