Alexander von Humboldt.

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On his way to Madrid, be deti rmined the geographical
position of several important parts, and ascertained the
height of the central plain of Ciistile. In March 1799



ith liii
olaiis.



V'iidl to
Maurid.



OBTAINS LEAVE TO VISIT SPANISH COLOMKS. 21

he was presented at the court of Aranjucz, and gra- chai>. u
ciously received by the king, to Avhom he explained pian~of~
the motives which induced him to undertake a voyage ^''^'t ^"
to the New Continent. Being seconded in his applica-
tion by the representations of an enlightened minister,
Don Mariano Luis de Urquijo, he to his great joy ob-
tained leave to visit and explore, without impediment
or restriction, all the Spanish territories in America.
The impatience of the travellers to take advantage of
the permission thus granted did not allow them to
bestow much time upon preparations ; and about the
middle of May they left Madrid, crossed part of Old
Castile, Leon, and Galicia, and betook themselves to
Corunna, whence they were to sail for the island of
Cuba.

According to the observations made by our travellers. Observations
the interior of Spain consists of an elevated table-land, "* ^'^"''
formed of secondary deposites, — sandstone, gypsum,
rock-salt, and Jura limestone. The climate of the
Castiles is much colder tlian that of Toulon and Genoa,
its mean temperature scarcely rising to 59° of Fahren-
heit's thermometer. The central plain is surrounded
by a low and narrow belt, in several parts of which the
fan-palm, the date, the sugar-cane, the banana, and
many plants common to Spain and the north of Africa,
vegetate, without suffering from tlie severity of the
winter. In the space included between the parallels
of thirty-six and forty degrees of nortli latitude the
mean temperature ranges from 62° to G8° Fahrenheit,
and by a concurrence of favourable circumstances this
section has become tlie jjrincipal scat of industry and
intellectual cultivation.

Ascending from the shores of the Mediterranean, to- '''ain of La
wards the elevated plains of La Mancha and the Castiles,
one imagines that he sees far inland, in the extended
precipices, the ancient coast of the Peninsula, — a cir-
cumstance which brings to mind the traditions of the
Samothracians and certain historical testimonies, accord-
ing to which the bursting: of the waters through the



oo



AHKIVAI, AT COKUNNA.



DardanclK-s, while it enlarged the basin of the Mediter-
ranean, overwhelmed the southern part of Europe.
The high central plain just descrihcd would, it may be
presumed, resist tlie effects of the inundation until the
escape of the waters by the strait formed l)etween the
Pillars of lli'rcules had gradually lowered the level of
the Mediterianean, and thereby once more laid bare
Upper Egypt on the one hand, and on the other the
fertile valleys of Tarragon, Valentia, and Mureia.

From Astoi-ga to Corunna the mountains gradually
rise, the secondary strata disappear l)y degrees, and the
transition- rocks which succeed announce tiie proximity
of primitive formations. Large mountains of gray wacke
and gray wacke-slate present themselves. In the vici-
nity of the latter town are granitic summits which
extend to Cape Ortegal, and which might seem, with
those of Brittany and Cornwall, to have once formed a
chain of mountains that has l)een broken up and sub-
mersed. This rock is characterized by large and
beautiful crystals of felspar, and contains tin-ore, which
is worked with much labour and little profit by the
Galicians.

On arriving at Corunna, they found the port block-
aded by the English, for the purpose of interrupting
the communication between the mother-country and
the American colonies. The principal secretary of state
had recommended them to Don Raliiel Clavigo, recentl}'
appointed director-general of the maritime posts, who
neglected nothing that could render their residence
agreeable, and advised them to enibark on board the
corvette Pizarro bound for Ilavannah and Mexico.
Instructions were given for the safe disposal of the
iiistrunu-nts, and the captain was ordered to stop at
TcncriHc so loni; as should be found necessary to en-
able the travellers to visit the port of Orotava and
n-scend the IVak.

During the few days of their detention, they occupied
thcnisclvcs in j)r(i)aring the i)lants which they had
collected, and in makiim sundry obsur\\».tioijs. Crossing



TEMPERATLRE OP THE SEA 23

to FciTol they made some interesting- experiments on CUAP. I.
the temperature of the sea and the decrease of heat in KxperimentB
the successive strata of the water. The thermometer '-^^ i'enol
on the bank and near it was from 5-i'5^ to 55-9°, while
in deep water it stood at 59° or 59-5°, the air being 55°.
The fact that the proximity of a sand-bank is indicated
by a rapid descent of the temperature of the sea at its
surface, is of great importance for the safety of navi-
gators ; for, although the use of the thermometer ought
not to supersede that of the lead, variations of tempera-
ture indicative of danger may be perceived by it long
before the vessel reaches the shoal. A heavy swell
from the north-west rendered it impossible to continue
their experiments. It was produced by a storm at sea,
and obliged the English vessels to retire from the coast,
— a circumstance which induced our travellers speedily
to embark their instruments and baggage, although they
were prevented from sailing by a high westerly wind
that continued for several days.



