The Press.
London, England, 1858-02-13 00:00:00

THE PRESS, FEBRUARY 13, 1858.

covered the sea at an altitude of about 5,000
feet, while another at 3,000 feet covered the
island; between them the sea was visible
curling in foam-waves from a N.E. wind, while
on the mountain top they had only a gentle
air. The view was "grand and soul-inspiring."
The colours of even distant mountains ap-
peared "as vivid and pure " as on the ground
close by, while the shadows are so dark and
yet so transparent, "so black-looking amid
" the sun lit landscape, and yet in reaity so
" richly and deeply coloured, that a full idea
" can only be formed, by combining what the
" telescope reveals of the powerful lights and
" shadows in the moon, with the paintings of
" Turner and of Rembrandt." " Each mo-
" men t," writes the Professor in a burst of
natural enthusiasm, "on a day of this sort is
" worth hours on any other ; we look at every-
" thing far and near, see it as it were face to
" face, and gain a higher idea of the glorious
" creation in which we live ":
As the sun descends, the shadow of Guajara is thrown
first on the sea, then on the cloud-plain ; and then as the
sun actually sets, the shadow crosses the island of Gland
Canary, rises into the sky above it, and appears distinct
and pronounced as a real mountain; and when presently,
almost behind the sharply defined summit of the shadow,
the full moon rises, and appears to be the very cause of it,
the illusion is extraordinary indeed. . . . . .

Turn round quickly though, lest you lose the glories of
the west ; ses. how vivid atmospheric colours can be, when
there are no impurities in the air. The chief part of the
light is yellow, glorious cadmium, passing below into the
richest tint of red-orange, shove into lemon-yellow, and
then powerful rose-pink, which by degrees fadea into the
deep-blue sky above.
Underneath all this display is seen the trade-wind
cloud-plain, concealing all the distant sea, and forming the
horizon on this as on every other side. Of a delicate blue
grey, these clouds farm so level a plain, that if only a
footing could be obtained on the edge that approaches so
close to Teneriffe, one could fancy it to offer an easy walk
over to Palma, that rises on the verge of the glowing
horizon.
While still admiring this scene, night arrives ; one hour
five minutes is the observed astronomical time of the dura-
tion of twilight, but that takes account of far fainter light
than what practical persons would deem of any importance;
aud half that interval ought to see all wanderings about the
mountain terminated. Oo this particular night • larger
scope is allowed by tho glories of a full moon, which, soon
abandoning the saffron colour with which it rose, mounts
up in the sky as a disc of the purest white, and actually
seems to stand out in front of the stars, and their back-
ground of indigo blue.

There was, however, at this height a " dust
haze," which seriously interfered with astro-
nomical vision, and the Professor resolved to
try an actual ascent of the Peak, and, if possi-
ble, the establishment there of a small obser-
vatoa•y. How he laboured to achieve this end,
and how gallantly he encountered and over-
came all obstacles, our readers will find de
tailed in this volume. Suffice it to say that he
scaled the central cone with undaunted ardour,
and established himself, and soon afterwards
Pattinson's Equatorial telescope, in a bed of
obsidian on the Great Crater, at a height
of some 11,000 feet above the sea level, and
within a few hundred feet of the sharp-pointed
peak of this majestic mountain, which, rising
straight from the ocean to its prodigious eleva-
tion, stands in I-me grandeur towering above
the clouds into the heavens beyond.
We have scarcely left.ourselves room to speak
of the scientific results of the expedition.
In a paper read before the Royal Society on 3rd
June, 1557, and reprinted in the Philosophical
Transactions, they will be found. The present
volume details more the personal experiences
under which those observations were made,
yet some very interesting scientific results aro
stated. Upon the top of the Guajara the
maximum heat of solar radiation was esti-
mated—for from the insufficiency of the instru-
ment it co rld not be calculated—at 212 deg.
4 min , the temperature in the shade being
only 60 deg., thus leaving l 3 deg. for the
effect of sunshine at an elevation of t+,900 feet.
From this Professor Smyth argues that the
higher we ascend, though the lower the tem-
perature, the greater the solar radiation :
Amongst those who have not thought much on radiation,
there has arisen au idea, that the closer we go to the sun
the less heat do we receive from that great luminary.
Consequently, they allege, a comet—which like that of
154:3 passed at its perihelion within 80,000 miles of the
surface of the sun—must have suffered rather from cold,
the cold of space, than from the excessive heat which
astronomers have described ; and the circumstance of per-
petual snow on the top of our loftiest mountains is pointed
to as an illustration of the case. Such snow however, and
its perpetuity, are rather to be taken as proofs of tempera-
► ture, and of the non-conductive powers of frozen water,

than of radiation; and this latter quality we invariably
found on Guajara to be the opposite of temperature ; i.e.
the days in the which temperature iu the shade was loweat,
and we may add when the air was most clear and trails.
parent, were precisely the days of highest radiation. With
the increase, on the ()tiler hand, of our too frequent visitors,
the banks of dust•haze, the height of a thermometer in the
shade increased ; while another exposed to the sun's rays
invariably decreased.

