Among the plants, the most important change has been in the growth of

flowering plants, which have been constantly becoming more plenty, and

the plants which bear fruits have also become more numerous. The

broad-leaved trees seem to be constantly gaining on the forests of

narrow-leaved cone-bearers, which had in an earlier day replaced the

forests of ferns.

In these Tertiary ages, as in the preceding times of the earth, the

lands and seas were much changed in their shape. It seems that in the

earlier ages the land had been mostly in the shape of large islands

grouped close together where the continents now are. In this time,

these islands grew together to form the united lands of Europe, Asia,

Africa, Australia, and the twin American continents; so that, as life

rose higher, the earth was better fitted for it. Still there were

great troubles that it had to undergo. There were at least two

different times during the Tertiary age termed glacial periods, times

when the ice covered a large part of the northern continents,

compelling life of all sorts to abandon great regions, and to find new

places in more southern lands. Many kinds of animals and plants seem

to have been destroyed in these journeys; but these times of trial, by

removing the weaker and less competent creatures, made room for new

forms to rise in their places. All advance in nature makes death

necessary, and this must come to races as well as to individuals if

the life of the world is to go onward and upward.

Looking back into the darkened past, of which we yet know but little

compared with what we would like to know, we can see the great armies

of living beings led onward from victory to victory toward the higher

life of our own time. Each age sees some advance, though death

overtakes all its creatures. Those that escape their actual enemies or

accident, fall a prey to old age: volcanoes, earthquakes, glacial

periods, and a host of other violent accidents sweep away the life of

wide regions, yet the host moves on under a control that lies beyond

the knowledge of science. Man finds himself here as the crowning

victory of this long war. For him all this life appears to have

striven. In his hands lies the profit of all its toil and pain.

Surely this should make us feel that our duty to all these living

things, that have shared in the struggle that has given man his

elevation, is great, but above all, great is our duty to the powers

that have been placed in our bodies and our minds.

[Illustration: A GLACIER.]

THE PITCH LAKE IN THE WEST INDIES

(FROM AT LAST.)

BY C. KINGSLEY.

[Illustration: COOLIE AND NEGRO.]

The Pitch Lake, like most other things, owes its appearance on the

surface to no convulsion or vagary at all, but to a most slow,

orderly, and respectable process of nature, by which buried vegetable

matter, which would have become peat, and finally brown coal, in a

temperate climate, becomes, under the hot tropic soil, asphalt and

oil, continually oozing up beneath the pressure of the strata above

it....

* * * * *

As we neared the shore, we perceived that the beach was black with

pitch; and the breeze being off the land, the asphalt smell (not

unpleasant) came off to welcome us. We rowed in, and saw in front of a

little row of wooden houses a tall mulatto, in blue policeman's dress,

gesticulating and shouting to us. He was the ward policeman, and I

found him (as I did all the colored police) able and courteous, shrewd

and trusty. These police are excellent specimens of what can be made

of the negro, or half-negro, if he be but first drilled, and then

given a responsibility which calls out his self-respect. He was

warning our crew not to run aground on one or other of the pitch

reefs, which here take the place of rocks. A large one, a hundred

yards off on the left, has been almost all dug away, and carried to

New York or to Paris to make asphalt-pavement.

[Illustration: THE POLICE STATION.]

The boat was run ashore, under his directions, on a spit of sand

between the pitch; and when she ceased bumping up and down in the

muddy surf, we scrambled out into a world exactly the hue of its

inhabitants of every shade, from jet black to copper-brown. The

pebbles on the shore were pitch. A tide-pool close by was enclosed in

pitch; a four-eyes was swimming about in it, staring up at us; and

when we hunted him, tried to escape, not by diving, but by jumping on

shore on the pitch, and scrambling off between our legs. While the

policeman, after profoundest courtesies, was gone to get a mule-cart

to take us up to the lake, and planks to bridge its water channels,

we took a look round at this oddest of corners of the earth.

