ANOTHER EPOCH OF WORK AND TRAVEL.
Very soon after their arrival in England the travellers went north to
Kinnordy, where they remained till the end of October, when they
returned again to their London home. Such an accumulation of specimens
and of notes as had been gathered in America made necessary a long
period of labour indoors, unpacking, classifying, and arranging; while
certain groups of fossils had to be repacked and sent to friends, who
had undertaken to work them out. These occupations apparently detained
Lyell in London till August, 1843, when he started for Ireland,
indulging himself on the way with a short run in Somersetshire for some
geological work around Bath and Bristol, examining more particularly the
"dolomitic conglomerate," a shore deposit of Keuper age, in which the
remains of saurians had been found, and the Radstock Collieries, where
he spent more than five hours underground "traversing miles of galleries
in the coal," and finding here, as he had done in America, the stumps of
trees in an upright position and shales full of fossil ferns as "roofs"
to the seams. Then, in company with Mrs. Lyell, he crossed over to Cork,
where the British Association assembled on August 17th, under the
presidency of the late Earl of Rosse. The meeting was well attended by
scientific men, but was coldly received by the neighbourhood and
county--partly, as Lyell says, because the gentry cared little for
science; partly because the townspeople, comprising many rich merchants
and most of the tradesmen, were "Repealers"; "and, the agitation having
occurred since we were invited, the opposite parties could never, in
Ireland, act or pull together."
It was impossible to visit Cork without seeing the beauties of the lakes
and mountains of Killarney; and after this a short stay was made at Birr
Castle, Lord Rosse's pleasant home at Parsonstown. The huge reflecting
telescope, which is now more than a local wonder, was not then
completed; but the smaller one, itself on a gigantic scale, was in full
working order, and already had led to grand results by "not only
reducing nebulae into clusters of distinct stars, but by showing that the
regular geometric figures in which they presented themselves to
Herschel, when viewed with a glass of less power, disappear and become
very much like parts of the Milky Way." Thence they went northward to
the coast of Antrim, to see the waves breaking upon the colonnades of
basalt at the Giant's Causeway, and the dykes of that rock cutting
through and altering the white chalk. Evidently the geology proved
interesting, as well it might, for here Nature presents a volume of her
geological history, that of the Secondary era, with only the opening and
the concluding chapters, all the record from the early part of the Lias
to the beginning of the Cretaceous having been torn out. The dark-tinted
greensand, changing almost immediately into the pure white chalk, often
presents curious colour-contrasts in a single section; while the
classification of the several deposits offered a problem at which
probably Lyell thought it wiser to "look and pass on." Several of the
more interesting facts observed during this trip were afterwards
described in the "Elements of Geology,"[105] among them the beds of
lignite which occur in Antrim, associated with the great flows of
basalt. Somewhat similar deposits were found, about seven years later,
at Ardtun, in Mull, by the Duke of Argyll--a discovery which led Lyell
to suggest, in later editions of the above-named work, the probability
that the basalts of Antrim and of the Inner Hebrides were of the same
geological age,--an inference which since then has been abundantly
confirmed by the researches of Professor Judd and other geologists.
One of the most interesting sections in Scotland faces Antrim. Here, on
the Ayrshire coast, between Girvan and Ballantrae, a complex of several
kinds of igneous rock and a region, not a little disturbed, of
"greywackes" and other sedimentary deposits present the geologist with
problems more than sufficiently perplexing. At these Lyell took the
opportunity of glancing, but a day's trip afforded no opportunity for
any serious attempt to read the riddle. That had to be left to a later
generation, and so it remained for over forty years. Something is now
known about the igneous rocks, though here work still remains to be
done; and the sedimentary deposits have been brought into order by the
labours of Professor Lapworth. They exhibit, according to his
description,[106] an ascending succession from the Llandeilo to the
Llandovery group, and appear to be more modern than some, if not all, of
the above-named igneous rocks. After their brief halt in this district
the Lyells went on to Forfarshire, and spent the rest of the autumn at
Kinnordy.
The winter was a busy time; he was writing steadily at his "Travels in
North America," and working up some of the more distinctly scientific
notes into formal papers for the Geological and other societies. Thus
occupied, more than a year slipped away, diversified only by a summer
visit to Scotland, attending the meeting of the British Association at
York, and a journey to the Haswell Colliery, Durham, together with
Faraday, as commissioners to examine into the cause of a recent
disastrous explosion, and see whether such accidents could be prevented.
