genetic connection between fringing or shore-reefs, island-encircling
reefs, and lagoon-islands, _i. e._, narrow ring-shaped reefs enclosing
interior lagoons. According to his views these three varieties of
form are dependent on the oscillating condition of the bottom of the
sea, or on periodic elevations and subsidences. The hypothesis which
has been several times put forward, according to which the closed
ring or annular form of the coral-reefs in Atolls or Lagoon Islands
marks the configuration of a submarine volcano, the structure having
been raised on the margin of the crater, is opposed by their great
dimensions, the diameters of many of them being 30, 40, and sometimes
even 60 geographical miles. Our fire-emitting mountains have no such
craters; and if we would compare the lagoon, with its submerged
interior and narrow enclosing reef, to one of the annular mountains
of the moon, we must not forget that those lunar mountains are not
volcanoes, but wall-surrounded districts. According to Darwin, the
process of formation is the following:--He supposes a mountainous
island surrounded by a coral-reef, (a “fringing reef” attached to the
shore), to undergo subsidence: the “fringing reef” which subsides with
the island is continually restored to its level by the tendency of the
coral-animals to regain the surface of the sea, and becomes thus, as
the island gradually sinks and is reduced in size, first an “encircling
reef” at some distance from the included islet, and subsequently, when
the latter has entirely disappeared, an atoll. According to this view,
in which islands are regarded as the culminating points of a submerged
land, the relative positions of the different coral islands would
disclose to us that which we could hardly learn by the sounding line,
concerning the configuration of the land which was above the surface of
the sea at an earlier epoch. The entire elucidation of this attractive
subject, (to the connection of which with the migrations of plants and
the diffusion of races of men attention was called at the commencement
of the present note), can only be hoped for when inquirers shall have
succeeded in obtaining greater knowledge than is now possessed of the
depth and the nature of the rocks on which the lowest strata of the
dead corals rest.
[8] p. 11.--“_Traditions of Samothrace._”
Diodorus has preserved to us this remarkable tradition, the probability
of which renders it in the eyes of the geologist almost equivalent to
a historical certainty. The Island of Samothrace, formerly called also
Æthiopea, Dardania, Leucania or Leucosia in the Scholiast to Apollonius
Rhodius, and which was a seat of the ancient mysteries of the Cabiri,
was inhabited by the remains of an ancient nation, several words of
whose language were preserved to a later period in the ceremonies
accompanying sacrifices. The situation of this island, opposite to the
Thracian Hebrus and near the Dardanelles, renders it not surprising
that a more detailed tradition of the catastrophe of the breaking forth
of the waters of the Euxine should have been preserved there. Rites
were performed at altars supposed to mark the limits of the irruption
of the waves; and in Samothrace as well as in Bœotia, a belief in the
periodically recurring destruction of mankind, (a belief which was also
found among the Mexicans in the form of a myth of four destructions of
the world), was connected with historical recollections of particular
inundations. (Otfr. Müller Geschichten Hellenischer Stämme und Städte,
Bd. i. S. 65 and 119.) According to Diodorus, the Samothracians related
that the Black Sea had once been an inland lake, but that, being
swollen by the rivers which flow into it, it had broken through, first
the strait of the Bosphorus, and afterwards that of the Hellespont; and
this long before the inundations spoken of by other nations. (Diod.
Sicul. lib. v. cap. 47, p. 369, Wesseling.) These ancient revolutions
of nature have been treated of in a special work by Dureau de la Malle,
and all the information possessed on the subject has been collected in
Carl von Hoff’s important work, entitled Geschichte der natürlichen
Veränderungen der Erdoberfläche, Th. i. 1822, S. 105-162; and in
Creuzer’s Symbolik, 2te Aufl. Th. ii. S. 285, 318, and 361. A reflex,
as it were, of the traditions of Samothrace appears in the “Sluice
theory” of Strato of Lampsacus, according to which the swelling of the
waters of the Euxine first opened the passage of the Dardanelles, and
afterwards caused the outlet through the pillars of Hercules. Strabo
has preserved to us in the first book of his Geography, among critical
extracts from the works of Eratosthenes, a remarkable fragment of the
lost writings of Strato, presenting views which extend to almost the
entire circumference of the Mediterranean.