24



DEPAUTUUE FROM CORUNAA.



CHAPTER II.

Voyage from Corunna to Teneriffe.

Departure from Corunna — Currents of the Atlantic Ocean — Ma-
rine Animals — Falling Stars — Swallows — Canary Islands— Lan-
cerota — Fucus vitifolius — Causes of the Green Colour of Plants
— La Graciosa— Stratified Basalt alternating^ with Marl — Hj-a-
lite — ^Quartz Sand — Remarks on the Distance at which Mountains
are visible at Sea, and the Causes by which it is modified — Land-
iuir at Teneriffe.



lu^piirture
from Co-
runna.



tvcninc

lioriiuu ul
•cu.



The wind having come round to the north-east, the
Pizarro set sail on the afternoon of the 5th of June
1799, and after working out of the narrow passage
passed the Tower of Hercules, or lighthouse of Corunna,
at half-past six. Towards evening the wind increased,
and the sea ran high. They directed their couree to the
north-west, for the purpose of avoiding the English
frigates which wore cruising off the coast, and about
nine spied the fire of a fishing-liut at Si.'iitrga, which
was tlie last oliject they bclield in the west of Europe.
As tliey advanced, the light mingled itself witli the
stars which rose on tlie horizon. " Our eyes," says
Huinl)oldt, " remained involuntarily fixed upon it.
Such impressions do not fode from tlie memory of tiiose
wlio have undertaken long voyages at an age when the
emotions of tlie heart are in full force. How many
recollections are awakened in tite imagination by a
luminous jjoint, wliit-li in the middle of a dark night,
appearing at intervals above the agitated waves, marks
tliu shore of one's native land !"



EQUINOCTIAL CURRENT. 2i)

They were obliged to run under courses, and pro- Ciur. il
cceded at the rate of ten knots, although the vessel was stoi-mv"
not a fast sailer. In the morning of the 6th she rolled weather.
so much that the fore topgallant-mast was carried away.
On the 7th they were in the latitude of Cape Finisterre,
belonging to the group of granitic rocks named the
Sierra de Torinona, which is visible at sea to the distance
of 59 miles. On the 8th at sunset, they discovered
from the mast-head an English convoy ; and to avoid
them they altered their course during the night. On
the 9th they began to feel the effect of the great
current which flows from the Azores towards the Straits
of Gibraltar and tlie Canaries. Its direction was at
first east by south ; but nearer the inlet it became due
east, and its force was such as, between 37° and 30° lat.,
sometimes to carry the vessel, in twenty-four hours,
from 21 to 80 miles eastward.

Between the tropics, especially from the coast of Equmoctiaj
Senegal to the Caribbean Sea, there is a stream that '=^"^°'-
always flows from east to west, and which is named the
Equinoctial Current. Its mean rapidity may be esti-
mated at ten or eleven miles in twenty-four hours.
This movement of the waters, which is also observed in
the Pacific Ocean, having a direction contrary to that
of the earth's rotation, is supposed to be connected with Supposed
the latter only in so far as it changes into trade-winds <=™^^-
those aerial currents from the poles, which, in the
lower regions of the atmosphere, carry the cold air of
the high latitudes towards the equator ; and it is to the
general impulse which these winds give to the surface
of the ocean that the phenomenon in question is to be
attributed.

This current carries the waters of the Atlantic to- its effect
wards the Mosq\iito and Honduras coasts, from which
they move northwards, and passing into the Gulf of
Mexico follow the bendings of the shore from Vera
Cruz to the mouth of the Rio del Norte, and from
thence to the mouths of the Mississipi)i and the shoals at



2(3



GULF STHKAM.



