THE PART WHICH WORMS HAVE PLAYED IN THE BURIAL OF ANCIENT BUILDINGS.
The accumulation of rubbish on the sites of great cities independent of
the action of worms—The burial of a Roman villa at Abinger—The floors and
walls penetrated by worms—Subsidence of a modern pavement—The buried
pavement at Beaulieu Abbey—Roman villas at Chedworth and Brading—The
remains of the Roman town at Silchester—The nature of the débris by which
the remains are covered—The penetration of the tesselated floors and
walls by worms—Subsidence of the floors—Thickness of the mould—The old
Roman city of Wroxeter—Thickness of the mould—Depth of the foundations of
some of the Buildings—Conclusion.
ARCHÆOLOGISTS are probably not aware how much they owe to worms for the
preservation of many ancient objects. Coins, gold ornaments, stone
implements, &c., if dropped on the surface of the ground, will infallibly
be buried by the castings of worms in a few years, and will thus be
safely preserved, until the land at some future time is turned up. For
instance, many years ago a grass-field was ploughed on the northern side
of the Severn, not far from Shrewsbury; and a surprising number of iron
arrow-heads were found at the bottom of the furrows, which, as Mr.
Blakeway, a local antiquary, believed, were relics of the battle of
Shrewsbury in the year 1403, and no doubt had been originally left
strewed on the battle-field. In the present chapter I shall show that
not only implements, &c., are thus preserved, but that the floors and the
remains of many ancient buildings in England have been buried so
effectually, in large part through the action of worms, that they have
been discovered in recent times solely through various accidents. The
enormous beds of rubbish, several yards in thickness, which underlie many
cities, such as Rome, Paris, and London, the lower ones being of great
antiquity, are not here referred to, as they have not been in any way
acted on by worms. When we consider how much matter is daily brought
into a great city for building, fuel, clothing and food, and that in old
times when the roads were bad and the work of the scavenger was
neglected, a comparatively small amount was carried away, we may agree
with Élie de Beaumont, who, in discussing this subject, says, “pour une
voiture de matériaux qui en sort, on y en fait entrer cent.” {166a} Nor
should we overlook the effects of fires, the demolition of old buildings,
and the removal of rubbish to the nearest vacant space.
_Abinger_, _Surrey_.—Late in the autumn of 1876, the ground in an old
farm-yard at this place was dug to a depth of 2 to 2½ feet, and the
workmen found various ancient remains. This led Mr. T. H. Farrer of
Abinger Hall to have an adjoining ploughed field searched. On a trench
being dug, a layer of concrete, still partly covered with tesseræ (small
red tiles), and surrounded on two sides by broken-down walls, was soon
discovered. It is believed, {166b} that this room formed part of the
atrium or reception-room of a Roman villa. The walls of two or three
other small rooms were afterwards discovered. Many fragments of pottery,
other objects, and coins of several Roman emperors, dating from 133 to
361, and perhaps to 375 A.D., were likewise found. Also a half-penny of
George I., 1715. The presence of this latter coin seems an anomaly; but
no doubt it was dropped on the ground during the last century, and since
then there has been ample time for its burial under a considerable depth
of the castings of worms. From the different dates of the Roman coins we
may infer that the building was long inhabited. It was probably ruined
and deserted 1400 or 1500 years ago.
I was present during the commencement of the excavations (August 20,
1877) and Mr. Farrer had two deep trenches dug at opposite ends of the
atrium, so that I might examine the nature of the soil near the remains.
The field sloped from east to west at an angle of about 7°; and one of
the two trenches, shown in the accompanying section (Fig. 8) was at the
upper or eastern end. The diagram is on a scale of 1/20 of an inch to an
inch; but the trench, which was between 4 and 5 feet broad, and in parts
above 5 feet deep, has necessarily been reduced out of all proportion.
