154 



>1U. II. I). OLDIIAM OX THE PROPAGATION OF 



horizontal pendulu commenced to oscillate at 17 1 ' 58'"; no marked maximum ; end 

 18 h 10. 



Rome. Sismom. setter. At 17 1 ' 45"' 50 s 5" the seismograph was disturbed ; tilt- 

 disturbance decreased, but became once more recognisable at 52'". 



Edinburgh. 18 h 2'" to 18 h 12 slight disturbance on bifilar pendulum. 



Sfiide. 17 h 59 58 s commencement of disturbance, lasting 38'". Preliminary 

 tremors lasted 8 m . 



Summarising these times we get the following, the times being tabulated in minutes 

 after 17 h : 



The maximum at Shide is put at 8 after the commencement, the recorded duration 

 of the preliminary tremors. 



The time of commencement of slight oscillations on the grande sismometrografo at 

 the Rocca di Papa is not included, as it falls intermediate between the times of the 

 first and second phases, and cannot be recognised as a distinct phase on any 

 other instrument. 



The time of commencement at Nicolaiew, as compared with other places, is 

 decidedly late. The instrument does not appear to have commenced to work till a 

 phase more closely corresponding to the maximum, than the commencement of the 

 long period waves. 



Besides the phases included in the table, there seems to be another, corresponding 

 to the increased disturbance at 17 b 54'" and 54 ra 30 s at Ischia, and at 17 h 55'5 m at 

 Potsdam. 



With these exceptions the times of commencement or of sudden increase of the 

 disturbance exhibit a very close concordance, the most serious divergence being the 

 time of commencement on the N. S. pendulum at Ischia. As this instrument 

 showed tremors continuously from 17 h 36 m 58 s , and the time given is that of a feeble 

 augmentation, it may Avell be somewhat in error owing to the difficulty of determining 



