CHAPTER XXXIV.
SIGNOR D'ERRICO'S DOCUMENT—CALCULATION OF THE MOMENT OF SHOCK AT HIS STATION.
Signor D'Errico, was not at Potenza on the night of the earthquake, but at a country-house a considerable distance to the east of it, and from him I received a written statement of his observations, which are of much interest, more especially as respects time. I subjoin a translation of his communication (with the exception of some speculations as to the cause of earthquakes) which he obligingly wrote out for me, while I was occupied elsewhere in the city, and handed to me before my departure.
Translation.
"I, Guiseppe D'Errico, architect, do truly certify, the following narrative of facts to have been observed by me, during the terrible earthquake that occurred in this province of Basilicata, on the night of the 16th December, 1857:—
"On that night, I was a visitor at a large country-house, known to the surrounding inhabitants as 'Il Casone'—the Big house—and had made all my preparations with instruments, &c., for commencing early the next morning, a survey and geometrical plan, of the place and its environs. The