“Strato of Lampsacus,” says Strabo (Lib. i. p. 49 and 50, Casaub.),
“is even more disposed than the Lydian Xanthus,” (who had described
impressions of shells at a distance from the sea) “to expound the
causes of the things which we see. He asserts that the Euxine had
formerly no outlet at Byzantium, but the sea becoming swollen by the
rivers which ran into it, had by its pressure opened the passage
through which the waters flow into the Propontis and the Hellespont.
He also says that the same thing has happened to our Sea (the
Mediterranean);” “for here, too, when the sea had become swollen by the
rivers, (which in flowing into it had left dry their marshy banks), it
forced for itself a passage through the isthmus of land connecting the
Pillars. The proofs which Strato gives of this are, first that there is
still a bank under water running from Europe to Libya, shewing that the
outer and inner seas were formerly divided; and next that the Euxine
is the shallowest, the Cretan, Sicilian, and Sardoic Seas being on the
contrary very deep; the reason being that the Euxine has been filled
with mud by the many and large rivers flowing into it from the North,
while the other seas continued deep. The Euxine is also the freshest,
and the waters flow towards the parts where the bottom of the sea is
lowest. Hence he inferred that the whole of the Euxine would finally
be choked with mud if the rivers were to continue to flow into it: and
this is already in some degree the case on the west side of the Euxine
towards Salmydessus (the Thracian Apollonia), and at what are called
by mariners the “Breasts” off the mouth of the Ister and along the
shore of the Scythian Desert. Perhaps the Temple of Ammon (in Lybia)
may once have stood on the sea-shore, and causes such as these may
explain why it is now far inland. This Strato thought might account
for the celebrity of the Oracle, which would be less surprising if it
had been on the sea-shore; whereas its great distance from the coast
made its present renown inexplicable. Egypt, too, had been formerly
overflowed by the sea as far as the marshes of Pelusium, Mount Casius,
and Lake Serbonis; for, on digging beneath the surface, beds of
sea-sand and shells are found; shewing that the country was formerly
overflowed, and the whole district round Mount Casius and Gerrha was
a marshy sea which joined the gulf of the Red Sea. When our Sea (the
Mediterranean) retreated, the land was uncovered; still, however,
leaving the Lake of Serbonis: subsequently this lake also broke through
its bounds and the water flowed off, so that the lake became a swamp.
The banks of Lake Mœris are also more like sea than river banks.” An
erroneously corrected reading introduced by Grosskurd on account of
a passage in Strabo, Lib. xvii. p. 809, Cas., gives instead of Mœris
“the Lake Halmyris:” but this latter lake was situated not far from the
mouth of the Danube.
The sluice-theory of Strato led Eratosthenes of Cyrene (the most
celebrated of the series of librarians of Alexandria, but less
happy than Archimedes in writing on floating bodies), to examine
the problem of the equality of level of all external seas, _i. e._,
seas surrounding the Continents. (Strabo, Lib. i. p. 51-56; Lib. ii.
p. 104, Casaub). The varied outlines of the northern shores of the
Mediterranean, and the articulated form of the peninsulas and islands,
had given occasion to the geognostical myth of the ancient land of
Lyctonia. The supposed mode of origin of the smaller Syrtis and of the
Triton Lake (Diod. iii. 53-55) as well as that of the whole Western
Atlas (Maximus Tyrius, viii. 7) were drawn in to form part of an
imaginary scheme of igneous eruptions and earthquakes. (See my Examen
crit. de l’hist. de la Géographie, Vol. i. p. 179; T. iii. p. 136.) I
have recently touched more in detail on this subject (Kosmos, Bd. ii.
S. 153; Engl. ed. p. 118-119) in a passage which I permit myself to
subjoin:--
A more richly varied and broken outline gives to the northern shore
of the Mediterranean an advantage over the southern or Lybian shore,
which according to Strabo was remarked by Eratosthenes. The three great
peninsulas, the Iberian, the Italian, and the Hellenic, with their
sinuous and deeply indented shores, form, in combination with the
neighbouring islands and opposite coasts, many straits and isthmuses.