The fine mould over the floor of the atrium varied in thickness from 11
to 16 inches; and on the side of the trench in the section was a little
over 13 inches. After the mould had been removed, the floor appeared as
a whole moderately level; but it sloped in parts at an angle of 1°, and
in one place near the outside at as much as 8° 30′. The wall surrounding
the pavement was built of rough stones, and was 23 inches in thickness
where the trench was dug. Its broken summit was here 13 inches, but in
another part 15 inches, beneath the surface of the field, being covered
by this thickness of mould. In one spot, however, it rose to within 6
inches of the surface. On two sides of the room, where the junction of
the concrete floor with the bounding walls could be carefully examined,
there was no crack or separation. This trench afterwards proved to have
been dug within an adjoining room (11 ft. by 11 ft. 6 in. in size), the
existence of which was not even suspected whilst I was present.
[Picture: Fig. 8: Section through the foundations of a buried Roman
villa]
On the side of the trench farthest from the buried wall (W), the mould
varied from 9 to 14 inches in thickness; it rested on a mass (B) 23
inches thick of blackish earth, including many large stones. Beneath
this was a thin bed of very black mould (C), then a layer of earth full
of fragments of mortar (D), and then another thin bed (about 3 inches
thick) (E) of very black mould, which rested on the undisturbed subsoil
(F) of firm, yellowish, argillaceous sand. The 23-inch bed (B) was
probably made ground, as this would have brought up the floor of the room
to a level with that of the atrium. The two thin beds of black mould at
the bottom of the trench evidently marked two former land-surfaces.
Outside the walls of the northern room, many bones, ashes, oyster-shells,
broken pottery and an entire pot were subsequently found at a depth of 16
inches beneath the surface.
The second trench was dug on the western or lower side of the villa: the
mould was here only 6½ inches in thickness, and it rested on a mass of
fine earth full of stones, broken tiles and fragments of mortar, 34
inches in thickness, beneath which was the undisturbed sand. Most of
this earth had probably been washed down from the upper part of the
field, and the fragments of stones, tiles, &c., must have come from the
immediately adjoining ruins.
It appears at first sight a surprising fact that this field of light
sandy soil should have been cultivated and ploughed during many years,
and that not a vestige of these buildings should have been discovered.
No one even suspected that the remains of a Roman villa lay hidden close
beneath the surface. But the fact is less surprising when it is known
that the field, as the bailiff believed, had never been ploughed to a
greater depth than 4 inches. It is certain that when the land was first
ploughed, the pavement and the surrounding broken walls must have been
covered by at least 4 inches of soil, for otherwise the rotten concrete
floor would have been scored by the ploughshare, the tesseræ torn up, and
the tops of the old walls knocked down.
When the concrete and tesseræ were first cleared over a space of 14 by 9
ft., the floor which was coated with trodden-down earth exhibited no
signs of having been penetrated by worms; and although the overlying fine
mould closely resembled that which in many places has certainly been
accumulated by worms, yet it seemed hardly possible that this mould could
have been brought up by worms from beneath the apparently sound floor.
It seemed also extremely improbable that the thick walls, surrounding the
room and still united to the concrete, had been undermined by worms, and
had thus been caused to sink, being afterwards covered up by their
castings. I therefore at first concluded that all the fine mould above
the ruins had been washed down from the upper parts of the field; but we
shall soon see that this conclusion was certainly erroneous, though much
fine earth is known to be washed down from the upper part of the field in
its present ploughed state during heavy rains.
Although the concrete floor did not at first appear to have been anywhere
penetrated by worms, yet by the next morning little cakes of the
trodden-down earth had been lifted up by worms over the mouths of seven
burrows, which passed through the softer parts of the naked concrete, or
between the interstices of the tesseræ. On the third morning twenty-five
burrows were counted; and by suddenly lifting up the little cakes of
earth, four worms were seen in the act of quickly retreating. Two
castings were thrown up during the third night on the floor, and these
were of large size. The season was not favourable for the full activity
of worms, and the weather had lately been hot and dry, so that most of
the worms now lived at a considerable depth. In digging the two trenches
many open burrows and some worms were encountered at between 30 and 40
inches beneath the surface; but at a greater depth they became rare. One
worm, however, was cut through at 48½, and another at 51½ inches beneath
the surface. A fresh humus-lined burrow was also met with at a depth of
57 and another at 65½ inches. At greater depths than this, neither
burrows nor worms were seen.
