adjusted, packed, and most liberally placed at my disposal by Mr.
Warren De La Rue. The telescope grasped the whole of the sun, and a
considerable portion of the space surrounding it. But it would not
take in the extreme limits of the corona. For this I had lashed on to
the large telescope a light but powerful instrument, constructed by
Ross, and lent to me by Mr. Huggins. I was also furnished with an
excellent binocular by Mr. Dallmeyer. In fact, no man could have been
more efficiently supported.
It required a strict parcelling out of the interval of totality to
embrace in it the entire series of observations. These, while the sun
remained visible, were to be made with an unsilvered diagonal
eye-piece, which reflected but a small fraction of the sun's light,
this fraction, being still further toned down by a dark glass. At the
moment of totality the dark glass was to be removed, and a silver
reflector pushed in, so as to get the maximum of light from the corona
and prominences The time of totality was distributed as follows:
1. Observe approach of shadow through the air: totality.
2. Telescope 30 seconds.
3. Finder 30 seconds.
4. Double image prism 15 seconds.
5. Naked eye 10 seconds.
6. Finder or binocular 20 seconds.
7. Telescope 20 seconds.
8. Observe retreat of shadow.
In our rehearsals Elliot stood beside me, watch in hand, and
furnished with a lantern. He called out at the end of each interval,
while I moved from telescope to finder, from finder to polariscope,
from polariscope to naked eye, from naked eye back to finder, from
finder to telescope, abandoning the instrument finally to observe the
retreating shadow. All this we went over twenty times, while looking
at the actual sun, and keeping him in the middle of the field. It was
my object to render the repetition of the lesson so mechanical as to
leave no room for flurry, forgetfulness, or excitement. Volition was
not to be called upon, nor judgment exercised, but a well-beaten path
of routine was to be followed. Had the opportunity occurred, I think
the programme would have been strictly carried out.
But the opportunity did not occur. For several days the weather had
been ill-natured. We had wind so strong As to render the hawsers at
the stern of the "Urgent" as rigid as iron, and to destroy the
navigating lieutenant's sleep. We had clouds, a thunder-storm, and
some rain. Still the hope was held out that the atmosphere would
cleanse itself, and if it did we were promised air of extraordinary
limpidity. Early on the 22nd we were all at our posts. Spaces of
blue in the early morning gave us some encouragement, but all depended
on the relation of these spaces to the surrounding clouds. Which of
them were to grow as the day advanced? The wind was high, and to
secure the steadiness of my instrument I was forced to retreat behind
a projection of the bastionet, place stones upon its stand, and,
further, to avail myself of the shelter of a sail. My practised men
fastened the sail at the top, and loaded it with boulders at the
bottom. It was tried severely, but it stood firm.
The clouds and blue spaces fought for a time with varying success. The
sun was bidden and revealed at intervals, hope oscillating in
synchronism with the changes of the sky. At the moment of first
contact a dense cloud intervened; but a minute or two afterwards the
cloud had passed, and the encroachment of the black body of the moon
was evident upon the solar disk. The moon marched onward, and I saw
it at frequent intervals; a large group of spots were approached and
swallowed up. Subsequently I caught sight of the lunar limb as it cut
through the middle of a large spot. The spot was not to be
distinguished from the moon, but rose like a mountain above it. The
clouds, when thin, could be seen as grey scud drifting across the
black surface of the moon; but they thickened more and more, and made
the intervals of clearness scantier. During these moments I watched
with an interest bordering upon fascination the march of the silver
sickle of the sun across the field of the telescope. It was so sharp
and so beautiful. No trace of the lunar limb could be observed beyond
the sun's boundary. Here, indeed, it could only be relieved by the
corona, which was utterly cut off by the dark glass. The blackness of
the moon beyond the sun was, in fact, confounded with the blackness of
space.