Work at the "Travels in North America" took up all Lyell's spare time
during the winter, and the book was published in the earlier part of
1845.
It was only a few months old when Mr. and Mrs. Lyell again set off for
another tour in America. They left Liverpool on September 4th, and
landed at Halifax on the 17th, after a voyage diversified agreeably by
the sight of an iceberg and disagreeably by two gales. They went on at
once to Boston, and thence made a tour through the State of Maine.
During this sundry masses of drift were examined, which rested on
polished and grooved surfaces of crystalline rock, and contained the
usual shells, astarte, cardium, nucula, saxicava, etc., and in some
places a fossil fish[107] in concretionary nodules. At Portland similar
shells had been found in drifts which also contained bones both of the
bison and of the walrus. These drifts in some places attained a
thickness of 170 feet, and in them valleys 70 feet deep had been
excavated by streams. Then they went to the White Mountains, and on
approaching them Lyell did not fail to notice "on the low granite hills
many angular fragments of that rock, fifteen to twenty feet in diameter,
resting on heaps of sand." On their way they came to the Willey Slide,
where a whole family of that name had been killed nineteen years
previously in a landslip. Lyell carefully examined the scene of the
accident, in order to ascertain what effects were produced by a mass of
mud and stones as it slid over a face of rock, and found that it only
made short scratches and grooves, not long and straight furrows, like
those left by a glacier. They halted at Fabyan's Hotel near Mount
Washington, and after waiting for a favourable day reached the summit
(6,225 feet above the sea) on October 7th. It is easily accessible on
horseback.
The notes of this excursion among the mountains show that Lyell still
retained his old liking for natural history in general, for they contain
remarks on the flowers, the insects, and the birds. Some observations on
the Alpine flora of the higher summits in the White Mountains indicate
his position at that time in regard to the origin of species. He adopts
the hypothesis of 'specific centres,' viz. that "each species had its
origin in a single birthplace and spread gradually from its original
centre to all accessible spots, fit for its habitation, by means of the
power of migration given it from the first." He supposed that the plants
common to the more arctic regions and to the higher ground further south
in Europe and Northern America were dispersed by floating ice during the
glacial epoch, when the ground stood at a lower level, and that
afterwards, when the climate became warmer, they gradually mounted up
the slopes of the hills. The possibility of a migration by land is not
mentioned, though doubtless it would have been admitted, because the
evidence which he had so often studied pointed rather to a downward than
to an upward movement but he asserts with some emphasis that many living
species are older than the existing distribution of sea and land.
On his return to Boston, he had other opportunities of studying ice-worn
rocks and erratics, and from this city made an excursion to Plymouth
(Massachusetts) to see the spot where, on a mid-winter day, the Pilgrim
Fathers had landed. But even here he could not neglect the shells upon
the strand, and he records that eighteen species were collected,
one-third of which were common to Europe. Still, we may note that on
this journey rather more attention was paid than on the former to
questions political, commercial, educational, and theological, and these
occupy a larger space in the "Second Visit to the United States," which
may account for its greater popularity. For example, it contains a
sketch of the witch-finding mania in Massachusetts late in the
seventeenth century, and a whole chapter on the sea-serpent. This "hardy
perennial" had appeared in the Gulf of St. Lawrence in the previous
August and in October, 1844,[108] and had repeatedly visited the New
England coast from 1815 to 1825, when it had been seen by many credible
witnesses. Lyell appears to be satisfied that, though allowance had to
be made for exaggeration and honest misconception, some big creature
had been seen, and suggests that it may have been an exceptionally large
specimen of the basking shark.[109]
After a stay of nearly two months in Boston, they left for the south
early in December, and found a little difficulty at first, as on a
former occasion, from the slippery state of the rails. They journeyed by
Newhaven, New York, Philadelphia, and Washington to Richmond, where a
halt was made to examine the coalfield some sixteen miles to the
south-west of the city. The measures rest on the granite, filling up
inequalities on its surface, and are occasionally cut by dykes, which
produce the usual alteration in the adjacent coal. The principal seam is
from thirty to forty feet thick but the field, as a whole, reminded
Lyell most of that at St. Etienne (France), which he had visited in
1843.[110] From Richmond they went, as on the former occasion, by Weldon
to Wilmington, where the cliffs near the town yielded some Tertiary
fossils, and on Christmas morning they landed from a steamer at
Charleston.