As I wished to learn how many worms lived beneath the floor of the
atrium—a space of about 14 by 9 feet—Mr. Farrer was so kind as to make
observations for me, during the next seven weeks, by which time the worms
in the surrounding country were in full activity, and were working near
the surface. It is very improbable that worms should have migrated from
the adjoining field into the small space of the atrium, after the
superficial mould in which they prefer to live, had been removed. We may
therefore conclude that the burrows and the castings which were seen here
during the ensuing seven weeks were the work of the former inhabitants of
the space. I will now give a few extracts from Mr. Farrer’s notes.
Aug. 26th, 1877; that is, five days after the floor had been cleared. On
the previous night there had been some heavy rain, which washed the
surface clean, and now the mouths of forty burrows were counted. Parts
of the concrete were seen to be solid, and had never been penetrated by
worms, and here the rain-water lodged.
Sept. 5th.—Tracks of worms, made during the previous night, could be seen
on the surface of the floor, and five or six vermiform castings had been
thrown up. These were defaced.
Sept. 12th.—During the last six days, the worms have not been active,
though many castings have been ejected in the neighbouring fields; but on
this day the earth was a little raised over the mouths of the burrows, or
castings were ejected, at ten fresh points. These were defaced. It
should be understood that when a fresh burrow is spoken of, this
generally means only that an old burrow has been re-opened. Mr. Farrer
was repeatedly struck with the pertinacity with which the worms re-opened
their old burrows, even when no earth was ejected from them. I have
often observed the same fact, and generally the mouths of the burrows are
protected by an accumulation of pebbles, sticks or leaves. Mr. Farrer
likewise observed that the worms living beneath the floor of the atrium
often collected coarse grains of sand, and such little stones as they
could find, round the mouths of their burrows.
Sept. 13th; soft wet weather. The mouths of the burrows were re-opened,
or castings were ejected, at 31 points; these were all defaced.
Sept. 14th; 34 fresh holes or castings; all defaced.
Sept. 15th; 44 fresh holes, only 5 castings; all defaced.
Sept. 18th; 43 fresh holes, 8 castings; all defaced.
The number of castings on the surrounding fields was now very large.
Sept. 19th; 40 holes, 8 castings; all defaced.
Sept. 22nd; 43 holes, only a few fresh castings; all defaced.
Sept. 23rd; 44 holes, 8 castings.
Sept. 25th; 50 holes, no record of the number of castings.
Oct. 13th; 61 holes, no record of the number of castings.
After an interval of three years, Mr. Farrer, at my request, again looked
at the concrete floor, and found the worms still at work.
Knowing what great muscular power worms possess, and seeing how soft the
concrete was in many parts, I was not surprised at its having been
penetrated by their burrows; but it is a more surprising fact that the
mortar between the rough stones of the thick walls, surrounding the
rooms, was found by Mr. Farrer to have been penetrated by worms. On
August 26th, that is, five days after the ruins had been exposed, he
observed four open burrows on the broken summit of the eastern wall (W in
Fig. 8); and, on September 15th, other burrows similarly situated were
seen. It should also be noted that in the perpendicular side of the
trench (which was much deeper than is represented in Fig. 8) three recent
burrows were seen, which ran obliquely far down beneath the base of the
old wall.