Oiance of
cuurse.



ciiAi'. II. the southern extremity of Florida. After ])en'orming
foi.r5e"oi- this circuit, it again directs itself northward, rushing
tl.e cuiTtnt with great impetuosity througli the Straits of Bahama.
At the end of these narrows, in the parallel of Cape
Canaveral, the flow, which rushes onward like a torrent
sometimes at the rate of five miles an hour, runs to the
north-east. Its velocity diminishes and its breadth
enlarges as it proceeds northward. Between Cayo
Biscaino and the Bank of Bahama the width is only 52
miles, while in 285^ of lat. it is 5'J ; and in the parallel
of Charlestown, opposite Cape Ilenlopen, it is from 138
to 173 miles, the rapidity being from three to five
miles an hour where the stream is narrow, and only one
mile as it advances towards the north. To the east of
Boston and in the meridian of Halifax the current is
nearly 270 miles broad. Here it suddenly turns
towards the east ; its western margin touching the
extremity of the great bank of Newfoundland. From
this to the Azores it continues to flow to the E. and
E.S.E., still retaining part of the impulse which it had
received nearly 3500 miles distant in the Straits of
Florida. In the mer"dian of the Isles of Corvo and
Flores, the most western of the Azores, it is not less
tiian 552 miles in breadth. From the Azores it directs
itself towards the Straits of Gibraltar, the island of
Madeira, and the Canary Isles. To the south of Ma-
deira, we can distinctly follow its motion to the S.E.
and S.S.E. bearing on the sliores of Africa, between
Capes Cantin and Bojador. Cape Blanco, which, next
to Cape "N'erd, farther to the south, is the most promi-
nent part of that coast, seems again to influence the
direction of the stream ; and in this parallel it mixes
witii the great equinoctial current already described.

In tliis maimer the waters of the Atlantic, between
the parallels of 11° and -13°, are carried round in a
continual whirliwol, which lIuml)ol(lt calculates must
take two years and ten months to perform its circuit
of 13,1 18 miles. This great current is named the Gulf-



Clrcnlt of
tlic <fcc&n
currenta



IMARINE ANI.MALS — MEDl'S.E. 2/

stream. Off the coast of Newfoundland a branch scpa- chap, il
rates from it, and runs from S.W. to N.E. towards the
coasts of Europe.

From Corunna to 36° of latitude, our travellers had Meausae.
scarcely seen any other animals than terns (or sea-
swallows) and a few dolphins; but on the 11th June
they entered a zone in which the whole sea was covered
with a prodigious quantity of medusae. The vessel was
almost becalmed ; but the mollusca advanced towards
the south-east with a rapidity equal to four times that of
the current, and continued to pass nearly three quarters
of an hour, after which only a few scattered individuals
were seen. Among these animals they recognised the
Medusa uurita of Baster, the M. pelagica of Bosc, and a
third approaching in its characters to the M. hysocelia,
which is distinguished by its yellowish-brown colour,
and by having its tentacula longer than the body.
Several of them were four inches in diameter, and the
bright reflection from their bodies contrasted pleasantly
with the a/Aire tint of the sea.

On the morning of the 13th June, in lat. 34° 33', Daffj-sa
they observed large quantities of the Dagysa no'Mta, of ""'"'^
which several had been seen among the medusae, and
which consist of little transparent gelatinous sacs, ex-
tending to fourteen lines, with a diameter of two or
three, and open at both ends. These cylinders are
longitudinally agglutinated like the cells of a honey-
comb, and form strings from six to eight inches in length.
They observed, after it became dark, that none of the
three species of medusa which they had collected emit- ^^mission of
ted light unless they were slightly shaken. When a "^
very irritable individual is placed on a tin plate, and
the latter is struck with a piece of metal, the vibrations
of the tin are sufficient to make the animal shine.
Sometimes, on galvanizing medusae, the phosphorescence
appears at the moment when the chain closes, although
the exciters are not in direct contact with the body of
the subject. The fingers, after touching it, remain
luminous for two or three minutes. Wood, on being



28 l-ALLING STARS — SWALLOW.

CHAP IL rubbed with a medusa, becomes luminous, and after the
Phosphor- phosphorescence lias ceased it may be rekindled by
i-sience pro- passing the dry liand over it ; but when the light is a

second time extinguished it cannot be rcjjroduced.
Failing Between tlie island of Madeira and the coast of Africa,

*"'"'*■ they were struck by tlic prodigious quantity of falling

stars, which continued to increase as they advanced
soutliward. These meteors, Humboldt remarks, are
more common and more luminous in certain regions of
the earth than in others. He has nowhere seen them
more frequent than in tlie vicinity of the volcanoes of
Quito, and in tliat part of the South Sea wliicli washes
the shores of Guatimala. According to the oliservations
of Benzenberg and Brandes, many falling stars noticed

iiei«ht of in Europe were only 03,950 yards, or a little more than

meteors. . . ; , "

thirty-six miles high ; and one was measured, the ele-
vation of which did not exceed 29,843 yards, or about
seventeen miles. In warm climates, and especially
between the tropics, they often leave behind them a
train which remains luminous for twelve or fifteen
seconds. At other times they seem to burst, and se-
parate into a number of sparks. They are generally
much lower than in the north of Europe. These
meteors can be observed only when the sky is clear ;
and perhaps none has ever been seen beneath a cloud.
According to the observations of M. Arago, they usually
folluw the same course lor several hours ; and in this
case their direction is that of the wind.