From this city Lyell again visited the deposits near Savannah, which
contained remains of megatherium, mastodon, and other large quadrupeds,
as well as a second locality on Skiddaway Island, and then, on the last
day of the year, quitted Charleston for Darien in Georgia. Here also
were some more deposits of the same kind, while at St. Simon's Island
Lyell examined a very large Indian mound. It was a mass of shells,
chiefly of oysters, and contained flint arrow-heads, stone axes, and
fragments of Indian pottery.
Returning to Savannah, they travelled towards the north-west, by Macon
to Milledgeville. For more than 150 miles of the first part of the
journey Lyell went along the railway on a hand-car, so as to study the
cuttings and obtain the most continuous section possible of the Tertiary
deposits from the sea to the inland granite. These deposits consisted of
porcelain clays, yellow and white sands, and "burrstone," a flinty grit
used for millstones, which often was full of silicified shells and
corals, with the teeth of sharks and the bones of zeuglodon. Lyell
mentions that in the neighbourhood of Macon he saw blockhouses such as
those described by Cooper in the "Pathfinder," which twenty-five years
earlier had been used for defence against the Indians before any white
men's houses had been built in the forest.
Near Milledgeville the granite, gneiss, etc., is decomposed _in situ_ to
a considerable depth, and the rain-water, when the trees have been cut
down, quickly furrows the detrital deposits of the neighbourhood. A
remarkable instance of this action had occurred at Pomona Farm, where a
ravine 180 feet broad and 55 feet deep had been excavated in the course
of only twenty years.[111] From Milledgeville they returned to Macon,
and thence travelled westward by Columbus to Montgomery, being much
jolted in the stage-coach, but securing as a reward some Tertiary
fossils; and at the latter place they found red clays and sandstones,
which, however, were about the same age as the chalk of England. After
the coach travelling, a journey by steamer down the Alabama River to
Mobile was a welcome change, and the not unfrequent halts for cargo or
to take in wood gave opportunities for collecting fossils from the
neighbouring bluffs. One night they were startled by loud crashing
noises and the sound of breaking glass, and found that the steamer had
run foul of the trees growing on the bank. Their branches touched the
water, as the river was unusually high; and the vessel, in the darkness,
had been steered too near to the shore. Longer halts were made at
Claiborne, to collect fossils from deposits corresponding in age with
those at Bracklesham in England; and at Macon (Alabama) to visit a place
where some remarkable specimens of the zeuglodon had been discovered.
From Mobile also a long river journey was undertaken to Tuscaloosa, to
visit a coalfield which supplied the town with fuel and the materials
for gas. The field, "a southern prolongation of the great Appalachian
coalfield," is a large one, being about ninety miles long and thirty
wide, with some seams sixteen feet thick worked in open quarries. He
remarks that he made geological excursions "through forests recently
abandoned by the Indians, and where their paths may still be traced."
The strata on the Alabama River afforded a useful lesson on the
variability of lithological characters. Were it not for the fossils,
Lyell says, the Lower Cretaceous beds of loose gravel might be taken for
the newest Tertiary, the main body of the Chalk for Lias, and the soft
Tertiary limestone for the representative of the Chalk. It was
impossible to leave Mobile without seeing something of the Gulf of
Mexico; so they went in a steamer down the Alabama River to the seaside,
looked upon the muddy banks, with the shells[112] which live in them and
the quantities of drift-timber which bestrew them, and then went across
to one of the minor mouths of the Mississippi, and, passing up it,
landed at New Orleans.
This town, about 110 miles by water from the confluence of the main
channel of the Mississippi with the sea, afforded a convenient
opportunity for studying the character of the lower part of the delta of
the "Father of Waters." Such a region might be expected to supply facts
which would be helpful in the interpretation of many phenomena presented
by the coal measures. Accordingly, Lyell made one excursion to Lake
Pontchartrain, a great sheet of fresh water no great distance from both
New Orleans and the sea, and another down to the mouth of the
Mississippi. The road through the swamp to the former was constructed of
a strange material--viz. the white valves of a freshwater mollusc.[113]
These are obtained from a huge bank over a mile in length, and sometimes
about four yards in depth, at one end of the lake. How this had been
formed seemed doubtful. Possibly the shells had been piled up by the
waves during a storm; possibly there had been some slight change of
level. The lake itself is about fifteen feet below high-water mark, and
is about as many deep; but, as it receives an arm of the Mississippi,
silt is gradually raising the bottom. The sea sometimes, when impelled
by a strong south-east wind, makes its way into the lake. Among the
English coal measures--as, for instance, at Coalbrook Dale or in
Yorkshire--beds of marine shells are occasionally found intercalated
among or even associated with freshwater molluscs, without any
alteration in the general character of the beds in which they lie. How
this might occur is illustrated by Lake Pontchartrain in the swampy
alluvial delta. Here a very slight physical change might enable the sea
to take, for a time, possession of the land, and the denizens of its
water, like a band of pirates, to dispossess the usual inhabitants.
