Page:Physical Geography of the Sea and its Meteorology.djvu/433

Rh latitudes, the variable character of all the currents of the sea—now fast, now slow (§ 401), now running this way, then that—all of which may be taken as so many signs of the tremendous throes which occur in the bosom of the ocean. Sometimes the sea recedes from the shore, as if to gather strength for a great rush against its barriers, as it did when it fled back to join with the earthquake and overwhelm Callao in 1746, and again Lisbon nine years afterward.

the rate, I should judge, of twenty-five miles an hour—it assumed the appearance of an alabaster wall, or, rather, of a cataract four or five miles across, and about thirty feet high, moving bodily onward. Soon it reached the advanced guard of the immense assemblage of vessels awaiting its approach. Knowing that the bore of the Hooghly, which scarcely deserves mention in connection with the one before me, invariably overturned boats which were not skilfully managed, I could not but feel apprehensive for the lives of the floating multitude. As the foaming wall of water dashed impetuously onward, they were silenced, all being intensely occupied in keeping their prows towards the wave which threatened to submerge everything afloat; but they all vaulted as it were to the summit with perfect safety. The spectacle was of great interest when the eagre had passed about one half way among the craft. On one side they were quietly reposing on the surface of the unruffled stream, while those on the nether portion were pitching and heaving in tumultuous confusion on the flood; others were scaling with the agility of salmon the formidable cascade. This grand and exciting scene was but of a moment's duration; it passed up the river in an instant, but from this point with gradually diminishing force, size, and velocity, until it ceased to be perceptible, which Chinese accounts represent to be eighty miles distant from the city. From ebb to flood tide the change was almost instantaneous; a slight flood continued after the passage of the wave, but it soon began to ebb. Having lost my memoranda, I am obliged to write from recollection. My impression is that the fall was about twenty feet; the Chinese say that the rise and fall is sometimes forty feet at Hang-chow, The maximum rise and fall at spring-tides is probably at the mouth of the river, or upper part of the bay, where the eagre is hardly discoverable. In the Bay of Fundy, where the tides rush in with amazing velocity, there is at one place a rise of seventy feet; but there the magnificent phenomenon in question does not appear to be known at all. It is not, therefore, where tides attain their greatest rapidity, or maximum rise and fall, that this wave is met with, but where a river and its estuary both present a peculiar configuration.

"Dryden's definition of an eagre, appended in a note to the verse above quoted from the Threnodia Atigustalis, is, 'a tide swelling above another tide,' which he says he had himself observed in the Eiver Trent. Such, according to Chinese oral accounts, is the character of the Tsien-Tang tides—a wave of considerable height rushes suddenly in from the bay, which is soon followed by one much larger. Other accounts represent three successive waves riding in; hence the name of the temple mentioned, that of the Three Waves. Both here and on the Hooghly I observed but one wave; my attention, however, was not