Beside me was Elliot with the watch and lantern, while Lieutenant
Archer, of the Royal Engineers, had the kindness to take charge of my
note-book. I mentioned, and he wrote rapidly down, such things as
seemed worthy of remembrance. Thus my hands and mind were entirely
free; but it was all to no purpose. A patch of sunlight fell and
rested upon the landscape some miles away. It was the only
illuminated spot within view. But to the north-west there was still a
space of blue which might reach us in time. Within seven minutes of
totality another space towards the zenith became very dark. The
atmosphere was, as it were, on the brink of a precipice, being charged
with humidity, which required but a slight chill to bring it down in
clouds. This was furnished by the withdrawal of the solar beams: the
clouds did come down, covering up the space of blue on which our hopes
had so long rested. I abandoned the telescope and walked to and fro
in despair. As the moment of totality approached, the descent towards
darkness was as obvious as a falling stone. I looked towards a
distant ridge, where the darkness would first appear. At the moment a
fan of beams, issuing from the hidden sun, was spread out over the
southern heavens. These beams are bars of alternate light and shade,
produced in illuminated haze by the shadows of floating cloudlets of
varying density. The beams are practically parallel, but by an effect
of perspective they appear divergent, having the sun, in fact, for
their point of convergence. The darkness took possession of the ridge
referred to, lowered upon M. Janssen's observatory, passed over the
southern heavens, blotting out the beams as if a sponge had been drawn
across them. It then took successive possession of three spaces of
blue sky in the south-eastern atmosphere. I again looked towards the
ridge. A glimmer as of day-dawn was behind it, and immediately
afterwards the fan of beams, which had been for more than two minutes
absent, revived. The eclipse of 1870 had ended, and, as far as the
corona and flames were concerned, we had been defeated.
Even in the heart of the eclipse the darkness was by no means perfect.
Small print could be read. In fact, the clouds which rendered the day
a dark one, by scattering light into the shadow, rendered the darkness
less intense than it would have been had the atmosphere been without
cloud. In the more open spaces I sought for stars, but could find
none. There was a lull in the wind before and after totality, but
during the totality the wind was strong. I waited for some time on
the bastionet, hoping to get a glimpse of the moon on the opposite
border of the sun, but in vain. The clouds continued, and some rain
fell. The day brightened somewhat afterwards, and, having packed all
up, in the sober twilight Mr. Crookes and myself climbed the heights
above the fort of Vera Cruz. From this eminence we had a very noble
view over the Mediterranean and the flanking African hills. The
sunset was remarkable, and the whole outlook exceedingly fine.
The able and well-instructed medical officer of the "Urgent," Mr.
Goodman, observed the following temperatures during the progress of
the eclipse:
Hour Deg.
11.45 56
11.55 55
12.10 54
12.37 53
12.39 52
12.43 51
1.5 52
1.27 53
1.44 56
2.10 57
The minimum temperature occurred some minutes after totality, when a
slight rain fell.
The wind was so strong on the 23rd that Captain Henderson would not
venture out. Guided by Mr. Goodman, I visited a cave in a remarkable
stratum of shell-breccia, and, thanks to my guide, secured specimens.
Mr. Busk informs me that a precisely similar breccia, is found at
Gibraltar, at approximately the same level. During the afternoon,
Admiral Ommaney and myself drove to the fort of Marsa el Kibir. The
fortification is of ancient origin, the Moorish arches being still
there in decay, but the fort is now very strong. About four or five
hundred fine-looking dragoons were looking after their horses, waiting
for a lull to enable them to embark for France. One of their officers
was wandering in a very solitary fashion over the fort. We had some
conversation with him. He had been at Sedan, had been taken prisoner,
but had effected his escape. He shook his head when we spoke of the
termination of the war, and predicted its long continuance. There was
bitterness in his tone as he spoke of the charges of treason so
lightly levelled against French commanders.
The green waves raved round the promontory on which the fort stands,
smiting the rocks, breaking into foam, and jumping, after impact, to a
height of a hundred feet and more into the air. As we returned our
vehicle broke down through the loss of a wheel. The Admiral went on
board, while I remained long watching the agitated sea. The little
horses of Oran well merit a passing word. Their speed and endurance,
both of which are heavily drawn upon by their drivers, are
extraordinary.
