Periods when the Temple of Serapis sank and rose.-The next subject of inquiry is the era when these remarkable changes took place in the Bay of Baiæ. It appears that in the Atrium of the Temple of Serapis, inscriptions were found in which Septimius Severus and Marcus Aurelius record their labours in adorning it with precious marbles.* We may, therefore, conclude, that it existed at least down to the third century of our era in its original position; and it may have been built at the close of the second century. On the other hand, we have evidence that the marine deposit forming the flat land, called La Starza, was still covered by the sea in the year 1530, or just eight years anterior to the tremendous explosion of Monte Nuovo. Mr. Forbes has lately pointed out the distinct testimony of an old Italian writer, Loffredo, in confirmation of this important point.t Writing in 1580, Loffredo declares that, fifty years previously, the sea washed the base of the hills which rise from the flat land before alluded to; and at that time he expressly tells us, that a person might have fished from the site of those ruins which are now called the Stadium. (See Fig. 55, p. 426.) Hence it follows, that the subsidence of the ground happened at some period between the third century, when the temple was still standing, and the beginning of the sixteenth century, when its site was still submerged. Now, in this interval the only two events which are recorded in the imperfect annals of the dark ages are, the eruption of the Solfatara in 1198, and an earthquake in 1488, by which Puzzuoli was ruined. It is at least highly probable, that earthquakes, which preceded the eruption of the Solfatara, which is very near the temple (See Fig. 55, p. 426), caused a subsidence, and the pumice and other matters ejected from that volcano might have fallen in heavy showers into the sea, and would thus immediately have covered up the lower part of the columns, and preserved them from the action of the sea and from lithodomous perforations. The waves might afterwards have thrown down many pillars, and formed strata of broken fragments of buildings, intermixed with volcanic ejections, and thus have caused those strata, containing works of art and shells, which extend for several miles along the coast. Mr. Babbage, after carefully examining several incrustations of carbonate of lime, such as the waters of the hot spring might have deposited, adhering to the walls and columns of the temple at different heights, as also the distinct marks of ancient lines of water level, visible below the zone of lithophagous perforations, has come to the conclusion, and, I think, proved, that the subsidence of the building was not sudden, or at one period only, but gradual, and by successive movements.‡ As to the re-elevation of the depressed tract, that may also have occur * Brieslak, Voy. dans la Campanie, tom. ii. p. 167. * Ed. Journ. of Science, new series, No. II. p. 281. t Proceedings of Geol. Soc., No. 36. March 1834. VOL. I.-3 E red at different periods, since earthquakes are not unfrequent in this country. 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 ground is dried up from the sea (desiccatum).* It is perfectly evident, however, from Loffredo's statement, that the principal elevation of the low tract called La Starza took place after the year 1530, and some time before the year 1580; and from this alone we might have suspected that the change happened in the year 1538, when Monte Nuovo was formed. But, fortunately, we are not left in the slightest doubt that such was the date of this remarkable event. Sir William Hamilton has given us two original letters describing the eruption of 1538, the first of which, by Falconi, dated 1538, contains the following passages.t "It is now two years since there have been frequent earthquakes at Fuzzuoli, Naples, and the neighbouring parts. On the day and in the night before the eruption (of Monte Nuovo), above twenty shocks, great and small, were felt. The eruption began on the 29th of September, 1538. It was on a Sunday, about one o'clock in the night, when flames of fire were seen between the hot baths and Tripergola. In a short time the fire increased to such a degree, that it burst open the earth in this place, and threw up so great a quantity of ashes and pumice stones, mixed with water, as covered the whole country. The next morning (after the formation of Monte Nuovo) the poor inhabitants of Puzzuoli quitted their habitations in terror, covered with the muddy and black shower which continued the whole day in that country-flying from death, but with death painted in their countenances. Some with their children in their arms, some with sacks full of their goods; others leading an ass, loaded with their frightened family, towards Naples ; others carrying quantities of birds of various sorts, that had fallen dead at the beginning of the eruption; others, again, with fish which they had found, and which were to be met with in plenty on the shore, the sea having left them dry for a considerable time. I accompanied Signor Moramaldo to behold the wonderful effects of the eruption. The sea had retired on the side of Baiæ, abandoning a considerable tract, and the shore appeared almost entirely dry, from the quantity of ashes and broken pumice stones thrown up by the eruption. I saw two springs in the newly discovered ruins: one before the house that was the queen's, of hot and salt water," &c. So far Falconi; the other account is by Pietro Giacomo di Toledo, Sul Tempio di Serap. chap. viii. + Campi Phlegræi, p. 70. which begins thus:-"It is now two years since this province of Campagna has been afflicted with earthquakes, the country about Puzzuoli much more so than any other parts: but the 27th and 28th of the month of September last, the earthquakes did not cease day or night in the town of Puzzuoli: that plain which lies between Lake Avernus, the Monte Barbaro, and the sea, was raised a little, and many cracks were made in it, from some of which issued water; at the same time the sea immediately adjoining the plain dried up about two hundred paces, so that the fish were left on the sand a prey to the inhabitants of Puzzuoli. At last, on the 29th of the same month, about two o'clock in the night, the earth opened," &c. Now, both these accounts, written immediately after the birth of Monte Nuovo, agree in expressly stating that the sea retired, and one mentions that its bottom was upraised. To this elevation we have already seen that Hooke, writing at the close of the seventeenth century, alludes as to a well-known fact. The preposterous theories, therefore, that have been advanced in order to dispense with the elevation of the land, in the face of all this historical and physical evidence, are not entitled to a serious refutation. Encroachments of the sea in the Bay of Baix.