In front of us was the unit of civilization,--the police-station,

wooden, on wooden stilts (as all well-built houses are here), to

insure a draught of air beneath them. We were, of course, asked to

come in and sit down, but preferred looking about, under our

umbrellas; for the heat was intense. The soil is half pitch, half

brown earth, among which the pitch sweals in and out as tallow sweals

from a candle. It is always in slow motion under the heat of the

tropic sun; and no wonder if some of the cottages have sunk right and

left in such a treacherous foundation. A stone or brick house could

not stand here; but wood and palm-thatch are both light and tough

enough to be safe, let the ground give way as it will.

The soil, however, is very rich. The pitch certainly does not injure

vegetation, though plants will not grow actually in it. The first

plants which caught our eyes were pine-apples, for which La Brea is

famous. The heat of the soil, as well as the air, brings them to

special perfection. They grow about anywhere, unprotected by hedge or

fence; for the negroes here seem honest enough, at least toward each

other; and at the corner of the house was a bush worth looking at, for

we had heard of it for many a year. It bore prickly, heart-shaped pods

an inch long, filled with seeds coated with a red waxy pulp.

This was a famous plant--_Bixa orellana Roucou_; and that pulp was the

well-known annotto dye of commerce. In England and Holland it is used

merely, I believe, to color cheeses, but in the Spanish Main to color

human beings. The Indian of the Orinoco prefers paint to clothes; and

when he has "roucoued" himself from head to foot, considers himself in

full dress, whether for war or dancing. Doubtless he knows his own

business best from long experience. Indeed, as we stood broiling on

the shore, we began somewhat to regret that European manners and

customs prevented our adopting the Guaraon and Arrawak fashion.

[Illustration: THE MULE-CART.]

The mule-cart arrived; the lady of the party was put into it on a

chair, and slowly bumped and rattled past the corner of Dundonald

Street--so named after the old sea-hero, who was, in his life-time,

full of projects for utilizing this same pitch--and up in pitch road,

with a pitch gutter on each side.

The pitch in the road has been, most of it, laid down by hand, and is

slowly working down the slight incline, leaving pools and ruts full of

water, often invisible, because covered with a film of brown

pitch-dust, and so letting in the unwary walker over his shoes. The

pitch in the gutter-bank is in its native place, and as it spues

slowly out of the soil into the ditch in odd wreaths and lumps, we

could watch, in little, the process which has produced the whole

deposit--probably the whole lake itself.

A bullock-cart, laden with pitch, came jolting down past us, and we

observed that the lumps, when the fracture is fresh, have all a drawn

out look; that the very air bubbles in them, which are often very

numerous, are all drawn out likewise, long and oval, like the

air-bubbles in some ductile lavas.

On our left, as we went on, the bush was low, all of yellow cassia and

white Hibiscus, and tangled with lovely convolvulus-like creepers,

Ipomoea and Echites, with white, purple or yellow flowers. On the

right were negro huts and gardens, fewer and fewer as we went on,--all

rich with fruit trees, especially with oranges, hung with fruit of

every hue; and beneath them, of course, the pine-apples of La Brea.

Everywhere along the road grew, seemingly wild here, that pretty low

tree, Cashew, with rounded yellow-veined leaves and little green

flowers, followed by a quaint pink and red-striped pear, from which

hangs, at the larger and lower end, a kidney-shaped bean, which bold

folk eat when roasted; but woe to those who try it when raw; for the

acrid oil blisters the lips, and even while the beans are roasting the

fumes of the oil will blister the cook's face if she holds it too near

the fire.

As we went onward up the gentle slope (the rise is one hundred and

thirty-eight feet in rather more than a mile), the ground became more

and more full of pitch, and the vegetation poorer and more rushy,

till it resembled, on the whole, that of an English fen. An Ipomoea or

two, and a scarlet flowered dwarf Heliconia, kept up the tropic type,

as does a stiff brittle fern about two feet high. We picked the weeds,

which looked like English mint or basil, and found that most of them

had three longitudinal nerves in each leaf, and were really

Melastomas, though dwarfed into a far meaner habit than that of the

noble forms we saw at Chaguanas, and again on the other side of the

lake. On the right, too, in a hollow, was a whole wood of Groogroo

palms, gray stemmed, gray leaved, and here and there a patch of white

or black Roseau rose gracefully eight or ten feet high among the

reeds.

