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Bertram Coghill Alan Windle.

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scientific opinion on the topics now under consideration was largely due
to the constant stream of new discoveries which are daily being made
known to us. Here is an excellent example of this fact. At the date, 191 1,
when the book was published the statement just quoted might have well
been held to be correct, but the Piltdown skull, discussed in another
chapter, has robbed the Galley Hill example of its distinction, if scientific
opinion is correct, and may itself be thrown into the shade, comparatively
speaking, any day by some new discovery. However this may be, the age
and characters of the Galley Hill specimen are very noteworthy.



252 THE CHURCH AND SCIENCE

and elsewhere), and for the Magdalenian even colder con-
ditions. Probably the first -named stages should be assigned
to the dawn of the Wurmian — to the period of transition
from the preceding inter-glacial epoch, while the Magdalenian
belongs essentially to the succeeding glacial epoch."

Magdalenian man is traceable, either skeletally or by
means of his implements, all over the Continent of Europe :
he is to be met with in England, Belgium, Germany, Swit-
zerland, Austria, Russian Poland, etc. This does not
necessarily mean that he inhabited all this area at the same
period of time. What is quite probable is that as the
climate grew colder he migrated further south to middle
Europe, where it would seem that tundra conditions then
obtained.

The Recent Period

As the intense cold of the true glacial epoch passed away,
conditions similar to those which we now experience came
into existence and have since continued. It has already
been pointed out that we may be merely enjoying an interval
between two glacial periods. We may or may not be at
the maximum of the interval ; probably not, as it would
seem that the glaciers of the Alpine region are still in a
stage of regression. The speculation is not a very practical
one, but it may tend to engender a feeling of humility if
we reflect that there is really no apparent reason why con-
ditions may not occur under which the forces of nature will
once more assert themselves, the gigantic glaciers reappear
and wipe off the face of the earth every trace of the civilisa-
tions of Europe and North America.

So far we have been endeavouring to link with one
another the stories of the glacial period and of man's rela-
tion to it, and we have seen how many difficulties that task
presents and how diversely it has been accomplished by
different authorities. We now arrive at a period when
difficulties, at present apparently insuperable, have to
be confronted, and of these it will be necessary to take
stock.

The Magdalenian civilisation is a definite thing, clear-
cut and easily recognisable ; the same may be said of the



THE HIATUS 253

Neolithic civilisation which succeeded it. But the remark-
able thing is that the two seem to show little if any rela-
tionship to one another. This is an unexpected condition
of affairs, for there is no difference to account for it in the
character of the materials used : there is, however, a greater
break than that which occurred when metals came into
use. Moreover, there seems to have been also, in Europe,
or, at any rate, in Northern Europe, a complete contrast
in climate and in fauna. These points may be illustrated
by a table of contrasts prepared by W. B. Wright : —

Magdalenian Neolithic

Poorly developed Stone in- Highly developed Stone in-
dustry, dustry ; art of grinding

and polishing stone.

Remarkable skill in drawing Absolutely no pictorial art.
and etching.

Hunting and fishing the only Agriculture and the keeping

occupations. of domestic animals.

A cold fauna with reindeer The fauna of the present day.
and mammoth.

It is quite clear from a consideration of this table that we
have to do with two perfectly distinct and unrelated races
living under totally different conditions and amongst dis-
similar surroundings. It is inconceivable, for example,
that the wonderful art of the Magdalenian period should
have passed suddenly and completely out of existence,
leaving no trace of its former luxuriance, had there been
a continuity of race. The fact is that there seems to have
been no continuity and no link between these two civilisa-
tions — so much so that this time is commonly spoken of as
" The Hiatus." Of course it will be admitted that some-
where or another the gap must have been filled up, for no
one has ever suggested that there were two inhabitations
of the earth by races of men unrelated to one another.
But what at present seems to be undeniable is that in the
northern parts of Europe palaeolithic man did disappear
off the face of the earth, which was left without human
inhabitants for a lengthy period during which the physical



254 THE CHURCH AND SCIENCE

conditions as well as the character of the fauna were pro-
foundly altered.