We thus see that many worms lived beneath the floor and the walls of the
atrium at the time when the excavations were made; and that they
afterwards almost daily brought up earth to the surface from a
considerable depth. There is not the slightest reason to doubt that
worms have acted in this manner ever since the period when the concrete
was sufficiently decayed to allow them to penetrate it; and even before
that period they would have lived beneath the floor, as soon as it became
pervious to rain, so that the soil beneath was kept damp. The floor and
the walls must therefore have been continually undermined; and fine earth
must have been heaped on them during many centuries, perhaps for a
thousand years. If the burrows beneath the floor and walls, which it is
probable were formerly as numerous as they now are, had not collapsed in
the course of time in the manner formerly explained, the underlying earth
would have been riddled with passages like a sponge; and as this was not
the case, we may feel sure that they have collapsed. The inevitable
result of such collapsing during successive centuries, will have been the
slow subsidence of the floor and of the walls, and their burial beneath
the accumulated worm-castings. The subsidence of a floor, whilst it
still remains nearly horizontal, may at first appear improbable; but the
case presents no more real difficulty than that of loose objects strewed
on the surface of a field, which, as we have seen, become buried several
inches beneath the surface in the course of a few years, though still
forming a horizontal layer parallel to the surface. The burial of the
paved and level path on my lawn, which took place under my own
observation, is an analogous case. Even those parts of the concrete
floor which the worms could not penetrate would almost certainly have
been undermined, and would have sunk, like the great stones at Leith Hill
Place and Stonehenge, for the soil would have been damp beneath them.
But the rate of sinking of the different parts would not have been quite
equal, and the floor was not quite level. The foundations of the
boundary walls lie, as shown in the section, at a very small depth
beneath the surface; they would therefore have tended to subside at
nearly the same rate as the floor. But this would not have occurred if
the foundations had been deep, as in the case of some other Roman ruins
presently to be described.
Finally, we may infer that a large part of the fine vegetable mould,
which covered the floor and the broken-down walls of this villa, in some
places to a thickness of 16 inches, was brought up from below by worms.
From facts hereafter to be given there can be no doubt that some of the
finest earth thus brought up will have been washed down the sloping
surface of the field during every heavy shower of rain. If this had not
occurred a greater amount of mould would have accumulated over the ruins
than that now present. But beside the castings of worms and some earth
brought up by insects, and some accumulation of dust, much fine earth
will have been washed over the ruins from the upper parts of the field,
since it has been under cultivation; and from over the ruins to the lower
parts of the slope; the present thickness of the mould being the
resultant of these several agencies.
* * * * *
I may here append a modern instance of the sinking of a pavement,
communicated to me in 1871 by Mr. Ramsay, Director of the Geological
Survey of England. A passage without a roof, 7 feet in length by 3 feet
2 inches in width, led from his house into the garden, and was paved with
slabs of Portland stone. Several of these slabs were 16 inches square,
others larger, and some a little smaller. This pavement had subsided
about 3 inches along the middle of the passage, and two inches on each
side, as could be seen by the lines of cement by which the slabs had been
originally joined to the walls. The pavement had thus become slightly
concave along the middle; but there was no subsidence at the end close to
the house. Mr. Ramsay could not account for this sinking, until he
observed that castings of black mould were frequently ejected along the
lines of junction between the slabs; and these castings were regularly
swept away. The several lines of junction, including those with the
lateral walls, were altogether 39 feet 2 inches in length. The pavement
did not present the appearance of ever having been renewed, and the house
was believed to have been built about eighty-seven years ago.
Considering all these circumstances, Mr. Ramsay does not doubt that the
earth brought up by the worms since the pavement was first laid down, or
rather since the decay of the mortar allowed the worms to burrow through
it, and therefore within a much shorter time than the eighty-seven years,
has sufficed to cause the sinking of the pavement to the above amount,
except close to the house, where the ground beneath would have been kept
nearly dry.
