OBSERVATORIES AND THE DATA OBTAINED. 101 
(3) Vertical component: 7, 1.8 seconds; V, 120; J, 97 meters; ¢, 1.14; M, 56 kg. 
The records were greatly disturbed by the wind so that the times of arrival of the first 
two phases were entirely lost; the long waves appear at 13" 55.5" on the northwest com- 
ponent. The greatest movement of the earth occurred during the principal part, at M, 
(14" 07.8"), when we find 

AMPLITUDE, PERIOD. EartTH’s AMPLITUDE. 





mm. mm, 
Northwest component . 2.0 1.66 
Northeast component . 0.4 0.30 
Vertical component . . 0.2 0.25 



_ As a possible maximum of the earth-amplitude we have 1.7 mm. During the long 
waves, at 14" 04.7™, the period was 30 seconds, and the earth-amplitude 0.93 mm. The 
letters on the seismogram correspond to times as follows: M,, 14" 04.3"; M,, 14" 07.8"; 
M,, 14° 10.1"; M,, 14° 12.7”. 
CATANIA, SICILY, ITALY. 
R. Osservatorio di Catania ed Etneo. Prof. A. Riccd, director. 
Lat. 37° 30’ N.; long. 15° 05’ E.; altitude, 42 meters; distance, 95.04° or 10,567 km. ; 
chord, 9,396 km.; direction, N. 32° E. 
Foundation, lava. 
Seismograms, sheet No. 13. 
The instrument used was a long vertical pendulum, two horizontal components; 
mechanical registration with ink on white paper. 
(1) Northeast component: 7, 10 seconds; V, 12.5; J, 310 meters; ¢, 1.01; r, 0.4 
mm.; M, 300 kg.; L, 24.9 meters. 
(2) Northwest component: T,, 10 seconds; V, 12.5; J, 310 meters; e, 1.026; r, 0.5 
mm.; M, 300 kg.; L, 24.9 meters. 
First SECOND 
Previmi- | Pretimi- | REGULAR | PRINCIPAL 
NARY NARY WAVES, Part. 
TREMORS. | TREMORS. 
Eartn’s 
AMPLI- 
TUDE, 

™m,. é. ™, 8 m, &. . 8. . . . . mm, 
(1) Northeast component) 26 05 (37 27 | 56 24 45 : 0.72 
(2) Northwest component; 26 05 | 35 23 calms 50 4.0 0.72 
Average 26 05 |36 257} 56 24 48? 
Interval 13 37 | 23 57?) 43 56 20? 





At the times of the maximum on each component the movement is comparatively 
~ small on the other component, so that the total earth-amplitude would not be more than 
about 0.8mm. The northwest component shows signs of friction; this may be the reason 
why it does not bring out the long waves, and why the principal part is of somewhat 
shorter duration than on the northeast component. 
RIO DE JANEIRO, BRAZIL. 
Observatorio de Rio de Janeiro. Dr. H. Morize, director. 
Lat. 22° 54’ S.; long. 43° 10’ W.; altitude, 44 meters; distance, 96.28° or 10,703 
km.; chord, 9,488 km.; direction, 8. 66° E. 
Foundation, decomposed gneiss. 
The instruments used were Bosch-Omori horizontal pendulums, two horizontal com- 
ponents; mechanical registration on smoked paper. M, 15 kg.; V, 15. 