The plateau of pitch now widened out, and the whole ground looked like

an asphalt pavement, half overgrown with marsh-loving weeds, whose

roots feed in the sloppy water which overlies the pitch. But, as yet,

there was no sign of the lake. The incline, though gentle, shuts off

the view of what is beyond. This last lip of the lake has surely

overflowed, and is overflowing still, though very slowly. Its furrows

all curve downward; and it is, in fact, as one of our party said, "a

black glacier." The pitch, expanding under the burning sun of day,

must needs expand most toward the line of least resistance--that is,

downhill; and when it contracts again under the coolness of night, it

contracts, surely, from the same cause, more downhill than uphill; and

so each particle never returns to the spot whence it started, but

rather drags the particles above it downward toward itself. At least,

so it seemed to us. Thus may be explained the common mistake which is

noticed by Messrs. Wall and Sawkins in their admirable description of

the lake.

"All previous descriptions refer the bituminous matter scattered over

the La Brea district, and especially that between the village and the

lake, to streams which have issued at some former epoch from the lake,

and extended into the sea. This supposition is totally incorrect, as

solidification would probably have ensued before it had proceeded

one-tenth of the distance; and such of the asphalt as has undoubtedly

escaped from the lake has not advanced more than a few yards, and

always presents the curved surfaces already described, and never

appears as an extended sheet."

Agreeing with this statement as a whole, I nevertheless cannot but

think it probable that a great deal of the asphalt, whether it be in

large masses or in scattered veins, may be moving very slowly down

hill, from the lake to the sea, by the process of expansion by day and

contraction by night, and may be likened to a caterpillar, or rather

caterpillars innumerable, progressing by expanding and contracting

their rings, having strength enough to crawl down hill, but not

strength enough to back up hill again.

At last we surmounted the last rise, and before us lay the famous

lake--not at the bottom of a depression, as we expected, but at the

top of a rise, whence the ground slopes away from it on two sides, and

rises from it very slightly on the two others. The black pool glared

and glittered in the sun. A group of islands, some twenty yards wide,

were scattered about the middle of it. Beyond it rose a double forest

of Moriche fan-palms; and to the right of them high wood with giant

Mombins and undergrowth of Cocorite--a paradise on the other side of

the Stygian pool.

[Illustration: THE PITCH LAKE.]

We walked, with some misgivings, on to the asphalt, and found it

perfectly hard. In a few steps we were stopped by a channel of clear

water, with tiny fish and water-beetles in it; and, looking round, saw

that the whole lake was intersected with channels, so unlike anything

which can be seen elsewhere that it is not easy to describe them.

Conceive a crowd of mushrooms, of all shapes, from ten to fifty feet

across, close together side by side, their tops being kept at exactly

the same level, their rounded rims squeezed tight against each other;

