84 REPORT OF THE CALIFORNIA EARTHQUAKE COMMISSION. 
Duration, 5.6 hours. From 54 to 56", during the long waves the earth’s amplitudes 
were the largest, being 2.6 mm. for the north and 1.9 mm. for the east component, a 
possible total of 3.2mm. At about 59” the indicated earth’s amplitudes are 2.0 mm. 
and 1.5 mm. for north and east components, respectively, and with a possible total of 
2.5mm.; but this is undoubtedly too small, as the instruments reached the stops. 
STRASSBURG, GERMANY. 
Kais. Hauptstation fiir Erdbebenforschung. Prof. Dr. G. Gerland, director; Dr. E. 
Rudolph, assistant. 
Lat. 48° 35’ N.; long. 7° 46’ E.; altitude, 135 meters; distance, 82.91° or 9,218 km. ; 
chord, 8,434 km.; direction, N. 30° E. 
Foundation, compact alluvial gravel. 
Seismograms, sheet No. 14. 
The instruments used were: 
Rebeur-Ehlert triple pendulums, No. 2, two components; photographic registration.’ 
(1) N. 30° E. component; (2) E. component; 7’), 10 seconds; V, 45; J, 1,120 meters. 
(3) Omori horizontal pendulum, east component. 
Vicentini microseismograph, three components; mechanical registration on smoked 
paper. 
(4) North and (5) east components. (6) Vertical component; V, 85; no damping and 
very slight friction. 
(7) Schmidt trifilargravimeter. 



























First SECOND 
R A - 
gern pi rien CS aber he Ln 
moe ‘6. ht 2 min, min m 8. mm. sec. 
(1) N.30°E.component| 24 52 35 18 | 51.2? 58.0 |02 39| 16.5 16 
™m. 8. 
(2) East component 25 06 35 28 46 13 oe oe OLMELY 7.0 20 
(3) East component 24 51 35 17 46 36 Nee = Oe AAs 4.4 12 
(4) North component . ae aes i.¥ RA 48 pees | Ol R25 2.0 22 
(5) East component 24 53 35 18 46 05 eee OZEeao 2.0 18 
(6) Vertical compent 25 12 tives 52 sons; 26 0.3 14 
(7) Vertical component 24 43 plas 50 31 02 31 1.3 16 
Average : 24 57 35 20 
Interval 12 29 22 52 


Duration, Rebeur, 2.5 to 8.5 hours; Omori, Vicentini, Schmidt, 1 to 2 hours. The 
possible maximum earth-amplitude is about 0.75 mm., according to the record of the 
Rebeur-Ehlert instrument. 
The times, amplitudes, and periods are taken from the ‘‘ Wéchentliches Erdbebenbericht 
der Kais. Hauptstation fiir Erdbebenforschung zur Strassburg,’”’ with the exception of 
the long waves, principal part and maximum of (1), which were obtained from the seismo- 
gram. It is evident that the various times under regular waves do not refer to the 
same phase. 
MOSCOW, RUSSIA. 
Imperial University. Dr. Ernest Leyst, in charge of seismographs. 
Lat. 55° 45’ N.; long. 37° 34’ E.; distance, 84.72° or 9,419 km.; chord, 8,584 km.; 
direction, N. 11° E. 
Foundation, sand. 


The constants of these instruments are taken from the text accompanying “Seismogramme de 
nordpazifischen und sudamerikanischen Erdbebens am 16 August, 1906,’ a publication of the Inter- 
national Seismological Association. They probably also apply to April 18, 1906. 