The other expedition also supplied not a few valuable facts relating to
the history of river deltas, which were afterwards supplemented as they
travelled northwards for some hundreds of miles up the river, following
its sinuous course through leagues of marshy plain, densely overgrown
with vegetation. In the seaward reaches, reed, and rush, and willow, but
above New Orleans cypresses and other timber trees, rise above the rank
herbage.
The minor channels, blocked with driftwood which formed natural rafts;
the sand-bars and mud-banks; the great curves of the river, the
"bayous"[114] and isolated pools; the natural banks built up by the
sediment arrested at flood-time by the herbage near the river brink; the
floating timber and the "snags"--all provided valuable illustrations of
the physical features of a great river delta, and supplied him with
material which afterwards was worked up into newer editions of the
"Principles" and the "Elements."
From New Orleans Lyell went by steamer to Natchez, halting on the way to
examine more closely certain localities of interest and to obtain
illustrations of how a coalfield might be formed. The bluffs of
Natchez--almost the first place where distinctly higher ground
approaches the river-side--afforded plenty of semi-fossil shells,
specifically identical with those still inhabiting the valley of the
Mississippi, but the loam in which they were embedded--a loam which
reminded him of the loess of the Rhine--also contains the remains of the
mastodon, and overlies a clay with bones of the megalonyx, horse, and
other quadrupeds, mostly extinct. Beneath this clay are sands and
gravel, the whole forming a platform which rises about 200 feet above
the low river plain, revealing an earlier chapter in the history of the
river. Similar bluffs occur at Vicksburg, but these disclosed Eocene
strata beneath the alluvial deposits, and thus invited a halt in order
to explore the neighbourhood. The next stage was to Memphis, nearly 400
miles. Lyell speaks highly of the accommodation generally afforded by
the river steamers, but found the inquisitiveness of his American
fellow-travellers rather a nuisance, and the spoiled children a still
greater one. The former drawback to pleasure has certainly abated during
the last half-century, but whether the latter has done the same may
perhaps be disputed. New Madrid, 170 miles above Memphis, called for a
longer halt, for the neighbouring district had suffered from a great
earthquake in the year 1811, when shocks were felt at intervals for
about three months, the ground was cracked, water mingled with sand was
spouted out, yawning fissures opened (in one case draining a lake),
portions of the river cliff were shaken down into the stream, and a
large district--about 2,000 square miles in area--was permanently
depressed. Some traces of the earthquake, in addition to the last-named,
could still be recognised at the time of Lyell's visit, though more than
thirty years had elapsed.
At Cairo, above New Madrid, the Ohio joins the Mississippi, and it was
ascended to Mount Vernon. The geology now became a little more varied,
for beneath the shelly loam already mentioned Carboniferous strata make
their appearance, in which fossil plants are sometimes abundant and
upright trees now and then occur. For nearly 200 miles higher up the
Ohio, rocks of this age are exposed at intervals, till at last, near
Louisville, those belonging to the Devonian system rise from beneath
them. These, at New Albany, contain a fossil coral-reef, exposed in the
bed of the river and crowded with specimens in unusually good
preservation. At Cincinnati the travellers came at last upon old ground,
and journeyed thence by steamer to Pittsburg. About thirty-two miles
from this town, at a place called Greensburg, some remarkable footprints
had been discovered on slabs of stone not many months before Lyell's
visit, but as the beds on which they occurred belonged to the coal
measures doubt had been expressed as to their being genuine, so he went
thither to satisfy himself on this point. The footprints had disturbed
the peace of Pittsburg, for they had started discussions in which one
party had assumed, as matters of course, the high antiquity of the
earth and the great changes in its living tenants, and had thus incurred
the censure--which in some cases was followed by professional
injury--not only of the multitude, but also of some of the Roman
Catholic and Lutheran clergy. Commenting on this episode, Lyell quotes
with approbation the words of a contemporary author,[115] which even at
the present time occasionally need to be remembered:--"To nothing but
error can any truth be dangerous; and I know not where else there is to
be seen so altogether tragical a spectacle, as that religion should be
found standing in the highways to say 'Let no man learn the simplest
laws of the universe, lest they mislearn the highest. In the name of God
the Maker, who said, and hourly yet says, "Let there be light," we
command that you continue in darkness!'"
