Page:Great Neapolitan Earthquake of 1857 Vol 2.djvu/161

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110
THE SYNDICO'S WATCH—WAVE AMPLITUDE.

the moment of the great pulse, of the first shock, and he saw the watch run forward upon the nail, from the face of the wall, nearly as far as the latter would permit, namely until the ring should come in contact with the head of the nail. At the same time, the watch oscillated, in a plane parallel with the face of the wall (east and west) from 30° to 40% i.e., or half these at each side the vertical. The moment it got stopped by the head of the nail, the watch began to gyrate, i.e., to oscillate as a conical pendulum. The Syndico, a gentleman of shrewd observation and with all that clearness of mind that characterizes the people of Southern Italy, repeated the movements for me with the watch, by hand. We obtain from his observation a very tolerable estimate of the horizontal amplitude of the wave at Barielle, which was obviously about 1·25 inch, or 1·30 inch, in a north and south direction, and a little less in the direction of east and west, or about 1·76 inch in the path of normal vibration.

He noted the time of the first shock by this watch, which, in Frankish time, was 10h 8m, Barielle time. The watch was adjusted by sunset, but he could not guarantee that it was right within a minute or two. In Naples time it is as follows:—

h. m. s.
Watch noted at Barielle 10 8 0
Naples, west of Barielle, in time 0 5 45
Time of the shock, Naples mean time 10 2 15

The clear impression of the Syndico, and of two or three of the inhabitants then present with us, is, that the direction of the shock was from the S.W., and from a point rather