Beaulieu Abbey, Hampshire.—This abbey was destroyed by Henry VIII., and
there now remains only a portion of the southern aisle-wall. It is
believed that the king had most of the stones carried away for building a
castle; and it is certain that they have been removed. The positions of
the nave and transepts were ascertained not long ago by the foundations
having been found; and the place is now marked by stones let into the
ground. Where the abbey formerly stood, there now extends a smooth
grass-covered surface, which resembles in all respects the rest of the
field. The guardian, a very old man, said the surface had never been
levelled in his time. In the year 1853, the Duke of Buccleuch had three
holes dug in the turf within a few yards of one another, at the western
end of the nave; and the old tesselated pavement of the abbey was thus
discovered. These holes were afterwards surrounded by brickwork, and
protected by trap-doors, so that the pavement might be readily inspected
and preserved. When my son William examined the place on January 5,
1872, he found that the pavement in the three holes lay at depths of 6¾,
10 and 11½ inches beneath the surrounding turf-covered surface. The old
guardian asserted that he was often forced to remove worm-castings from
the pavement; and that he had done so about six months before. My son
collected all from one of the holes, the area of which was 5.32 square
feet, and they weighed 7.97 ounces. Assuming that this amount had
accumulated in six months, the accumulation during a year on a square
yard would be 1.68 pounds, which, though a large amount, is very small
compared with what, as we have seen, is often ejected on fields and
commons. When I visited the abbey on June 22, 1877, the old man said
that he had cleared out the holes about a month before, but a good many
castings had since been ejected. I suspect that he imagined that he
swept the pavements oftener than he really did, for the conditions were
in several respects very unfavourable for the accumulation of even a
moderate amount of castings. The tiles are rather large, viz., about 5½
inches square, and the mortar between them was in most places sound, so
that the worms were able to bring up earth from below only at certain
points. The tiles rested on a bed of concrete, and the castings in
consequence consisted in large part (viz., in the proportion of 19 to 33)
of particles of mortar, grains of sand, little fragments of rock, bricks
or tile; and such substances could hardly be agreeable, and certainly not
nutritious, to worms.
My son dug holes in several places within the former walls of the abbey,
at a distance of several yards from the above described bricked squares.
He did not find any tiles, though these are known to occur in some other
parts, but he came in one spot to concrete on which tiles had once
rested. The fine mould beneath the turf on the sides of the several
holes, varied in thickness from only 2 to 2¾ inches, and this rested on a
layer from 8¾ to above 11 inches in thickness, consisting of fragments of
mortar and stone-rubbish with the interstices compactly filled up with
black mould. In the surrounding field, at a distance of 20 yards from
the abbey, the fine vegetable mould was 11 inches thick.
We may conclude from these facts that when the abbey was destroyed and
the stones removed, a layer of rubbish was left over the whole surface,
and that as soon as the worms were able to penetrate the decayed concrete
and the joints between the tiles, they slowly filled up the interstices
in the overlying rubbish with their castings, which were afterwards
accumulated to a thickness of nearly three inches over the whole surface.
If we add to this latter amount the mould between the fragments of
stones, some five or six inches of mould must have been brought up from
beneath the concrete or tiles. The concrete or tiles will consequently
have subsided to nearly this amount. The bases of the columns of the
aisles are now buried beneath mould and turf. It is not probable that
they can have been undermined by worms, for their foundations would no
doubt have been laid at a considerable depth. If they have not subsided,
the stones of which the columns were constructed must have been removed
from beneath the former level of the floor.
_Chedworth_, _Gloucestershire_.—The remains of a large Roman villa were
discovered here in 1866, on ground which had been covered with wood from
time immemorial. No suspicion seems ever to have been entertained that
ancient buildings lay buried here, until a gamekeeper, in digging for
rabbits, encountered some remains. {183} But subsequently the tops of
some stone walls were detected in parts of the wood, projecting a little
above the surface of the ground. Most of the coins found here belonged
to Constans (who died 350 A.D.) and the Constantine family. My sons
Francis and Horace visited the place in November 1877, for the sake of
ascertaining what part worms may have played in the burial of these
extensive remains. But the circumstances were not favourable for this
object, as the ruins are surrounded on three sides by rather steep banks,
down which earth is washed during rainy weather. Moreover most of the
old rooms have been covered with roofs, for the protection of the elegant
tesselated pavements.