SwiUow. Wlien the voyagers were 138 miles to the east of

Madeira, a common swallow {^Ilirundo rustiai) perched
on the topsail-yard, and was caught. What could
induce a bird, asks our traveller, to fly so far at this
sen'ifjn, and in cahn weather J In the ex])edition of
Entrecasteaiix, a swallow was also seen at the distance
of 207 miles i)if Cajx! Blanco ; but this liappened about
tlie end of October, and M. Labillardiere imagined that
it liad newly arrived from Juirope.

The I'iz.irro had l>een orden d to toucli at Lancerota,
one of the Canaries, to ascertain whether the harbour lA



ISLAND OF LANCKKOTA. 29

Santa Cruz in TenerifFe was blockaded by the English ; chap. II.
and on the IGth, in the afternoon, the seamen discovered , ,„,"~~»„
land, which proved to be that island. As they advanced,
tliey saw first the island of Fortevontura, famous for
the number o-f camels reared upon it, and soon after the
smaller one of Lobos, Spending part of the night on
deck, the naturalists viewed the volcanic summits ol
Lancerota illumined by the moon, and enjoyed the
beautiful serenity of the atmosphere. After a time,
great black clouds, rising behind the volcano, shrouded
at intervals the moon and the constellation of Scorpio.
They observed lights carried about on the shore, pro-
bably by fishermen, and having been employed occa-
sionally during their passage in reading some of the old
Spanish voyages, these moving fires recalled to their
imagination those seen on the island of Guanahani on
the memorable night of the discovery of the New
World.

In passing through the archipelago of small islands, Configia-
situated to the north of Lancerota, they were struck by coasts! ^^^
the configuration of the coasts, which resembled the
banks of the Rhine near Bonn. It is a remarkable cir-
cumstance, our author observes, that, while the forms
of animals and plants exhibit the greatest diversity in
different climates, the rocky masses present the same
appearances in both hemispheres. In the Canary Isles,
as in Auvergne, in the Mittelgebirge in Bohemia, in
Mexico, and on the banks of the Ganges, the trap for-
mation displays a symmetrical arrangement of the
mountains, exhibiting truncated cones and graduated
platforms.

The whole western part of Lancerota announces the Voican
character of a country recently deranged by volcanic '^"'^^^
action, every part being black, arid, and destitute of
soil. The Abbe' Viera relates, that in 1730 more than
half of the island changed its appearance. The great
volcano ravaged the most fertile and best cultivated
district, and entirely destroyed nine villages. Its erup-
tions were preceded by an earthquake, and violent



30



COI.OIR OF MARINE PLANTS.



CHAP.

Contiiiut
tion of
bliocks.



Aiicicn
Cuiianaii



Marine



Effects of
llfihL



IL sliocks coiitiniud to he felt for several j-ears, — a iilieno-
iiienon of rare occurrence, the agitation of the ground
usually ceasing after a disengagement of lava or other
volcanic products. The summit of the great crater,
called the corona, is rounded, and its height has been
accurately determined at 18(57 feet. The island of Lan-
cerota was formerly named Titeroigotra, and at the
time of the arrival of the Spaniards its inhabitants were

*• more civilized than the other Canarians, living in houses
built of hewn stone, while the Guanches of Tencritfe
resided in caves. There was then a very singular
institution in the island. The women had several
husijands, each of whom enjoyed the prerogative be-
longing to the head of a family in succession, the others
remaining for the time in the capacity of common
domestics.*

The occurrence, between the islands of Alegranza and
."^lontana Clara, of a singular marine jjroduction with
light-green leaves, which was brought up by the lead
from a great dej)th, affords our author, in his narrative,
an opportunity of stating some interesting facts respect
nig the colouring of plants. This seaweed, growing at
the bottom of the ocean at a depth of 205 feet, had its
vine-shaped leaves as green as those of our gramineffi.
According to Bouguer's experiments, light is weakened
after a piissage of 11)2 feet, in the proportion of 1 to
1477"8. At the depth of 205, this fucns could only
have had light equal to half of that supplied I)y a candle
seen at the distance of a foot. The germs of several of
the liliacea-, the embryo of the mallows and other