then conceive water poured on them so as to fill the parting seams,

and in the wet season, during which we visited it, to overflow the

tops somewhat. Thus would each mushroom represent, tolerably well, one

of the innumerable flat asphalt bosses, which seem to have sprung up

each from a separate centre, while the parting seams would be of much

the same shape as those in the asphalt, broad and shallow atop, and

rolling downward in a smooth curve, till they are at bottom mere

cracks from two to ten feet deep. Whether these cracks actually close

up below, and the two contiguous masses of pitch become one, cannot be

seen. As far as the eye goes down, they are two, though pressed close

to each other. Messrs. Wall and Sawkins explain the odd fact clearly

and simply. The oil, they say, which the asphalt contains when it

rises first, evaporates in the sun, of course most on the outside of

the heap, leaving a thorough coat of asphalt, which has, generally, no

power to unite with the corresponding coat of the next mass. Meanwhile

Mr. Manross, an American gentleman, who has written a very clever and

interesting account of the lake, seems to have been so far deceived by

the curved and squeezed edges of these masses that he attributes to

each of them a revolving motion, and supposes that the material is

continually passing from the centre to the edges, when it "rolls

under," and rises again in the middle. Certainly the strange stuff

looks, at the first glance, as if it were behaving in this way; and

certainly, also, his theory would explain the appearance of sticks and

logs in the pitch. But Messrs. Wall and Sawkins say that they have

observed no such motion: nor did we; and I agree with them, that it is

not very obvious to what force, or what influence, it could be

attributable. We must, therefore, seek some other way of accounting

for the sticks--which utterly puzzled us, and which Mr. Manross well

describes as "numerous pieces of wood, which, being involved in the

pitch, are constantly coming to the surface. They are often several

feet in length, and five or six inches in diameter. On reaching the

surface they generally assume an upright position, one end being

detained in the pitch, while the other is elevated by the lifting of

the middle. They may be seen at frequent intervals over the lake,

standing up to the height of two or even three feet. They look like

stumps of trees protruding through the pitch; but their parvenu

character is curiously betrayed by a ragged cap of pitch which

invariably covers the top, and hangs down like hounds' ears on either

side."

Whence do they come? Have they been blown on to the lake, or left

behind by man? or are they fossil trees, integral parts of the

vegetable stratum below which is continually rolling upward? or are

they of both kinds? I do not know. Only this is certain, as Messrs.

Wall and Sawkins have pointed out, that not only "the purer varieties

of asphalt, such as approach or are identical with asphalt glance,

have been observed" (though not, I think, in the lake itself) "in

isolated masses, where there was little doubt of their proceeding from

ligneous substances of larger dimensions, such as roots and pieces of

trunks and branches," but, moreover, that "it is also necessary to

admit a species of conversion by contact, since pieces of wood

included accidentally in the asphalt, for example, by dropping from

overhanging vegetation, are often found partially transformed into the

material." This is a statement which we verified again and again, as

we did the one which follows, namely, that the hollow bubbles which

abound on the surface of the pitch "generally contain traces of the

lighter portion of vegetation," and "are manifestly derived from

leaves, etc., which are blown about the lake by the wind, and are

covered with asphalt, and, as they become asphalt themselves, give off

gases which form bubbles round them."

But how is it that those logs stand up out of the asphalt, with

asphalt caps and hounds' ears (as Mr. Manross well phrases it) on the

tops of them?

We pushed on across the lake, over the planks which the negroes laid

down from island to island. Some, meanwhile, preferred a steeple-chase

with water-jumps, after the fashion of the midshipmen on a certain

second visit to the lake. How the negroes grinned delight and surprise

at the vagaries of English lads--a species of animal altogether new to

them; and how they grinned still more when certain staid and portly

dignitaries caught the infection, and proved by more than one good

leap that they too had been English school-boys--alas! long, long ago.

So, whether by bridging, leaping, or wading, we arrived at the little

islands, and found them covered with a thick, low scrub; deep sedge,

and among them Pinguins, like huge pine-apples without the apple; gray

wild-pines, parasites on Matapalos, which, of course, have established

themselves, like robbers and vagrants as they are, everywhere; a true

holly, with box-like leaves; and a rare cocoa-plum, very like the

holly in habit, which seems to be all but confined to these little

patches of red earth, afloat on the pitch. Out of the scrub, when we

were there, flew off two or three night-jars, very like our English

species, save that they had white in the wings; and on the second

visit one of the midshipmen, true to the English boy's bird's-nesting

instinct, found one of their eggs, white-spotted, in a grass nest.

Passing these little islands, which are said (I know not how truly) to

change their places and number, we came to the very fountains of Styx,

to that part of the lake where the asphalt is still oozing up.

As the wind set toward us, we soon became aware of an evil

smell--petroleum and sulphureted hydrogen at once--which gave some of

us a headache. The pitch here is yellow and white with sulphur foam;

so are the water-channels; and out of both water and pitch innumerable

bubbles of gas arise, loathsome to the smell. We became aware that the

pitch was soft under our feet. We left the impression of our boots;

and if we had stood still awhile, we should soon have been ankle-deep.