" It is beyond question," says W. B. Wright, " that in
post-glacial times neither Ireland, Wales, nor the northern
half of Great Britain were occupied by man until the long
subsequent Neolithic invasion. Even the south of England
affords evidence of this general exodus, for here there is
a complete break both in stratigraphical relations and style
of workmanship between the implements of the two periods.
Between the Palaeolithic and Neolithic culture of Great
Britain there is a great gulf fixed, and no amount of re-
search has succeeded in finding any trace of a transition
between the two." 1

At the present moment — in spite of efforts to show some
trace of a transition at Larne in Ireland, at Cissbury in Eng-
land, and elsewhere — the statement just quoted must stand
as true. It is, however, more than probable that this diffi-
culty will be completely cleared up, possibly at a very
early date, by the numerous scientific excavations now
taking place in so many parts of Europe. Indeed there is
little doubt that Piette has discovered in the Grotto of
Mas d'Azil in France a series of zones which demon-
strate the transition stage with which we are now dealing.
From this grotto the zone of civilisation which we may look
upon as transitionary between the Palaeolithic and Neo-
lithic Ages has been named Asylian ; it is also called Tour-
assian ; and other transition periods have been denominated
Campignian, Tardenoisian, and Arisien. Over these matters
we cannot linger, but must content ourselves with noting
the fact that there is at present a hiatus in most parts of
Europe between the two great epochs of civilisation, which
hiatus we take, by actually observable evidence, to have
been bridged in certain spots in southern Europe. There
is, however, a difference of opinion as to when exactly this
Transition period was in existence. Hoernes, who, as we have
seen, pushes back all his races, assigns the Transition
(Asylian) period to the Fourth or Mecklenburgian glacial
epoch, which would bring the true Neoliths in at the com-
mencement of the present or fourth genial era. Geikie, on

1 " The Quaternary Ice Age," p. 78.



ASYLIAN PERIOD 255

the other hand, places the Asylian period in the present
genial epoch, thus throwing the Neolith nearer to our own
day. There is little doubt that the majority of prehistoric
archaeologists would agree with him.

Having thus endeavoured to sketch the history of the
Pleistocene epoch both geologically and anthropologically,
we must next turn our attention to the exceedingly vexed
questions of the age of the earth and of the age of man
upon it.



CHAPTER XXIV

THE AGE OF THE EARTH AND THE AGE OF
MAN ON IT

THERE is perhaps hardly any problem connected with
geological science which has been more widely
debated, or in relation to which more widely divergent
opinions have been arrived at, than that which is concerned
with the age of the earth ; and more especially with that
part of its existence, very small in comparison with the
whole, during which it has been inhabited by man.

No one need spend time in wondering why a question of
this kind should interest men of science : it is less obvious
to the general reader why the problem should offer such
almost insuperable difficulties. That it does so is proved
by the enormous discrepancies of the results arrived at — a
fact which will be obvious to anyone at all conversant with
the literature of the subject.

In order to regulate our own doings we must have some
measure of time — whether that measure be a watch or a
clock or whether we content ourselves with observations
of the sun or of heavenly bodies.

In like manner, in order to estimate the progress of time
in connection with the history of the earth, we must also
have some kind of measure — a " geological clock " : and
this is exactly what geologists have been looking for, so far
without any very conspicuous success.

A ship, which is lost unless it has an accurate timekeeper
on board, carries one or more chronometers supposed to be
absolutely faithful recorders of the passage of time. Even
the domestic clock is of little use to its owner unless it keeps
time ; the difficulty with most geological clocks is that we
cannot feel sure that they do keep time, nay more, we can