The wind sinking, we lifted anchor on the 24th. For some hours we
went pleasantly along; but during the afternoon the storm revived, and
it blew heavily against us all the night. When we came opposite the
Bay of Almeria, on the 25th, the captain turned the ship, and steered
into the bay, where, under the shadow of the Sierra Nevada, we passed
Christmas night in peace. Next morning 'a rose of dawn' rested on the
snows of the adjacent mountains, while a purple haze was spread over
the lower hills. I had no notion that Spain possessed so fine a range
of mountains as the Sierra Nevada. The height is considerable, but
the form also is such as to get the maximum of grandeur out of the
height. We weighed anchor at eight A.M., passing for a time through
shoal water, the bottom having been evidently stirred up. The
adjacent land seemed eroded in a remarkable manner. It has its
floods, which excavate these valleys and ravines, and leave those
singular ridges behind. Towards evening I climbed the mainmast, and,
standing on the cross-trees, saw the sun set amid a blaze of fiery
clouds. The wind was strong and bitterly cold, and I was glad to
slide back to the deck along a rope, which stretched from the
mast-head to the ship's side. That night we cast anchor beside the
Mole of Gibraltar.
On the morning of the 27th, in company with two friends, I drove to
the Spanish lines, with the view of seeing the rock from that side. It
is an exceedingly noble mass. The Peninsular and Oriental mail-boat
had been signalled and had come. Heavy duties called me homeward, and
by transferring myself from the "Urgent" to the mail-steamer I should
gain three days. I hired a boat, rowed to the steamer, learned that
she was to start at one, and returned with all speed to the "Urgent."
Making known to Captain Henderson my wish to get away, he expressed
doubts as to the possibility of reaching the mail-steamer in time.
With his accustomed kindness, he however placed a boat at my disposal.
Four hardy fellows and one of the ship's officers jumped into it; my
luggage, hastily thrown together, was tumbled in, and we were
immediately on our way. We had nearly four miles to row in about
twenty minutes; but we hoped the mail-boat might not be punctual. For
a time we watched her anxiously; there was no motion; we came nearer,
but the flags were not yet hauled in. The men put forth all their
strength, animated by the exhortations of the officer at the helm.
The roughness of the sea rendered their efforts to some extent
nugatory: still we were rapidly approaching the steamer. At length
she moved, punctual almost to the minute, at first slowly, but soon
with quickened pace.
We turned to the left, so as to cut across her bows. Five minutes'
pull would have brought us up to her. The officer waved his cap and I
my hat. 'If they could only see us, they might back to us in a
moment.' But they did not see us, or if they did, they paid us no
attention. I returned to the "Urgent," discomfited, but grateful to
the fine fellows who had wrought so hard to carry out my wishes.
Glad of the quiet, in the sober afternoon I took a walk towards Europa
Point. The sky darkened and heavy squalls passed at intervals.
Private theatricals were at the Convent, and the kind and courteous
Governor had sent cards to the eclipse party. I failed in my duty in
not going. St. Michael's Cave is said to rival, if it does not
outrival, the Mammoth Cave of Kentucky. On the 28th Mr. Crookes, Mr.
Carpenter, and myself, guided by a military policeman who understood
his work, explored the cavern. The mouth is about 1,100 feet above
the sea. We zigzagged up to it, and first were led into an aperture
in the rock, at some height above the true entrance of the cave. In
this upper cavern we saw some tall and beautiful stalactite pillars.
The water drips from the roof charged with bicarbonate of lime.
Exposed to the air, the carbonic acid partially escapes, and the
simple carbonate of lime, which is hardly at all soluble in water,
deposits itself as a solid, forming stalactites and stalagmites. Even
the exposure of chalk or limestone water to the open air partially
softens it. A specimen of the Redbourne water exposed by Professors
Graham, Miller, and Hofmann, in a shallow basin, fell from eighteen
degrees to nine degrees of hardness. The softening process of Clark
is virtually a hastening of the natural process. Here, however,
instead of being permitted to evaporate, half the carbonic acid is
appropriated by lime, the half thus taken up, as well as the remaining
half, being precipitated. The solid precipitate is permitted to sink,
and the clear supernatant liquid is limpid soft water.