The configuration of the continent and the islands, the latter either
severed from the main or volcanically elevated in lines, as if over
long fissures, early led to geognostical views respecting eruptions,
terrestrial revolutions, and overpourings of the swollen higher seas
into those which were lower. The Euxine, the Dardanelles, the Straits
of Gades, and the Mediterranean with its many islands, were well fitted
to give rise to the view of such a system of sluices. The Orphic
Argonaut, who probably wrote in Christian times, wove antique legends
into his song; he describes the breaking up of the ancient Lyktonia
into several islands, when ‘the dark-haired Poseidon, being wroth
with Father Kronion, smote Lyktonia with the golden trident.’ Similar
phantasies, which indeed may often have arisen from imperfect knowledge
of geographical circumstances, proceeded from the Alexandrian school,
where erudition abounded, and a strong predilection was felt for
antique legends. It is not necessary to determine here whether the myth
of the Atlantis broken into fragments should be regarded as a distant
and western reflex of that of Lyktonia (as I think I have elsewhere
shewn to be probable), or whether, as Otfried Müller considers,
“the destruction of Lyktonia (Leuconia) refers to the Samothracian
tradition of a great flood which had changed the form of that district.”
[9] p. 12.--“_Prevents precipitation taking place from clouds._”
The vertically-ascending current of the atmosphere is a principal
cause of many most important meteorological phenomena. When a desert
or a sandy plain partly or entirely destitute of plants is bounded
by a chain of high mountains, we see the sea breeze drive the dense
clouds over the desert without any precipitation taking place before
they have reached the mountain-ridge. This phenomenon was formerly
explained in a very inappropriate manner by a supposed superior
attraction exercised by the mountains on the clouds. The true reason
of the phenomenon appears to consist in the ascending column of warm
air which rises from the sandy plain, and prevents the vesicles
of vapour from being dissolved. The more complete the absence of
vegetation, and the more the sand is heated, the greater is the height
of the clouds, and the less can any fall of rain take place. When the
clouds reach the mountains these causes cease to operate; the play of
the vertically-ascending atmospheric current is feebler, the clouds
sink lower, and dissolve in rain in a cooler stratum of air. Thus,
in deserts, the _want of rain_, and the _absence of vegetation_, act
and react upon each other. It does not rain, because the naked sandy
surface having no vegetable covering, becomes more powerfully heated by
the solar rays, and thus radiates more heat; and the absence of rain
forbids the desert being converted into a steppe or grassy plain,
because without water no organic development is possible.
[10] p. 14.--“_The mass of the earth in solidifying and parting with
its heat._”
If, according to the hypothesis of the Neptunists, now long since
obsolete, the so-called primitive rocks were precipitated from a fluid,
the transition of the crust of the earth from a fluid to a solid state
must have been accompanied by an enormous disengagement of heat, which
would in turn have caused fresh evaporation and fresh precipitations.
The later these precipitations, the more rapid, tumultuous, and
uncrystalline they would have been. Such a sudden disengagement of heat
_might_ cause local augmentations of temperature independent of the
height of the pole or the latitude of the place, and independent of the
position of the earth’s axis; and the temperatures thus caused would
influence the distribution of plants. The same sudden disengagement of
heat might also occasion a species of porosity, of which there seem to
be indications in many enigmatical geological phenomena in sedimentary
rocks. I have developed these conjectures in detail in a small memoir
“über ursprungliche Porosität.” (See my work entitled Versuche über
die chemische Zersetzung des Luftkreises, 1799, S. 177; and Moll’s
Jahrbücher der Berg- und Hüttenkunde, 1797, S. 234.) According to the
newer views which I now entertain, the shattered and fissured earth,
with her molten interior, may long have maintained a high temperature
on her oxydised surface, independently of position in respect to the
sun and of latitude. Would not the climate of Germany be wonderfully
altered, and that perhaps for centuries, if there were opened a fissure
a thousand fathoms in depth, reaching from the shores of the Adriatic
to the Baltic? If in the present condition of our planet, the stable
equilibrium of temperature, first calculated by Fourier in his Théorie
analytique de la chaleur, has been almost completely restored by
radiation from the earth into space; and if the external atmosphere now
only communicates with the molten interior through the inconsiderable
openings of a few volcanoes,--in the earlier state of things numerous
clefts and fissures, produced by the frequently recurring corrugations
of the rocky strata of the globe, emitted streams of heated air which
mingled with the atmosphere and were entirely independent of latitude.
