OBSERVATORIES AND THE DATA OBTAINED. 99 
First SECOND 
PRELIMINARY|PRELIMINARY 
TREMORS. TREMORS. 
REGULAR PRINCIPAL 
eae PERIOD, 


m. . m 
° 8. 
(1) Northcomponent .| .. .. 36 49? 
(2) East component. . 
(5) East component. . 37 
PEVETARE cues. aq” 36 
intervals so 1. 24 







The vibrations of the water make it impossible to determine the phases from the Vasca 
Sismica either at Porto d’Ischia or at Grande Sentinella; at the former distinct waves 
of period about 18 seconds and amplitude 0.6 mm. occur from 14” 04.0" to 14" 18.0". At 
Grande Sentinella, the waves are discernible at 13" 56.0"; a maximum with amplitude 
of nearly 1 mm. is reached at 14” 07.0"; the periods are from 18 to 24 seconds. 
During the strong motion the periods of the vibrations recorded by the Grablowitz 
pendulums are the same as those of the pendulums themselves; namely, 17 seconds at 
Porto d’Ischia and 12 seconds at Grande Sentinella. If we attempt to find the earth- 
amplitudes by using the values of the damping and friction, we find 0.33 mm. or less; but 
it is evident that the regular movement did not continue long enough to allow the pen- 
dulums to take their full amplitudes. 
CAGGIANO (SALERNO), ITALY. 
Osservatorio Meteorologico-Geodinamico. Signor P. Allard, director. 
Lat. 40° 54’ N.; long. 15° 30’ E.; altitude, 831 meters; distance, 92.63° or 10,297 km. ; 
chord, 9,213 km.; direction, N. 30° E. 
The instrument used was an Agamennone seismometrograph, northwest and south- 
west components; mechanical registration with ink on white paper. T,, 6 seconds; 
VY, 12.5; J, 112 meters; M, 200 kg.; L, 8.95 cm. 






SECOND , 
R E 
Aap marae Roe Max. AMPLITUDE, PERIOD, ph ieee 
m. 4&8 m. 8. m. a mm. sec. mm. 
Northwest component . 36 40 56 46 04 10 0.9 22 0.95 
intervals) 24 12 44 18 






At 13" 59.5™ the long waves on the northwest component had an amplitude of 0.4 mm. 
and a period of 32 seconds, corresponding to an earth-amplitude of 1 mm. At 14° 07.3" 
the northwest earth-amplitude was 0.68 mm. The northeast component was not per- 
fectly free and was less sensitive than the northwest, so that the times can not be made 
out reliably; but notwithstanding this it indicated an earth-amplitude of 2.2 mm. at 
14" 04.2; denoting the strongest motion at right angles to direction of propagation. 
The seismogram arrived too late for reproduction. 
TAIHOKU, FORMOSA, JAPAN. 
Meteorological Observatory. H. Kondo, director. 
Lat. 25° 04’ N.; long. 121° 31’ E.; altitude, 10 meters; distance, 92.75° or 10,311 
km.; chord, 9,222 km.; direction, N. 55° W. 
Foundation, clay. 
Seismograms, sheet No. 15. 
The instrument used was an Omori horizontal pendulum, east component; mechanical 
registration on smoked paper. T7',, 17 seconds; V, 10; J, 720 meters; ¢, 1.27; r, 0.13 