-The flat land, when first upraised, must have been more extensive than now, for the sea encroaches somewhat rapidly, both to the north and south-east of Puzzuoli. The coast has, of late years, given way more than a foot in a twelvemonth; and I was assured, by fishermen in the bay, that it has lost ground near Puzzuoli, to the extent of thirty feet, within their memory. It is, probably, this gradual encroachment, which has led many authors to imagine that the level of the sea is slowly rising in the Bay of Baiæ; an opinion by no means warranted by such circumstances. In the course of time, the whole of the low land will, perhaps, be carried away, unless some earthquake shall remodify the surface of the country, before the waves reach the ancient coast-line; but the removal of this narrow tract will by no means restore the country to its former state, for the old tufaceous hills, and the interstratified current of trachytic lava which has flowed from the Solfatara, must have participated in the movement of 1538; and these will remain upraised, even though the sea may regain its ancient limits. In 1828, excavations were made below the marble pavement of the Temple of Serapis, and another costly pavement of mosaic was found, at the depth of five feet or more below the other. The existence of these two pavements, at different levels, seems clearly to imply some subsidence previously to all the changes already alluded to, which had rendered it necessary to construct a new floor at a higher level. But to these and other circumstances bearing on the history of the Temple antecedently to * Ante, p. 46. the revolutions already explained, I shall not refer at present, trusting that future investigations will set them in a clearer light. Permanence of the ocean's level.-In concluding this subject, I may observe, that the interminable controversies to which the phenomena of the Bay of Baiæ gave rise, have sprung from an extreme reluctance to admit that the land, rather than the sea, is subject alternately to rise and fall. Had it been assumed that the level of the ocean was invariable, on the ground that no fluctuations have as yet been clearly established, and that, on the other hand, the continents are inconstant in their level, as has been demonstrated by the most unequivocal proofs again and again, from the time of Strabo to our own times, the appearances of the Temple at Puzzuoli could never have been regarded as enigmatical. Even if contemporary accounts had not distinctly attested the upraising of the coast, this explanation should have been proposed in the first instance as the most natural, instead of being now adopted unwillingly when all others have failed. To the strong prejudices still existing in regard to the mobility of the land, we may attribute the rarity of such discoveries as have been recently brought to light in the Bay of Baie and the Bay of Conception. A false theory, it is well known, may render us blind to facts which are opposed to our prepossessions, or may conceal from us their true import when we behold them. But it is time that the geologist should, in some degree, overcome those first and natural impressions which induced the poets of old to select the rock as the emblem of firmness-the sea as the image of inconstancy. Our modern poet, in a more philosophical spirit, saw in the sea "The image of Eternity," and has finely contrasted the fleeting existence of the successive empires which have flourished and fallen on the borders of the ocean with its own unchanged stability. Their decay Has dried up realms to deserts :—not so thou, CHILDE HAROLD, Canto iv. CHAPTER XVII. ELEVATION AND SUBSIDENCE OF LAND WITHOUT EARTHQUAKES. Changes in the relative level of land and sea in regions not volcanic-Opinion of Celsius that the waters of the Baltic Sea and Northern Ocean were sinking-Objections raised to his opinion-Proofs of the stability of the sea-level in the Baltic -Playfair's hypothesis that the land was rising in Sweden-Opinion of Von Buch (p. 441.)-Marks cut on the rocks-Survey of these in 1820-Facility of detecting slight alterations in level of sea on coast of Sweden-Shores of the ocean also rising—Area upheaved (p. 444.)-Shelly deposits of Uddevalla-Of Stockholm, containing fossil shells characteristic of the Baltic-Whether subsidence in Sweden-Fishing-hut buried under marine strata (p. 447.)—Sinking of land in Greenland-Bearing of these facts on geological phenomena. We have now considered the phenomena of volcanos and earthquakes according to the division of the subject before proposed (p. 291), and have next to turn our attention to those slow and insensible changes in the relative level of land and sea which take place in countries remote from volcanos, and where no violent earthquakes have occurred within the period of human observation. Early in the last century the Swedish naturalist, Celsius, expressed his opinion that the waters, both of the Baltic and Northern Ocean, were gradually subsiding. From numerous observations he inferred, that the rate of depression was about forty Swedish inches in a century. In support of this position, he alleged that there were many rocks both on the shores of the Baltic and the ocean known to have been once sunken reefs, and dangerous to navigators, but which were in his time above water-that the waters of the Gulf of Bothnia had been gradually converted into land, several ancient ports having been changed into inland cities, small islands joined to the continent, and old fishing-grounds deserted as being too shallow, or entirely dried up. Celsius also maintained, that the evidence of the change rested not only on modern observations, but on the authority of ancient geographers, who had stated that Scandinavia was formerly an island. This island, he argued, must, in the course of centuries, by the gradual retreat of the sea, have become connected with the continent; an event which he supposed to have happened after the time of Pliny, and before the ninth century of our era. To this argument it was objected that the ancients were so ignorant of the geography of most northern parts of Europe, that their authority was entitled to no weight; and that their representation of Scandinavia as an * The Swedish measure scarcely differs from ours; the foot being divided into twelve inches, and being less than ours by three-eighths of an inch only. |