A few facts may, however, be given on the thickness of the soil over
these ruins. Close outside the northern rooms there is a broken wall,
the summit of which was covered by 5 inches of black mould; and in a hole
dug on the outer side of this wall, where the ground had never before
been disturbed, black mould, full of stones, 26 inches in thickness, was
found, resting on the undisturbed sub-soil of yellow clay. At a depth of
22 inches from the surface a pig’s jaw and a fragment of a tile were
found. When the excavations were first made, some large trees grew over
the ruins; and the stump of one has been left directly over a party-wall
near the bath-room, for the sake of showing the thickness of the
superincumbent soil, which was here 38 inches. In one small room, which,
after being cleared out, had not been roofed over, my sons observed the
hole of a worm passing through the rotten concrete, and a living worm was
found within the concrete. In another open room worm-castings were seen
on the floor, over which some earth had by this means been deposited, and
here grass now grew.
_Brading_, _Isle of Wight_.—A fine Roman villa was discovered here in
1880; and by the end of October no less than 18 chambers had been more or
less cleared. A coin dated 337 A.D. was found. My son William visited
the place before the excavations were completed; and he informs me that
most of the floors were at first covered with much rubbish and fallen
stones, having their interstices completely filled up with mould,
abounding, as the workmen said, with worms, above which there was mould
without any stones. The whole mass was in most places from 3 to above 4
ft. in thickness. In one very large room the overlying earth was only 2
ft. 6 in. thick; and after this had been removed, so many castings were
thrown up between the tiles that the surface had to be almost daily
swept. Most of the floors were fairly level. The tops of the
broken-down walls were covered in some places by only 4 or 5 inches of
soil, so that they were occasionally struck by the plough, but in other
places they were covered by from 13 to 18 inches of soil. It is not
probable that these walls could have been undermined by worms and
subsided, as they rested on a foundation of very hard red sand, into
which worms could hardly burrow. The mortar, however, between the stones
of the walls of a hypocaust was found by my son to have been penetrated
by many worm-burrows. The remains of this villa stand on land which
slopes at an angle of about 3°; and the land appears to have been long
cultivated. Therefore no doubt a considerable quantity of fine earth has
been washed down from the upper parts of the field, and has largely aided
in the burial of these remains.
_Silchester_, _Hampshire_.—The ruins of this small Roman town have been
better preserved than any other remains of the kind in England. A broken
wall, in most parts from 15 to 18 feet in height and about 1½ mile in
compass, now surrounds a space of about 100 acres of cultivated land, on
which a farm-house and a church stand. {187} Formerly, when the weather
was dry, the lines of the buried walls could be traced by the appearance
of the crops; and recently very extensive excavations have been
undertaken by the Duke of Wellington, under the superintendence of the
late Rev. J. G. Joyce, by which means many large buildings have been
discovered. Mr. Joyce made careful coloured sections, and measured the
thickness of each bed of rubbish, whilst the excavations were in
progress; and he has had the kindness to send me copies of several of
them. When my sons Francis and Horace visited these ruins, he
accompanied them, and added his notes to theirs.
Mr. Joyce estimates that the town was inhabited by the Romans for about
three centuries; and no doubt much matter must have accumulated within
the walls during this long period. It appears to have been destroyed by
fire, and most of the stones used in the buildings have since been
carried away. These circumstances are unfavourable for ascertaining the
part which worms have played in the burial of the ruins; but as careful
sections of the rubbish overlying an ancient town have seldom or never
before been made in England, I will give copies of the most
characteristic portions of some of those made by Mr. Joyce. They are of
too great length to be here introduced entire.
