Page:Great Neapolitan Earthquake of 1857.djvu/276

226 the toe of the sea wall, but then stood about one palm, or 10.38 inches English, below it at $$b$$. I examined into this on my return northwards, but the account of my observations will be best given here. On the 27th of February, 1858, at the lowest point of low water, of the afternoon tide at Amalfi, I found the sea-level to be 11 inches below the top of the cap sill or longitudinal timber, over the tops of the piling at the toe of the wharf wall, (which has a hollow parabolic curved sectional contour); that is to say, about half an inch below the haft-tide level $$b$$, according to Palmieri. Some loose volcanic sand, was heaped up at the foot of the wall above the permanent gravel of the beach beneath. Within a few hundred yards, I was able to find a sheltered nook between some rocks, where I noted the usual rise of tide, by the weed marks, to be 17 to 18 inches, and that high spring tides rose occasionally about 4 inches more.

I recurred to this spot at high water of the same tide, and although having to use a lanthorn, and a little wind having sprung up, I was yet able to ascertain a rise of tide of 16 inches. Returning to the quay wall, I found the water there, too agitated for direct observation; but referred to my adjacent tide gauge, the quiescent level of high water would then have been, 5 inches above the top of the cap sill, or at $$d$$, and with an 18 inch tide, 7 inches above same; or at high springs, about 11 inches above same. So that, the haft-tide level is still in reality, just about the level of the top of the cap sill at $$a$$, as fixed by Signor Palmieri before the earthquake, and no change of level of the land has taken place at this point of the coast. His erroneous conclusion, must have arisen, I presume, from his