Page:Great Neapolitan Earthquake of 1857.djvu/269

Rh water which was then standing at $$a$$ (Fig. 117), had, directly after the shock of December, fallen to $$b$$, equivalent to a rise of the temple of 7 inches, but that, since that time, the water had gradually returned to its former level, i. e. the land had sunk again.

He denied that the difference could be due to variability in the sea level. The utmost limits of disturbance by wind or tide within the sheltered valley of the ruins being, according to his stated experience, far within 7 inches.

I could not find, that any man of science in Naples, had ascertained what these limits of aqueous disturbance were, and on my return to the city (from the interior), I took the occasion of a severe gale of wind in shore—the "Garbino," from the S.W.—and at the presumed time of high water, to visit the temple again, in company with Signor Guiscardi, when I found the water rather above the level of the sill of the entrance iron gate, and fully 22 inches above the level of the 5th February, and it had been nearly 3 inches higher about two hours previously.

It is obvious, therefore, that any deduction whatsoever as to levels, whether of elevation or of depression, based upon the tidal level of the Mediterranean on this coast, cannot be depended upon, within the limits of 18 inches or 2 feet at the very least; and several of the speculations as to minute oscillations of level of the Temple of Serapis so based must henceforward be received with doubt.

Impressed with this fact, in which I found that Professor Capocci and Signor Guiscardi coincided with me, and with the extreme value to physical science, of possessing, in this instable region, some definite and unimpeachable standard of level, I addressed a formal letter, upon my return to Naples