256



RIVER EROSION 257

feel almost sure with regard to them that they do not —
that is, that they have been " slower " or " faster " in the
past than they now are. One or two simple examples will
suffice to explain what is meant, and to illustrate the
difficulty there is in estimating even recent geological time.
Rivers carry down to the sea a certain amount of detritus
every year : this is measurable and has been carefully
measured in the case of some rivers, notably and most
carefully, for example, in the case of the Mississippi. This
detritus, being obtained by the wearing away of the bed
of the river, causes a slow deepening of the gorge in which
the river runs. It would seem to be an easy matter to esti-
mate the age of the river by a rule-of-three sum : a moment's
reflection, however, will show that unless we are quite
certain that the annual amount of detritus carried away
is a constant quantity, our calculations may be wholly
incorrect. But, it may be argued, it is easy to take an
average over a number of years. This might be possible
if we had some thousands of years' records on which to work
instead of fifty or sixty at the most. Even then it would
not give us an absolutely accurate estimate, for we should
still be uncertain whether the conditions in earlier ages had
not been wholly different from those of the time during which
observations had been made. In the immediate post-
glacial period, for example, when enormous glaciers were
in process of melting, immense volumes of water must have
poured through the watercourses with correspondingly
increased denudation and removal of detritus.
Again, take the rate of deposition of stalagmite. 1
In Kent's Cavern, near Torquay, there may be seen at
this day an inscription carved on a boss of rock which reads
" Robert Hedges of Ireland 1688," and is perhaps the record
of some fugitive of that troublous period. The existence
of this cave had been forgotten for many years until it was
rediscovered by a Catholic priest, Father McEnery, in the

1 It may perhaps be explained that stalagmite is the calcareous con-
cretion which often forms a floor, at times with fantastic upward projec-
tions, in limestone caverns, just as stalactite hangs stony festoons from
the roofs of the same. Both are due to the gradual deposit of carbonate of
lime dissolved in the water which slowly filters through the rock from the
surface soil.



258 THE CHURCH AND SCIENCE

middle of the last century. When the cave was scientifically
examined by the late Mr. Pengelly the inscription in question
was found to be covered by a thin but measurable coating
of stalagmite. The floor of the cave presented several feet
of stalagmite. If it had taken two hundred years to form
one-twentieth of an inch, or whatever it was, how many
years would it take to form four feet ? The question seems
easy of answer, but it is not ; for in another case, also in
England, ginger-beer bottles were actually found under a
foot deep of stalagmite. Here again the clock does not keep
time. The deposition of stalagmite depends upon the
amount of carbonate of lime in the percolating water ; that
to some extent depends upon the amount of carbon dioxide
in the water, and that again upon the nature of the soil it
passes through and the kind of vegetation which it carries.
Thus neither of these apparently promising clocks really
can be relied upon to keep time ; and in greater or lesser
extent this is also true of the many other " clocks " which
from time to time have been proposed to the scientific
world.

With this preliminary warning we may now turn our
attention to some of the most recent observations which
have been made upon this subject. 1 To begin with, we
have to decide from what point of view we are going to
commence to calculate the age of the earth. Whether it
began as a nebular gas or as a nebular collection of planetesi-
mals is of little consequence in this connection, for, so far
as it is possible to see, there is no means of deciding how long
ago either event may have taken place. Are we to calculate
from the time when the moon was cast out of the side of the
earth ? As to that there is ample margin for difference of
opinion, for Sir George Darwin estimated that this event
might have taken place at any time between 50,000,000 and
100,000,000 years ago. We may perhaps with benefit con-

1 For most of the facts, figures, and comments in the earlier part of
this chapter I am indebted to a paper by Professor Joly, f.r.s., which
appeared in the " Philosophical Magazine," September, 191 1, and was
republished, after revision, in the " Smithsonian Report " for 191 1,
pp. 271-93. The references in the text are to this publication. His book
" The Birth-Time of the World," which appeared after this chapter was
written, may also be commended to readers.