The travellers crossed the Alleghany Mountains in their way to
Philadelphia. But a piece of work in Virginia had been left unfinished
on the last occasion--the examination of the Jurassic coalfield near
Richmond. So he set off thither, leaving Mrs. Lyell in Philadelphia, and
took the opportunity of examining the Tertiary deposits near the former
town and the Eocene strata on the Potomac River. On his return they went
to Burlington, which they reached in the first week in May, just as the
humming-birds were arriving in hundreds, and by the 7th of the month
they were in New York. The age of the so-called Taconic Group--a
question of which so much has been heard of late years--was then
beginning to attract attention, so Lyell went in company with some
American geologists to Albany in the hope of solving the problem. This
he trusted he had done, but as his conclusions now would be deemed
unsatisfactory, they need not be quoted. In reality, the question at
that time was not even ripe for discussion.
On the homeward journey he turned aside at Boston to visit Wenham Lake,
from which much ice was being supplied to London, and then they left for
England by a steam packet which touched at Halifax. Four days after
leaving this place they passed among a "group of icebergs several
hundreds in number, varying in height from 100 to 200 feet," many of
them picturesque in form, some even fantastic. Stones were resting on
one of them, but as a rule they were perfectly clean and dazzlingly
white, except on the wave-worn parts, which, as usual, were a beautiful
blue. These, and a fine aurora borealis on the next night, were the only
incidents of the voyage, and on June 13th, in twelve and a half days
from Boston, the vessel reached Liverpool.
The close of this journey marks an epoch in Lyell's life. It was the
last--unless we except his visit to Madeira--of his long wanderings for
the purpose of questioning Nature face to face, and of studying her
under various aspects and diverse conditions. He did not, indeed, cease
to travel. He twice returned to America, he revisited Sicily and various
parts of Europe, but these journeys not only occupied less time but also
led him among scenes for the most part not unfamiliar. He doubtless felt
that on reaching his fiftieth year he might fairly regard the more
laborious part of his education completed, although he never ceased to
be a learner, even to the latest days of his life, when strength had
failed and memory was becoming weak.
An account of the above-named journey was published in 1849, under the
title of "A Second Visit to the United States of North America." This
book, in addition to descriptions of the scenery and the geology of the
country, contains much general information about the people, with
remarks by the author on various political questions, such as the
condition of parties, the effects of almost universal suffrage,
particularly on the national sense of honour and morality, the existence
and evils of slavery, the state of religious feeling, the position of
Churches, and the systems of education, especially when contrasted with
those of England. Some of these questions about this time were exciting
much attention in Great Britain, and in regard to one matter--the
delimitation of the territories of the two nations in the region west of
the Rocky Mountains--friction existed, which was so serious that more
than once war seemed possible. On this account, probably, the "Second
Visit" was a greater success, commercially speaking, than the "Travels,"
for it reached a third edition.
FOOTNOTES:
[105] Chapters xiv. and xxix.
[106] "The Girvan Succession," Quart. Jour. Geol. Soc., xxxviii. (1882),
p. 537.
[107] The capelin (_Mallotus villosus_), which still lives in the
Atlantic.
[108] It was also seen the following year on the coast of Virginia, and
on that of Norway in both 1845 and 1846.
[109] He says that the alleged sea-serpent washed ashore at Stronsa
(Orkneys) in 1808 is proved by the bones (some of which are preserved)
to have been this animal.
[110] The formation, however, does not belong to the Carboniferous
system, but is shown by its fossils to be Jurassic in age.
[111] It is described and figured in later editions of the "Principles
of Geology," chap. xv. (eleventh edition).
[112] A species of _Gnathodon_.
[113] _Gnathodon cuneatus._
[114] A bayou is the name given to an old channel of the river. When the
latter is making a series of horseshoe curves, the stream often cuts
through the neck of land which separates its nearest parts. The water
then takes the shortest course, the entrances to the old channel are
silted up, and it becomes a horseshoe-shaped pool.
[115] T. Carlyle ("Letter on Secular Education").