A paper read at a meeting
of the Inverness Scientific Society and Field Club in 1908.
Having been honoured by a
request from the Secretary of the Inverness Scientific Society and Field
Club to write a paper, I rather reluctantly agreed, doubting my
capability of producing with ray pen anything sufficiently interesting
to make it worth listening to; and now that I have written on “ Peat," I
feel as one who is not an authority on the subject, but rather as one in
search of knowledge. Still, I hope that I may be the feeble means of
rousing someone else more capable than myself to take up and go fully
into the subject on which I write. I have often wondered why so very
much energy has been expended in writing and theorising on the
fundamental gneiss and the Torridon red, whereas no one seems to take
any notice of the thick black layer which usually covers both these
ancient rocks in this part of the country.
The American tourists
profess to be always interested in what they amusingly term the elegant
ruins of the old country." Now, though my peat is undoubtedly a ruin,
and a very old one, I fear I cannot exactly lay claim to its being very
elegant (being certainly more useful than ornamental), but I do think it
deserves to be classed among the most interesting natural phenomena of
our land. Not only is the actual peat itself interesting, but still more
interesting are the many objects found preserved in it. What excitement
there is when in Egypt or at Pompeii there are found grains of wheat in
a mummy, or well-preserved figs or walnuts are taken from under twenty
feet of volcanic ash ! Why should I, in my humble way, not be quite as
much elated when, from the bottom of one of my bogs, I take out handfuls
of hazel-nuts as perfect as the day they dropped off the trees; or,
still more wonderful, when I find the peat full of countless green
beetle wings, still glittering in their pristine metallic lustre, which
may have been buried in these black, airtight silos before Pompeii was
thought of?
To mark the manner in
which the climate of our earth has changed at different periods must
always be an interesting subject to the student of Nature, ancient or
modern. I cannot help thinking that, if the lower strata of some of our
very deepest peat-bogs were carefully examined, with the help of the
microscope, etc., the botanist and entomologist would derive information
which would give us some approximate idea of their age, and prove that a
somewhat different vegetation covered the earth when the peat began to
form, and that our country was then the abode of plants and insects (if
not of still higher forms of animal life) which are either very rare or
quite extinct with us now.
One bird has become
extinct even in my day—viz., the great auk; and what were indigenous
plants are becoming extinct from various causes, chiefly, I fancy,
climate. I know as a fact that, in my grandfather’s time, the woods of
this country were full of Epipactis ensifolia, a lovely white
orchidaceous plant, which is so rare now that I have only twice in my
lifetime seen one here, though I have found them in abundance in the
woods of the Pyrenees. Why has it died out ? Surely it is that the
climate has changed, and that it liked the hot summers of the last
century, when my grandfather regularly feasted at Gairloch on ripe
strawberries and cherries on the King’s birthday, the 4th of June;
whereas now, if he were alive, and still thought strawberries and
cherries necessary for the proper keeping of the festival, he would
require to shift the day to the 4th of July at least.
The green beetle wings in
the peat appear to be those of the rose-beetle, which is now rather a
rare insect with us, but which, judging by their debris in the peat,
must have swarmed at one time, like the locusts in Egypt in the days of
the plagues. Nowadays one comes across a few of them only in sunny
places facing the south, but these remains have been found in dark, dank
hollows, looking due north. Perhaps in the good old beetle days the
climate was so hot that they chose the shade in preference.
Now as to when the peat
began to form. It is evidently a post-glacial deposit, because, when out
deer-stalking, I notice beds of it lying on the top of ice-polished
slabs of gneiss. Geologists can give us no idea of the age of the rocks,
though they can tell us that some rocks are young in comparison to
others. I wonder whether they can make any guess at the date when the
snow and glaciers began to recede uphill from high-water mark? To look
at some of the ground in the Torridon and Gairloch deer-forests, one
would say that the final disappearance of the glaciers from some of
their high corries could not be such a very old story, as in some places
neither peat nor even plants have as yet managed to cover the slabs of
glaciated rock, which have still nothing on them but carried stones and
boulders of every shape and size, just as they were dropped on the slabs
when the ice departed. One cannot help wondering what the climate was
like when the ice began to disappear; if it was like the climate of
Switzerland in the present day—hot and dry in summer, and cold and dry
in winter—it would not encourage a growth of peat. If, on the contrary,
it was cool and wet, it would encourage a growth of the sphagnum mosses,
which I look on as the main creators of peat.