Were it possible to ascend fifty miles above the earth's
surface, and so escape altogether from its atmosphere, the
temperature of shade might fall to 50 deg., but that of
solar exposure, or radiation, would be increased probably
some hundreds of degrees, though we had not sensibly
altered our distance from the sun.

An attempt to obtain instrumental evidence
of the moon's radiation was not so satisfactory.
On one peculiarly fine, still night, radiation
was evident to the extent only of about a third
of a degree—according to experiment, just
one-third " that of an ordinary candle " at a
distance of fifteen feet. The results of the
experiments for zodiacal light are too long to
enter upon here; but we may observe that
they completely overthrow the theory of the
American Japan surveyors, who started the
theory that the light encircles not the sun bat
the earth. Mr. Smyth, as the result of his
careful observation, declares the human eyo
in his position would have been " unable to
" appreciate anything so inconceivably faint
" as must he a lunar analogue of the solar zo-
" diacal light, supposing the latter for a moment
" to depend on the sun illuminating a nebulous
" ring, encircling not himself but the earth."
The famous " lateral oscillation of stars," ob-
served by Humboldt on th• Alta Vista in
1799, was never seen by Professor Smyth in
the whole course of his two mouths' observa-
tions He regards the phenomenon related by
Humboldt as entirely exceptional, "even on
" the mountain where it was observed."

The geologist, also, will find observations of
great interest upon the graver physical fea-
tures of the Peak—upon the ages of lava
streams, upon lava caverns, and upon other
volcanic phenomena rare in occurrence and
problematical in character. The central cone
of the Peak of Teneriffe, Professor Swyth
maintains, exhibits secular and periodical
qualities coexistent :

Examination of the slums which have been sent forth
within the memory of man would tell little of secular pro-
gression; for they only break out about once a century,
the last eruption having occurred in 1798 and the previous
one in 1703 ; and it is necessary, therefore, to question,
as we have done, pre-historic phenomena. This method
at once enables us to take up a far more powerful position ;
for what a mighty period must have elapsed to include
alone the thousands of black streams which now seam thu
cone on every side; and finding many of these, that are
quite beyond the memory of man, untouched by any
oxidating influence—we are inclined to wonder what
myriads of ages must have further elapsed to produce the
deep red and yellow decompositions, so conspicuous on the
surface of still earlier streams. For their blocks are, in
the interior, black ; and in chemical composition very
similar to the substances last ejected.
We have here at all events, whatever the absolute dates,
results from an immense duration of periodical effects
spread before our eyes; and cannot resist the conclusion
which their forms set forth, viz., that a most marked
secular change has been wrought out, and that its signs are
visible still. Hence, we may state RS the general law,
holding good on the whole, not of course in every indi-
vidual instance any more than that the tide-wave advances
uniformly, and without little undulations on its surface,
that the earlier streams were the most copious and most
fluid ; nay, we may pretty safely add, the hottest also, and
that there has been a continual decrease in size and beat
ever since. The Peak of Teneriffe has, in fact, been
s eadily burning out for ages; and is, happily for inaukind,
no longer in its youthful energy, nor in its primeval vigour
of destructive power.

The ascent to the top of the Peak ought not
to be spoken of as difficult " by any man tra.
yeller," says the learned Professor ; but eager
aspirants to crown the Peak must remember
this is the opinion of a saran in pursuit of a
crater, and to such a man, under such circum-
stances, loose pumice and lava crags, to say
nothing of holes and cracks and sulphurcous
vapours, are pleasant stimulants to the pur-
suit of science. But let us hasten with the
Professor to the top of the crater:—
Fagli !—on inhaling the first whiff one was inclined to
beat an instant retreat for a few steps ; looking for the
moment with infinite disgust ou the whole mountain, as
nothing more than the chimney,
12,200 feet high, of one
of Nature's chemical inanufsctories. This chimney
haying been built at great expense, she was resolved to
turn it to account. We, curiously foolish creatures, bad
been innocently creeping up the sides; and were now
astonished to find, on peering over the mouth of the long
stalk, that noisome fumes were ascending from it
The north-eastern, northern, and north-western were
the highest, whitest, and betted', parts of the crater walls