Every planet must thus in its earliest condition have for a time
determined its own temperature, which afterwards becomes dependent on
the position relatively to the central body, the Sun. The surface of
the Moon also shows traces of this reaction of the interior upon the
crust.
[11] p. 14.--“_The mountain declivities of the southern part of
Mexico._”
The greenstone in globular concretions of the mountain district of
Guanaxuato is quite similar to that of the Franconian Fichtel-Gebirge.
Both form grotesquely shaped summits, which pierce through and cover
the transition argillaceous schists. In the same manner, pearl stone,
porphyritic schists, trachyte, and pitch-stone porphyry, constitute
rocks similar in form in the Mexican mountains near Cinapecuaro and
Moran, in Hungary, in Bohemia, and in Northern Asia.
[12] p. 16.--“_The dragon-tree of Orotava._”
This colossal dragon-tree, Dracæna draco, stands in the garden of Dr.
Franqui in the small town of Oratava, the ancient Taoro, one of the
most delightful spots in the world. In June 1799, when we ascended the
Peak of Teneriffe, we measured the circumference of the tree, and found
it nearly 48 English feet. Our measurement was taken several feet above
the root. Lower down, and nearer to the ground, Le Dru made it nearly
79 English feet. Sir George Staunton found the diameter still as much
as 12 feet at the height of 10 feet above the ground. The height of
the tree is not much above 69 English feet. According to tradition,
this tree was venerated by the Guanches (as was the ash-tree of Ephesus
by the Greeks, or as the Lydian plane-tree which Xerxes decked with
ornaments, and the sacred Banyan-tree of Ceylon), and at the time of
the first expedition of the Béthencourts in 1402, it was already as
thick and as hollow as it now is. Remembering that the Dracæna grows
extremely slowly, we are led to infer the high antiquity of the tree
of Orotava. Bertholet, in his description of Teneriffe, says, “En
comparant les jeunes Dragonniers, voisins de l’arbre gigantesque, les
calculs qu’on fait sur l’age de ce dernier effraient l’imagination.”
(Nova Acta Acad. Leop. Carol. Naturæ Curiosorum, T. xiii. 1827, p.
781.) The dragon-tree has been cultivated in the Canaries, and in
Madeira and Porto Santo, from the earliest times; and an accurate
observer, Leopold von Buch, has even found it wild in Teneriffe, near
Igueste. Its original country, therefore, is not India, as had long
been believed; nor does its appearance in the Canaries contradict the
opinion of those who regard the Guanches as having been an isolated
Atlantic nation without intercourse with African or Asiatic nations.
The form of the Dracænas is repeated at the southern extremity of
Africa, in the Isle of Bourbon, and in New Zealand. In all these
distant regions species of the genus in question are found, but none
have been met with in the New Continent, where its form is replaced by
that of the Yucca. Dracæna borealis of Aiton is a true Convallaria,
and has all the “habitus” of that genus. (Humboldt, Rel. hist. T. i.
p. 118 and 639.) I have given a representation of the dragon-tree of
Orotava, taken from a drawing made by F. d’Ozonne in 1776, in the
last plate of the Picturesque Atlas of my American journey. (Vues
des Cordillères et Monumens des Peuples indigènes de l’Amérique, Pl.
lxix.) I found d’Ozonne’s drawing among the manuscripts left by the
celebrated Borda, in the still unprinted travelling journal entrusted
to me by the Dépôt de la Marine, and from which I borrowed important
astronomically-determined geographical, as well as barometric and
trigonometric notices. (Rel. hist. T. i. p. 282.) The measurement of
the dragon-tree of the Villa Franqui was made on Borda’s first voyage
with Pingré, in 1771; not in his second voyage, in 1776, with Varela.
