(22 REPORT OF THE CALIFORNIA EARTHQUAKE COMMISSION. 
The instruments used were Bosch-Omori horizontal pendulums, two horizontal com- 
ponents; mechanical registration on smoked paper. 
(1) North component: 7, 20 seconds; V, 10; J, 1,000 meters; e, 1.066; r, 3.25 mm. ; 
Mill kro. 
(2) East component: 7'y, 21 seconds; V, 10; J, 1,100 meters; ¢,1.0; 7, 2.6 mm.; 
M, 11kg.; DL, 75 cm. 

First PRELIMINARY | SECOND PRELIMINARY | REGULAR gre eee Max. AMPLITUDE. 








TREMORS. TREMORS. WAVES. 
eo | 
m  & m. & min. min. mM. “8. mm, 
(1) North component 21 45 30 24 40? 43 to 50? | 48 50 24 
(2) East component 21 54 29 50 39? uvebm roar aay) pO Ke) 30 
Average .. . 21 50 30 07 39.5? 
Interval . . % Om 22 17. 39 Zan 




Duration, north, 2 hours; east, 2.5 hours. The periods of the waves coincide with 
periods of the pendulums and the strong motion lasted too short a time to enable an esti- 
mate of the earth’s motion to be made. There seems to have been a certain amount of 
separation of the north and east components of the waves, as the strong motion of each 
occurs when that of the other is much reduced. The regular waves do not appear very 
definitely. 
TRINIDAD, BRITISH WEST INDIES.' 
St. Clair Experiment Station of the Botanical Gardens. J. H. Hart, F. L. 8., super- 
intendent. 
Lat. 10° 40’ N.; long. 61° 30’ W.; altitude, 20.5 meters; distance, 60.94° or 6,774 
km.; chord, 6,460 km.; direction, 8. 80° E. 
Foundation, 2 meters of concrete laid on sands and clays. 
The instrument used was a Milne horizontal pendulum, east component; photographic 
registration. 7,18 seconds; V, 6.1; J, 490 meters; angular displacement, 1 mm. = 0.5”; 
M, 255 gm.; L, 15.6 cm. 
Preliminary tremors, 11"; regular waves, 42"; maximum, 53”; amplitude, 10”. 
Interval for regular waves, 29.5 minutes. 
The record of the commencement is evidently erroneous. The time of arrival of the 
regular waves at 42" may be fairly correct. Duration 3.2 hours. 
APIA, SAMOA.’ 
Observatorium der Kgl. Gesellschaft der Wissenschaften in Gottingen. Dr. F. Linke, 
director. 
Lat. 18° 48’ 8.; long. 171° 46’ W.; distance, 69.20° or 7,694 km.; chord, 7,235 km.; 
direction, S. 52° W. 
The instrument used was a Wiechert inverted pendulum (1,000 kg.), two horizontal 
components; mechanical registration on smoked paper. 
First preliminary tremors, 23" 22°; interval, 10” 54°. 
Second preliminary tremors, 32™ 24°; interval, 19” 56°. 

1 The data were obtained from Circular 14 of the Seismological Committee of the B. A. A. S. 
2 Information obtained from Wiechert and Zoeppritz, ‘‘ Ueber Erdbebenwellen”’; Nach. Kgl. Gesell. 
Wissen. Gottingen, Math.-Phys. KI., 1907. 