If the peat commenced to
grow immediately on the departure of the ice, it would be most likely
that the low grounds were then covered with Arctic plants, such as
Azalea procumbens, Betula nana, Saxifraga oppositifolia, which our
present climate has banished to the highest tops. Now, how interesting
it would be if, when microscopically examined, traces of the Azalea, for
instance, with its hard, twisted roots and stems, were found at the
bottom of the peat-bogs at the sea-level. Last year I found quantities
of yellow seeds at the base of a nine-foot cutting in the solid peat. So
I sent some of them, all washed and clean, to the late Professor Dickson
of Edinburgh. He showed them to my friend Mr. Lindsay, the curator of
the Edinburgh Royal Botanic Gardens, and said he had come to the
conclusion that some hoax had been played upon me, and that the seeds
were modern and not ancient. He was then just starting on a tour to
Norway, and on his return, sad to say, Professor Dickson died, and I
never heard any more of my seeds. But I determined not to give up my
interest in .them, so the other day I began looking for the seeds again,
and found them in quantities in the lowest part of the peat, where it
rested on the subsoil. I had other bogs examined, and there they were
also found among the compressed brown sphagnum below a great depth of
solid black peat. So I sent them, this time unwashed, to my friend Mr.
Lindsay, who in his reply said that at first he was in doubt as to
whether they were whin or broom seeds, but on comparing them with modern
seeds of both these shrubs, he had come to the conclusion that they were
whin seeds. Notwithstanding my having perfect faith in Mr. Lindsay (as a
botanist), I cannot take in the idea that these seeds are whin. Neither
the whin nor the broom is a native'plant here. One hundred years ago the
only broom plants in the district were a few sown round the garden of my
far-back predecessors in this place—the Mackenzies of Lochend of that
day— and the first whins that ever grew anywhere near here were produced
from seed sown by a certain Rev. Mr. Macrae, a minister on the Poolewe
glebe, and some sown also by a member of the Letterewe family at Udrigil.
It is certain it was not an indigenous plant here in modern
times,whatever it might have been in the beetle days, and there can be
no doubt that the shrubs or plants which produced these seeds lived
contemporaneously with the beetles.
We now find hazel, birch,
alder, and willow in the most perfect state at the bottom of the bogs,
with the silvery bark on the former kinds as perfect as when they were
growing, but no one has found the gnarled, twisted stems of the whin or
broom in any bog in this country. A most intelligent man, who has taken
a very lively interest in these seeds, has put forward the theory that
they may have been the seeds of the buck or bog bean which grew at one
time on the bottom of shallow lochs which have since filled up; but Mr.
Lindsay is not of this opinion.
There is, I think, an
impression abroad that peat is a very modern growth and is quickly
formed. I think this idea is quite erroneous. That it is very modern
compared with our rocks is certain, but, still, I hold to the belief
that our peat is a very old formation, though still growing slowly. Can
anyone tell when was the Bronze Age up here? We found a perfect bronze
spear-head in one of the peat-bogs, pretty near the surface, with a
deer's antler lying close to it; and, to show what a preservative peat
is, part of the wooden shaft of the spear was still to the fore when the
spear-head was found. Now, in the days of the primitive man who owned
this spear this peat-bog must have been very much what it is now,
otherwise the spear would not have been so near the surface.
There was also a very
valuable find of bronze antiquities in this neighbourhood a few years
ago. On going to examine the place, I found that the peat was not three
feet deep, showing that it had not grown much since the day when the
owner had buried his treasures, as it would not be likely that he would
have hidden them in a place having less than a couple of feet of peat at
least. Close to my house there is a bog in a hollow, enclosed all round
with a rim of rock, and on trying to drain it we found it impossible to
do so without cutting the rock. We probed the peat and found it fourteen
feet thick.
Usually the trees found
under the peat have their roots fixed in the subsoil and their stumps
are close to the bottom; but this is not always the case, for near the
surface of this bog we found several immense stumps, and, on attempting
to count the rings on one of the roots which we sawed off, we arrived at
the conclusion that the tree was about four hundred years old when it
ceased to live. Now, it is about four hundred years since my ancestors
came from Kintail and took possession of Gairloch by a coup de main, and
we know that at that time (and probably long before then) these shores
had a resident population. It is therefore unlikely that these trees
would have been allowed to remain standing so close to the seashore at
the head of Loch Ewe for very long after the place became inhabited.
Supposing these trees, then, to have been dead some five hundred years,
and that they were four hundred years old when destroyed, that takes us
nearly one thousand years back. Query, then how old is the lower layer
of peat in the bog which lies fourteen feet below the stumps?