No doubt there are spots where, if a man stayed long enough, he would

be slowly and horribly engulfed. "But," as Mr. Manross says truly, "in

no place is it possible to form those bowl-like depressions round the

observer described by former travellers." What we did see is that the

fresh pitch oozes out at the lines of least resistance, namely, in the

channels between the older and more hardened masses, usually at the

upper ends of them, so that one may stand on pitch comparatively hard,

and put one's hand into pitch quite liquid, which is flowing softly

out, like some ugly fungoid growth, such as may be seen in old

wine-cellars, into the water. One such pitch-fungus had grown several

yards in length in the three weeks between our first and second visit;

and on another, some of our party performed exactly the same feat as

Mr. Manross.

"In one of the star-shaped pools of water, some five feet deep, a

column of pitch had been forced perpendicularly up from the bottom. On

reaching the surface of the water it had formed a sort of

centre-table, about four feet in diameter, but without touching the

sides of the pool. The stem was about a foot in diameter. I leaped out

on this table, and found that it not only sustained my weight, but

that the elasticity of the stem enabled me to rock it from side to

side. Pieces torn from the edges of this table sank readily, showing

that it had been raised by pressure, and not by its buoyancy."

True, though strange; but stranger still did it seem to us when we did

at last what the negroes asked us, and dipped our hands into the

liquid pitch, to find that it did not soil the fingers. The old

proverb that one cannot touch pitch without being defiled happily does

not stand true here, or the place would be intolerably loathsome. It

can be scraped up, moulded into any shape you will, wound in a string

(as was done by one of the midshipmen) round a stick, and carried off;

but nothing is left on the hand save clean gray mud and water. It may

be kneaded for an hour before the mud be sufficiently driven out of it

to make it sticky. This very abundance of earthy matter it is which,

while it keeps the pitch from soiling, makes it far less valuable than

it would be were it pure.

It is easy to understand whence this earthy matter (twenty or thirty

per cent) comes. Throughout the neighborhood the ground is full, to

the depth of hundreds of feet, of coaly and asphaltic matter. Layers

of sandstone or of shale containing this decayed vegetable alternate

with layers which contain none; and if, as seems probable, the coaly

matter is continually changing into asphalt and oil, and then working

its way upward through every crack and pore, to escape from the

enormous pressure of the superincumbent soil, it must needs carry up

with it innumerable particles of the soils through which it passes.

In five minutes we had seen, handled, and smelt enough to satisfy us

with this very odd and very nasty vagary of tropic nature; and as we

did not wish to become faint and ill between the sulphureted hydrogen

and the blaze of the sun reflected off the hot black pitch, we hurried

on over the water-furrows, and through the sedge-beds to the farther

shore--to find ourselves, in a single step, out of an Inferno into a

Paradise.

[Illustration]

A STALAGMITE CAVE

(FROM THE VOYAGE OF THE CHALLENGER.)

BY SIR C. WYVILLE THOMSON, KT., LL.D., ETC.

[Illustration]

I think the Painter's Vale cave is the prettiest of the whole. The

opening is not very large. It is an arch over a great mass of débris

forming a steep slope into the cave, as if part of the roof of the

vault had suddenly fallen in. At the foot of the bank of débris one

can barely see in the dim light the deep clear water lying perfectly

still and reflecting the roof and margin like a mirror. We clambered

down the slope, and as the eye became more accustomed to the obscurity

the lake stretched further back. There was a crazy little punt moored

to the shore, and after lighting candles Captain Nares rowed the

Governor back into the darkness, the candles throwing a dim light for

a time--while the voices became more hollow and distant--upon the

surface of the water and the vault of stalactite, and finally passing

back as mere specks into the silence.

[Illustration: A GUIDE.]

Young Folks' Library, Volume XI (of 20) Wonders of Earth, Sea and Sky · 第 6 / 23 段