THE AGE OF THE OCEAN 259

sider the age of the ocean, at which there really is some
chance of arriving, and thus consider the age of the earth
from the time of the separation of dry land from sea. This
has been estimated by the calculation from solvent denuda-
tion. We must begin by noting that as the land was once
all dry and the water deposited on it from the clouds, the
first collections of fluid in the hollows — the future seas and
lakes — were all distilled water untainted with salt of any
kind. All the salts in the sea, then, must have accumulated
since that period and must have been derived from the earth
by the solvent denudation just mentioned. Our calculation
then must depend upon the percentage of sodium in sea-
water and be based on the average chemical composition of
river water and the probable annual discharge of the rivers
into the ocean. " The sodium which has reached the ocean
has originated in the conversion of igneous into sedimentary
rocks. It is easy to calculate from the composition of a
generalised igneous and a generalised sedimentary rock
and from the quantity of sodium in the ocean that the
denudation of about 84 million cubic miles of sediment
accounts for the sodium in the ocean. Such a quantity of
sedimentary rock would, if all was now on the land, cover
the present land area (55 million square miles) to a depth of
little over one mile." 1

No one denies that in calculating on this basis there are
numerous opportunities for mistake, nor that corrections
may have to be made in the future for points now foreseen
as well as quite probably for others unknown at the moment.
Subject to all these limitations — and it should ever be borne
in mind that no one is more insistent than the scientific man
as to the extremely tentative character of all such calcula-
tions — Professor Joly comes to the conclusion that " solvent
denudation, estimated in the only manner open to us,
assigns an age to the ocean which at its probable maximum
does not exceed 100,000,000 years," 1 and he adds: "It is
against probability to add 50 per cent to this value. We
can only double it by appealing purely and simply to the
imagination for effects of which we possess no indication,

1 J ol y> p- a82 -



26o



THE CHURCH AND SCIENCE



and the existence of which is at variance with what we
know." 1

Another method of estimating the age of the earth is
that by radioactivity, based upon the accumulation in
minerals of the inert products — helium and lead. The rate
of production of helium by a given amount of uranium may
be regarded as known with considerable accuracy, says
Joly ; and from this and from the mass of lead generated
annually per gram of uranium — assuming that lead is the
final product of decay in the uranium series — it is possible
to make an estimate of the age of the earth. Such an
estimate, in view of the inchoate state of our knowledge of
the whole subject of radioactivity, must be even more
tentative than that which is based on solvent denudation.
It is only mentioned here to show one more of the methods
of attack to which this problem has been subjected.

The age of the earth has this bearing on the question
with which we are especially concerned, in that the Pleisto-
cene Period can only bear a certain ratio to the whole,
indeed can only form a very small part of it ; so that the
longer or shorter period we allow for the whole will entail
a longer or shorter period for the part.

This being so we may now turn our attention to the
question of the maximum thickness of the strata deposited
in the various geological periods as estimated in the sub-
joined table. 2



Recent and Pleistocene ,
Pliocene ,
Miocene .
Oligocene ,
Eocene .


Feet.

4,000
. 13,000
. 14,000

, . 12,000
, . 20,000


Upper Cretaceous . ,
Lower Cretaceous . ,
Jurassic ,
Trias . . ,


, . 24,000

, . 20,000

, . 8,000
, . 17,000



63,000



69,000



1 Joly, p. 276.

2 Sollas, Presidential Address to the Geological Society of London
in 1909.



THE AGE OF THE EARTH



261



Permian .
Carboniferous
Devonian .

Silurian
Ordovician
Cambrian .

Keweenawan
Animikian
Huronian .

Archean .



Feet.
12,000

29,000

22,000

15,000

17,000
26,000

50,000
14,000
18,000



63,000

58,000

- 82,000
-335.000



Supposing that man was in existence during the entire
of the Pleistocene and Recent Period, it will be seen from
the above table how very small a part of the whole of
geological time that must needs be.

Professor Joly has been kind enough to plot out for me
Strutt's time (obtained by the radioactivity method)
against Sollas's data (as given in the table above) . By taking
square paper and joining the Oligocene point to the present,
which would be in such a diagram, some idea of the sub-
sequent periods should be got. On this calculation the
beginning of Pliocene time would be about 3 or 3-3 millions
of years ago, and the beginning of Pleistocene time about one
million years ago. In considering these figures the reader
must not fail to bear in mind that they are highly tentative
and based on data which may require extensive correction
and revision.

The matter of chief interest to us is the date of the advent
of man : or, in other words, we are more concerned to learn
what science has to say to-day on that subject than we are
to ascertain the latest views as to the actual age of the earth
itself. To this question of man and his date we may now
turn our attention.