It is affirmed that in the early times of the Norman and Spanish
Conquests, in the 15th century, Mass was said at a small altar erected
in the hollow trunk of the tree. Unfortunately the dragon-tree of
Orotava lost one side of its top in the storm of the 21st of July,
1819. There is a fine and large English copperplate engraving which
represents the present state of the tree with remarkable truth to
nature.
The monumental character of these colossal living vegetable forms,
and the kind of reverence which has been felt for them among all
nations, have occasioned in modern times the bestowal of greater
care in the numerical determination of their age and the size of
their trunks. The results of these inquiries have led the author
of the important treatise, “De la longévité des Arbres,” the elder
Decandolle, Endlicher, Unger, and other able botanists, to consider
it not improbable that the age of several individual trees which are
still alive goes back to the earliest historical periods, if not of
Egypt, at least of Greece and Italy. It is said in the Bibliothèque
Universelle de Genève, 1831, T. lxvii. p. 50:--“Plusieurs exemples
semblent confirmer l’idée qu’il existe encore sur le globe des arbres
d’une antiquité prodigieuse, et peut-être témoins de ses dernières
révolutions physiques. Lorsqu’on regarde un arbre comme un agrégat
d’autant d’individus soudés ensemble qu’il s’est développé de bourgeons
à sa surface, on ne peut pas s’étonner si, de nouveaux bourgeons
s’ajoutant sans cesse aux anciens, l’agrégat qui en résulte n’a point
de terme nécessaire à son existence.” In the same manner Agardh
says:--“If in trees there are produced in each solar year new parts,
so that the older hardened parts are replaced by new ones capable of
conducting sap, we see herein a type of growth limited only by external
causes.” He ascribes the shortness of the life of herbs, or of such
plants as are not trees, “to the preponderance of the production of
flowers and fruit over the formation of leaves.” Unfruitfulness is to
a plant a prolongation of life. Endlicher cites the example of a plant
of Medicago sativa, var. β versicolor, which, bearing no fruit, lived
eighty years. (Grundzüge der Botanik, 1843, S. 1003).
With the dragon trees, which, notwithstanding the gigantic development
of their closed vascular bundles, must by reason of their floral parts
be placed in the same natural family with asparagus and garden onions,
we must associate the Adansonia (monkey bread-tree, Baobab,) as being
certainly among the largest and oldest inhabitants of our planet. In
the very first voyages of discovery of the Catalans and Portuguese, the
navigators were accustomed to cut their names on these two species of
trees, not merely to gratify the desire of handing down their names,
but also to serve as marks or signs of possession, and of whatever
rights nations claim on the ground of being the first discoverers.
The Portuguese navigators often used as their “marco” or token of
possession the French motto of the Infant Don Henrique the Discoverer.
Manuel de Faria y Sousa says in his Asia Portuguesa (T. i. cap. 2, pp.
14 and 18):--“Era uso de los primeros Navegantes de dexar inscrito
el Motto del Infante, _talent de bien faire_, en la corteza de los
arboles.” (Compare also Barros, Asia, Dec. I. liv. ii. cap. 2, T. i. p.
148; Lisboa, 1778.)
The above-named motto cut on the bark of two trees by Portuguese
navigators in 1435, twenty-eight years therefore before the death of
the Infante, is curiously connected in the history of discoveries with
the elucidations to which the comparison of Vespucci’s fourth voyage
with that of Gonzalo Coelho, in 1503, has given rise. Vespucci relates
that Coelho’s admiral’s ship was wrecked on an island which has been
sometimes supposed to be San Fernando Noronha, sometimes the Peñedo
de San Pedro, and sometimes the problematical Island of St. Matthew.
This last-named island was discovered by Garcia Jofre de Loaysa on
the 15th of October, 1525, in 2-1/2° S. lat., in the meridian of Cape
Palmas, almost in the Gulf of Guinea. He remained there eighteen days
at anchor, found crosses, as well as orange trees which had been
planted and had become wild, and on two trunks of trees inscriptions
dating back ninety years. (Navarrete, T. v. pp. 8, 247, and 401.) I
have examined the questions presented by this account more in detail
in my inquiries into the trustworthiness of Amerigo Vespucci. (Examen
critique de l’hist. de la Geographie, T. v. pp. 129-132.)