down. The top of the same deposit (a freshwater limestone) was
perfectly even and flat, bespeaking an ancient water level. It is
suggested by Mr. Babbage that this freshwater lake may have been caused
by the fall of ashes which choked up the channel previously
communicating with the sea, so that the hot spring threw down calcareous
matter in the atrium, without any marine intermixture. To the freshwater
limestone succeeded another irregular mass of volcanic ashes and rubbish
(_f f_, fig. 90), some of it perhaps washed in by the waves of the sea
during a storm, its surface rising to ten or eleven feet above the
pavement. And thus we arrive at the period of greatest depression
expressed in the accompanying diagram, when the lower half of the
pillars were enveloped in the deposits above enumerated, and the
uppermost twenty feet were exposed in the atmosphere, the remaining or
middle portion, about nine feet long, being for years immersed in salt
water and drilled by perforating bivalves. After this period other
strata, consisting of showers of volcanic ashes and materials washed in
during storms, covered up the pillars to the height in some places of
thirty-five feet above the pavement. The exact time when these
enveloping masses were heaped up, and how much of them were formed
during submergence, and how much after the re-elevation of the temple,
cannot be made out with certainty.

The period of deep submergence was certainly antecedent to the close of
the fifteenth century. Professor James Forbes[721] has reminded us of a
passage in an old Italian writer Loffredo, who says that in 1530, or
fifty years before he wrote, which was in 1580, the sea washed the base
of the hills which rise from the flat land called La Starza, as
represented in fig. 90, so that, to quote his words, "a person might
then have fished from the site of those ruins which are now called the
stadium" (A, fig. 90).

But we know from other evidence that the upward movement had begun
before 1530, for the Canonico Andrea di Jorio cites two authentic
documents in illustration of this point. The first, dated Oct. 1503, is
a deed written in Italian, by which Ferdinand and Isabella grant to the
University of Puzzuoli a portion of land, "where the sea is drying up"
(che va seccando el mare); the second, a document in Latin, dated May
23, 1511, or nearly eight years after, by which Ferdinand grants to the
city a certain territory around Puzzuoli, where the grou