We returned to the real mouth of St. Michael's Cave, which is entered
by a wicket. The floor was somewhat muddy, and the roof and walls
were wet. We soon found ourselves in the midst of a natural temple,
where tall columns sprang complete from floor to roof, while incipient
columns were growing to meet each other, upwards and downwards. The
water which trickles from the stalactite, after having in part yielded
up its carbonate of lime, falls upon the floor vertically underneath,
and there builds the stalagmite. Consequently, the pillars grow from
above and below simultaneously, along the same vertical. It is easy
to distinguish the stalagmitic from the stalactitic portion of the
pillars. The former is always divided into short segments by
protuberant rings, as if deposited periodically, while the latter
presents a uniform surface. In some cases the points of inverted
cones of stalactite rested on the centres of pillars of stalagmite.
The process of solidification and the consequent architecture were
alike beautiful.
We followed our guide through various branches and arms of the cave,
climbed and descended steps, halted at the edges of dark shafts and
apertures, and squeezed ourselves through narrow passages. From time
to time we halted, while Mr. Crookes illuminated with ignited
magnesium wire, the roof, columns, dependent spears, and graceful
drapery of the stalactites. Once, coming to a magnificent cluster of
icicle-like spears, we helped ourselves to specimens. There was some
difficulty in detaching the more delicate ones, their fragility was so
great. A consciousness of vandalism, which smote me at the time,
haunts me still; for, though our requisitions were moderate, this
beauty ought not to be at all invaded. Pendent from the roof, in
their natural habitat, nothing can exceed their delicate beauty; they
_live_, as it were, surrounded by organic connections. In London they
are curious, but not beautiful. Of gathered shells Emerson writes:
I wiped away the weeds and foam,
And brought my sea-born treasures home
But the poor, unsightly, noisome things
Had left their beauty on the shore,
With the sun, and the sand, and the wild uproar.
The promontory of Gibraltar is so burrowed with caverns that it has
been called the Hill of Caves. They are apparently related to the
geologic disturbances which the rock has undergone. The earliest of
these is the tilting of the once horizontal strata. Suppose a force
of torsion to act upon the promontory at its southern extremity near
Europa Point, and suppose the rock to be of a partially yielding
character; such a force would twist the strata into screw-surfaces,
the greatest amount of twisting being endured near the point of
application of the force. Such a twisting the rock appears to have
suffered; but instead of the twist fading gradually and uniformly off,
in passing from south to north, the want of uniformity in the material
has produced lines of dislocation where there are abrupt changes in
the amount of twist. Thus, at the northern end of the rock the dip to
the west is nineteen degrees; in the Middle Hill, it is thirty-eight
degrees; in the centre of the South hill, or Sugar Loaf, it is
fifty-seven degrees. At the southern extremity of the Sugar Loaf
strata are vertical, while farther to the south they actually turn
over and dip to the east.
The rock is thus divided into three sections, separated from each
other by places of dislocation, where the strata are much wrenched and
broken. These are called the Northern and Southern Quebrada, from the
Spanish 'Tierra Quebrada,' or broken ground. It is at these places
that the inland caves of Gibraltar are almost exclusively found. Based
on the observations of Dr. Falconer and himself, an excellent and most
interesting account of these 'caves, and of the human remains and
works of art which they contain, was communicated by Mr. Busk to the
meeting of the Congress of Prehistoric Archaeology at Norwich, and
afterwards printed in the 'Transactions' of the Congress. [Footnote:
In this essay Mr. Busk refers to the previous labours of Mr. Smith, of
Jordan Hill, to whom we owe most of our knowledge of the geology of
the rock.] Long subsequent to the operation of the twisting force
just referred to, the promontory underwent various changes of level.
There are sea-terraces and layers of shell-breccia along its flanks,
and numerous caves which, unlike the inland ones, are the product of
marine erosion. The Ape's Hill, on the African side of the strait,
Mr. Busk informs me has undergone similar disturbances. [Footnote: No
one can rise from the perusal of Mr. Busk's paper without a feeling of
admiration for the principal discoverer and indefatigable explorer of
the Gibraltar caves, the late Captain Frederick Brome.]