In what follows readers can scarcely fail to be struck by
the amazing discrepancies which will be observed to exist



262 THE CHURCH AND SCIENCE

between the statements of different persons, all more or
less authorities on the subject with which they are dealing.
This at least clearly proves one thing — namely, that no real
certainty, scarcely even any probability, can attach to any
matter concerning which such extraordinary differences of
opinion exist. There is, however, another point to which
attention should be called and it is this : the writers to
whom we have been alluding may be divided accurately
enough into two classes, geologists and anthropologists — in
other words, into those who have made the earth and its
history their chief study and those who have devoted their
attention chiefly to man and his history. It may further
be remarked that, almost without exception, the more
extravagant demands for time will be found to be made by
anthropologists and not by geologists. The underlying
reason for this is that most anthropologists believe that the
body of man was evolved from that of some lower animal,
and moreover believe that the process of evolution occurred
by small variations taking place over a vast extent of time.
They, therefore, postulate that vast extent of time.

A little consideration will show that this is a very
unscientific way of going to work. If it were perfectly
certain — if it were as clear as any proposition of Euclid —
that the body of man had been evolved, and evolved by
the slow process alluded to, and if it were equally clear that
that process of evolution could not by any possibility have
taken place in less than so many years, then indeed it would
be allowable for the anthropologist to say to the geologist :
" You must find me so many years since the advent of
man, and if you cannot do so it is quite clear that your
methods are all wrong." In a later chapter these questions
will be considered, and it will be seen that the premises
for such a conclusion as that indicated above are in no kind
of way established.

Unless and until they are established, the question
remains, and, it may be added, seems likely always to
remain, a purely geological one, to be settled on purely
geological lines. It is, therefore, to the geologists that we
must turn, though it must be admitted that when we do
so we find ourselves confronted by hopeless discrepancies



THE RECENT PERIOD 263

even there. One instance of the difference of opinion
between geologists and anthropologists may here be cited
as an example of the classes of statements of which I have
been speaking. Mention has several times been made of the
Mousterian race and of their interments at Chapelle-aux-
Saintes. Professor Sollas, who is primarily a geologist
though also a high authority upon anthropology — in fact
one of the few men who can speak with real authority in
either house — places these interments at a distance of
25,000 years from the present day. Professor Keith, on the
other hand, who is an anthropologist of high standing but
who certainly would not claim to be a geological expert,
refuses to be satisfied with less than 350,000 years for the
period which has elapsed since the Mousterians placed this
particular dead man in his tomb. Nothing can better illus-
trate the points under discussion than this single example.

After these preliminary remarks we may devote a short
space to the consideration of the time theories of different
authorities and may commence by asking how long it is since
the Recent Period, in which we are now living, came into
existence. It is obvious that no fixed date can be given for
this. There was no particular morning on which Prehistoric
Man woke up to discover that the Mecklenburgian Glacial
Epoch had come to an end and the present genial epoch
had commenced. The passage from one to the other must
have been slow and gradual, and the dates, therefore, at best
can be but approximate.

The retreat of. the glaciers was slow and the extent of
Europe which they covered, even at their maximum,
limited. During the whole of the same glacial epoch men
and women were living and dying in other parts of the world,
even in other parts of Europe : what were these people and
what form of civilisation had they reached ? G. F. Wright, 1
who has been a student of glacial questions for forty years
and has published many important books and papers
on the subject, as we have already seen, makes his
view on the matter perfectly clear. His remarkable
statement may be repeated : " Large areas in Europe

1 "The Origin and Antiquity of Man," Oberlin, Ohio, U.S.A., 1912,
P- 195.



264 THE CHURCH AND SCIENCE

and North America which are now principal centres of
civilisation were buried under glacial ice thousands of feet
thick, while the civilisation of Babylonia was in its heyday "
—that is to say, some five to six thousand years ago.
Further, he continues : " The glib manner in which many,
not to say most, popular writers, as well as many observers



Online LibraryBertram Coghill Alan WindleThe church and science → online text (page 24 of 38)