* A similar practice is stated by Mr Fraser, in his "Journal oJ
a Tour throiiirli tlie Himala JMoiiiitaiiis." p. 20t), to occur in seve
ral of the kil, provinces of India. " It is usual all over the coun-
try (,.r the liitui e hushaiid to purchase his wile Croni her jiarents ; and
the .sum thfis paid varies oC course with tlie rank of the purchaser.
1 he diHicuhy of laisin^' this sum, and the allcj^'ed expense of main-
lauiiiij: women, may in part account fur, if it cannot excuse, a most
di>t:nsliii^; u'Hjie, whi. Ii is universal over the country. Three or
lour .ir Miore hrolh.-rs many and cohahit with one woman, who is the
wife ..I all. They are unahle to raise the requisite sum indiviilually,
und ihus club llieir shares, and buy this one common spouse.'



LA GHACIOSA. 31

families, the branches of some subterranean phxnts, and CiiAl'. il.
vegetables transported into mines in which the air colour
contains hydrogen oi' a great quantity of azote, become witiiout
green without light. From these facts one might be '^ ' '
induced to think that the existence of carburet of iron,
which gives the green colour to the parenchyma of
plants, is not dependent upon the presence of the solar
rays only. Turner and many other botanists are of Marine
opinion that most of the seaweeds which we find floating "' - ''
on the ocean, and which in certain parts of tlie Atlantic
present the appearance of a vast inundated meadow
grow originally at the bottom of the sea, and are torn
off b}^ the waves. If this opinion be correct, the femily
of marine algs presents great difficulties to those jthy-
siologists who persist in thinking that, in all cases, the
absence of light must produce blanching.

The captain, having mistaken a basaltic rock for a Opportune
castle, saluted it, and sent one of the officers to inquire ™'''"'^'^
if the Englisli were cruising in those parts. Our
travellers took advantage of the boat to examine the
land, which they had regarded as a prolongation of the
coasts of Lancerota, but which turned out to be the
small island of La Graciosa. " Nothing," says Hum-
boldt, " can express the emotion a naturalist feels when Emotions on
for the first tune he lands in a place which is not ''^"''^"S
European. The attention is fixed upon so many ob-
jects, that one can hardly give an account of the impres-
sions which he receives. At every step he imagines
that he finds a new production ; and, in the midst of
this agitation, he often does not recognise those which
are most common in our botanical gardens and museums."
A fisherman, who, having been frightened by the firing,
had fled from them, but whom the sailors overtook,
stated that no vessels had been seen for several weeks.
The rocks of this small island were of basalt and marl,
destitute of trees or shrubs, in most places without a
trace of soil, and but scantily crusted with lichens.

The basalts are not columnar, but arranged in strata
from 10 to IG inches thick, and incline to the north-west



32



GEOLOGICAL OBSERVATIONS.



Basaltic
rocka



Different



ciiAi'. II. at an angle of 80 degrees, alternating with marl. Some
of these strata are compact, and contain large crystals of
foliated olivine, often porous, with oblong cavities, from
two to eight lines in diameter, which are coated with
calcedon y, and enclose fragments of compact basalt. The
marl, which alternates more than a hundred times witli
the trap, is of a yellowish colour, extremely friable,
very tenacious internally, and often divided into irre-
gular prisms like those of basalt. It contains much
lime, and effervesces strongly with muriatic acid. The
travellers had not time to reach the summit of a hill, the
base of which was formed of clay, with layers of basalt
resting on it, precisely as in the Scheibenberger Huegel
of Saxony. These rocks were covered with hyalite, of
which they procured several fine specimens, leaving
masses eight or ten inches square untouched.

On the shore there were two kinds of sand, the one
l)lack and basaltic, the other white and quartzy. Ex-
posed to the sun's rays the thermometer rose in the
former to 12-i-2°, aitd in the latter to 10-4° ; while in the
shade the temperature of the air was 81'8°, being 13'5°
higher than the sea air. The quartzy sand contains
fragments of felspar. Pieces of granite have been olj-
served at Teneriffe ; and the island of Gomera, according
to M. Broussonet, contains a nucleus of mica-slate.
From these facts lIuml)oldt infers, that, in the Canaries
as in the Andes of Quito, in Anvcrgne, Greece, and most
])arts of the globe, the subterranean fires have made their
way through i)rimitivc rocks.

Having re-embarked, they hoisted sail, and cndea-
vnured to get out again by the strait whicli separates
Alcgranza from Montana Clara; but, the wind having
fallen, tlie currents drove them close upon a rock marked
in old ciiarts I)y the name of Infierno, and in modern
ones under that of Roca del Oeste, — a basaltic mass



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