*****
In the harbour of Gibraltar, on the morning of our departure, I
resumed a series of observations on the colour of the sea. On the way
out a number of specimens had been collected, with a view to
subsequent examination. But the bottles were claret bottles, of
doubtful purity. At Gibraltar, therefore, I purchased fifteen white
glass bottles, with ground glass stoppers, and at Cadiz, thanks to the
friendly guidance of Mr. Cameron, I secured a dozen more. These
seven-and-twenty bottles were filled with water, taken at different
places between Oran and Spithead.
And here let me express my warmest acknowledgments to Captain
Henderson, the commander of H.M.S. "Urgent," who aided me in my
observations in every possible way. Indeed, my thanks are due to all
the officers for their unfailing courtesy and help. The captain
placed at my disposal his own coxswain, an intelligent fellow named
Thorogood, who skilfully attached a cord to each bottle, weighted it
with lead, cast it into the sea, and, after three successive rinsings,
filled it under my own eyes. The contact of jugs, buckets, or other
vessels was thus avoided; and even the necessity of pouring out the
water, afterwards, through the dirty London air.
The mode of examination applied to these bottles has been already
described. [Footnote: On Dust and Disease, p. 168.] The liquid is
illuminated by a powerfully condensed beam, its condition being
revealed through the light scattered by its suspended particles. 'Care
is taken to defend the eye from the access of all other light, and,
thus defended, it becomes an organ of inconceivable delicacy.' Were
water of uniform density perfectly free from suspended matter, it
would, in my opinion, scatter no light at all. The track of a
luminous beam could not be seen in such water. But 'an amount of
impurity so infinitesimal as to be scarcely expressible in numbers,
and the individual particles of which are so small as wholly to elude
the microscope, may, when examined by the method alluded to, produce
not only sensible, but striking, effects upon the eye.'
The results of the examination of nineteen bottles filled at various
places between Gibraltar and Spithead, are here tabulated:
No. Locality Colour of Sea Appearance in Luminous beam
1 Gibraltar Harbour Green Thick with fine particles
2 Two miles Clearer green Thick with very
from Gibraltar fine particles
3 Off Cabreta Point Bright green Still thick, but less so
4 Off Cabreta Point Black-indigo Much less thick, very pure
5 Off Tarifa Undecided Thicker than No. 4
6 Beyond Tarifa Cobalt-blue Much purer than No. 5
7 Twelve miles Yellow-green Very thick
from Cadiz
8 Cadiz Harbour Yellow-green Exceedingly thick
9 Fourteen miles Yellow-green Thick, but less so
from Cadiz
10 Fourteen miles Bright green Much less thick
from Cadiz
11 Between Capes Deep Indigo Very little matter,
St. Mary and Vincent very pure
12 Off the Burlings. Strong green Thick, with fine matter
13 Beyond the Burlings Indigo Very little matter, pure
14 Off Cape Finisterre Undecided Less pure
15 Bay of Biscay Black-indigo Very little matter,
very pure
16 Bay of Biscay Indigo Very fine matter.
Iridescent
17 Off Ushant Dark green A good deal of matter
18 Off St. Catherine's Yellow-green Exceedingly thick
19 Spithead Green Exceedingly thick
Here we have three specimens of water, described as green, a clearer
green, and bright green, taken in Gibraltar Harbour, at a point two
miles from the harbour, and off Cabreta Point. The home examination
showed the first to be thick with suspended matter, the second less
thick, and the third still less thick. Thus the green brightened as
the suspended matter diminished in amount.
Previous to the fourth observation our excellent navigating
lieutenant, Mr. Brown, steered along the coast, thus avoiding the
adverse current which sets in, through the Strait, from the Atlantic
to the Mediterranean. He was at length forced to cross the boundary
of the Atlantic current, which was defined with extraordinary
sharpness. On the one side of it the water was a vivid green, on the
other a deep blue. Standing at the bow of the ship, a bottle could be
filled with blue water, while at the same moment a bottle cast from
the stern could be filled with green water. Two bottles were secured,
one on each side of this remarkable boundary. In the distance the
Atlantic had the hue called ultra-marine; but looked fairly down upon,
it was of almost inky blackness--black qualified by a trace of
indigo.