OBSERVATORIES AND THE DATA OBTAINED, 83 
(1) North component: 7, 8.5 seconds; V, 220.6; J, 4,000 meters; e, 3.05; M, 1,100 
ke.; L’, 18.1 meters. 
(2) East component: 7’, 8.5 seconds; V, 241; J, 4,350 meters; ¢, 2.4; M, 1,100 kg.; 
L’/, 18.1 meters. 
SECOND 
Prewvimi- | Reauuar | PrINcIPAL AMPLI- 
NARY WAVES. Part. aia TUDE, 
TREMORS. 
First 
PRELIMINARY 
TREMORS. 
EARTH’sS 
PERIOD. 

Ma 8: Be in. in. mm. 
(1) North component 35 39 . sr 
™. 8. 
644 
(2) East component 35 39 644 
Average... 35 639 
Interval. AS 




Duration, 4.4 hours. At 13" 54™ the long waves of north component had a period of 
about 40 seconds and an amplitude of 10 mm. This gives an amplitude on the north 
component of the earth-movement of about 1mm.; at the same time the east component 
indicates an earth-amplitude of 1.2 mm., and the total may be 1.5mm. At 13" 55™ 
41°, the east earth-amplitude is 1.81 mm. and the combined amplitude is 2.17 mm. At 
13” 57.5" the north earth component is 0.58 and east component 1.55; total 1.65 mm. 
These amplitudes are not entirely trustworthy, because at times the instrument reached 
its limit and the motion was not very regular. At Plauen, a substation of Leipzig, and 
90 km. to the south, the record resembled that at Leipzig. 
The seismogram from Leipzig is reproduced in “Siebenter Bericht der Erdbebenstation 
Leipzig” (Ber. der Math. Phys. Kl. d. Kon. Sachsischen Gesells. d. Wissens. zu Leipzig. 
Bd. LIX, January 14, 1907). A copy of this was forwarded by Dr. Credner, but the seismo- 
gram was overlooked, and therefore is not reproduced in the atlas. 
JENA, GERMANY. 
Sternwarte. Prof. Dr. Rudolph Straubel, director; Dr. Eppenstein, assistant. 
Lat. 50° 56’ N.; long. 11° 35’ E.; altitude, 155 meters; distance, 82.45° or 9,167 km. ; 
chord, 8,396 km.; direction, N. 27° E. 
Foundation, in the valley of the Saale River, on 4 to 5 meters of weathered sandstone, 
underlain by the Bunt sandstone. 
Seismograms, sheet No. 11. 
The instrument used was a Wiechert inverted pendulum, two components; mechanical 
registration on smoked paper. 
(1) North component: 7, 11.6 seconds; V, 160; J, 5,300 meters; ¢, 5.0; M,1,200kg.; 
L’, 33.6 meters. 
(2) East component: 7, 11.6 seconds; V, 180; J, 6,000; ¢«, 5.0; M, 1,200 kg.; 
L’, 33.6 meters. 
First PRELIMINARY | SECOND PRELIMI- | REGULAR PRINCIPAL Max 
TREMORS. NARY TREMORS. WAVES. Part. 
m. 8. m 8 min. min. min. 
(1) North component 24 34 35 09 51.2 56.5 to 07.5 | 55.0 to 59.0 
(2) East component 24 34 35 09 51.2 56.8 58.0 to 00. 
m™m. &. m. 8. 
Average ... 24 34 35 09 51 12 56 39 
Interval . ..- 12 06 22 41 38 44 44 11 