I have heard of a bog at
Kenlochewe which was drained and improved, and in it were two distinct
sets of fir roots, one above the other, with a considerable layer of
peat between them. Nearly all the bog stumps in this country have marks
of fire on them and charcoal about them. Now, it would seem that in this
case two successive forests sprung up, grew to maturity, and were
destroyed, and that between each crop of fir there had been a sufficient
interregnum for the peat to form and to cover up and preserve each set
of roots. It would be what the lawyers would call “ a nice question ” as
to how many centuries the remains of the two forests and the layers of
peat represent.
One must not, however,
judge altogether of the age of peat by its depth. The best peat I have
ever seen for burning purposes was only one foot in depth below the top
sod, and had grown on blue clay, so that, as we cut the fuel, the lowest
end of each peat had the clay attached to it, and turned into red bricks
in the fire. These peats were nearly equal to coal, and were evidently
like the Irishman's pig, very little and very old, which is much more of
a merit in peat than in pigs.
I might go rambling on
with my peat stories—about peat at the bottom of lochs, and submarine
peat-bogs which I have seen at low spring-tides, which, I am ashamed to
say, I have never thoroughly examined, and which must, at least, have
the merit of being really very old; but instead of commencing anew I
will stop.
Since writing the above I
have been in the Lews, and I have seen there peat such as I never
imagined could be found anywhere in Great Britain. On the mainland of
Ross-shire it is uncommon to find peat six or eight feet deep, but
between Skigersta and North Tolsta the peat for miles is from sixteen to
twenty-six feet in depth.
Can any of my readers
help me to fathom some of the many mysteries that lie at the bottom of
our peat-bogs and lochs, which have always interested me so much? What
puzzles me perhaps most of all are the stems of birch and hazel which I
find six and eight feet below the surface, with the bark (especially of
the former) as smooth and glistening as if the trees had been cut only
the previous day; indeed, the bark of the bog birches is generally much
whiter than that of the more or less stunted modern birches of this west
coast, which is a purple-grey tint and quite different from the white
stems of the birches along the shores of Loch Ness—in fact, they are as
snowy white as the bark of those that grow to-day in Sweden and Russia!
I quite well know what
most people will say—viz., that the peat is a great preservative, and
that, as in the case of ensilage in a silo, decomposition has been
arrested by the exclusion of atmospheric air. But I would first of all
ask my readers how the birch-trees got into the bottom of these bogs. I
suppose they would answer that peat grows, and that it grew round these
birches and hazels, and thus preserved them, quite forgetting that peat
will not grow except where it is wet, and that neither birch nor hazel
will grow if the ground is at all wet. They also have, perhaps, very
little idea of the delicacy of the thin, white, outer skin of the birch
bark. Perhaps they imagine that if they cut down a birch or hazel tree,
and laid it on the top of a peat-bog, it would gradually sink down of
its own weight, or that the peat would grow up round it, and that thus
the silvery bark would be preserved; but I dare say most people have
also very little idea of the slowness of the growth of peat, and I may
mention that this white outer skin of birch bark is just like silver
paper, and would not remain attached to the stem more than a very few
months, and the birch branch or stem laid on the top of the bog would
turn into pulp and disappear long before the peat could grow over it to
preserve it.
It might be argued that,
supposing a birch-wood grew at the very foot of a mountain of, say,
2,000 to 3,000 feet high, and that the mountain was covered most of the
way up with a deep bed of peat, and that, owing to an earthquake or some
other inexplicable cause, the peat on the hillside began sliding down
like a black avalanche and overwhelmed the birch-wood, then one would
certainly quite understand the white bark on the-birches being
preserved. But, unfortunately, this theory is impossible, as deep peat
does not form on steep mountains in a sufficient quantity to cause a
landslide; and besides, where I came across the white-stemmed birches in
the bogs there are no hills high enough or near enough for peat or
anything else to have slipped down and covered these thousands of acres
of flat moor.
Then, as regards the
remains of forests at the bottom of lochs, I happen to own a great many
lochs and tarns, and when boating on them, on a calm day with a clear
sky, the tree-stumps can be seen side by side, just as they grew before
these lochs existed. Now, how were these lochs created to the ruin of
thousands of acres of forest? It would be most interesting to examine
some of the deeper lochs, with an electric light appliance, to see if
there are remains of forests in them as well as in the shallower ones. I
dare say some people will imagine that the roots have got washed into
the lochs in great floods; well, this might have happened so far as logs
or branches are concerned, but the stumps I refer to are all firmly
rooted in the bottom, each one just where the original grain of Pinus
sylvestris seed fell, germinated, and grew up.
THE END |