An east and west section, 30 ft. in length, was made across a room in the
Basilica, now called the Hall of the Merchants (Fig. 9). The hard
concrete floor, still covered here and there with tesseræ, was found at 3
ft. beneath the surface of the field, which was here level. On the floor
there were two large piles of charred wood, one alone of which is shown
in the part of the section here given. This pile was covered by a thin
white layer of decayed stucco or plaster, above which was a mass,
presenting a singularly disturbed appearance, of broken tiles, mortar,
rubbish and fine gravel, together 27 inches in thickness. Mr. Joyce
believes that the gravel was used in making the mortar or concrete, which
has since decayed, some of the lime probably having been dissolved. The
disturbed state of the rubbish may have been due to its having been
searched for building stones. This bed was capped by fine vegetable
mould, 9 inches in thickness. From these facts we may conclude that the
Hall was burnt down, and that much rubbish fell on the floor, through and
from which the worms slowly brought up the mould, now forming the surface
of the level field.
[Picture: Fig. 7: Section through one of the fallen Druidical stones at
Stonehenge. Fig. 9: Section within a room in the Basilica at Silchester]
A section across the middle of another hall in the Basilica, 32 feet 6
inches in length, called the Ærarium, is shown in Fig. 10. It appears
that we have here evidence of two fires, separated by an interval of
time, during which the 6 inches of “mortar and concrete with broken
tiles” was accumulated. Beneath one of the layers of charred wood, a
valuable relic, a bronze eagle, was found; and this shows that the
soldiers must have deserted the place in a panic. Owing to the death of
Mr. Joyce, I have not been able to ascertain beneath which of the two
layers the eagle was found. The bed of rubble overlying the undisturbed
gravel originally formed, as I suppose, the floor, for it stands on a
level with that of a corridor, outside the walls of the Hall; but the
corridor is not shown in the section as here given. The vegetable mould
was 16 inches thick in the thickest part; and the depth from the surface
of the field, clothed with herbage, to the undisturbed gravel, was 40
inches.
[Picture: Fig. 10: Section within a hall in the Basilica of Silchester]
The section shown in Fig. 11 represents an excavation made in the middle
of the town, and is here introduced because the bed of “rich mould”
attained, according to Mr. Joyce, the unusual thickness of 20 inches.
Gravel lay at the depth of 48 inches from the surface; but it was not
ascertained whether this was in its natural state, or had been brought
here and had been rammed down, as occurs in some other places.
[Picture: Fig. 11: Section in a block of buildings in the middle of the
town of Silchester]
The section shown in Fig. 12 was taken in the centre of the Basilica, and
though it was 5 feet in depth, the natural sub-soil was not reached. The
bed marked “concrete” was probably at one time a floor; and the beds
beneath seem to be the remnants of more ancient buildings. The vegetable
mould was here only 9 inches thick. In some other sections, not copied,
we likewise have evidence of buildings having been erected over the ruins
of older ones. In one case there was a layer of yellow clay of very
unequal thickness between two beds of débris, the lower one of which
rested on a floor with tesseræ. The ancient broken walls appear to have
been sometimes roughly cut down to a uniform level, so as to serve as the
foundations for a temporary building; and Mr. Joyce suspects that some of
these buildings were wattled sheds, plastered with clay, which would
account for the above-mentioned layer of clay.
[Picture: Fig. 12: Section in the centre of the Basilica at Silchester]
Turning now to the points which more immediately concern us.
Worm-castings were observed on the floors of several of the rooms, in one
of which the tesselation was unusually perfect. The tesseræ here
consisted of little cubes of hard sandstone of about 1 inch, several of
which were loose or projected slightly above the general level. One or
occasionally two open worm-burrows were found beneath all the loose
tesseræ. Worms have also penetrated the old walls of these ruins. A
wall, which had just been exposed to view during the excavations then in
progress, was examined; it was built of large flints, and was 18 inches
in thickness. It appeared sound, but when the soil was removed from
beneath, the mortar in the lower part was found to be so much decayed
that the flints fell apart from their own weight. Here, in the middle of
the wall, at a depth of 29 inches beneath the old floor and of 49½ inches
beneath the surface of the field, a living worm was found, and the mortar
was penetrated by several burrows.
A second wall was exposed to view for the first time, and an open burrow
was seen on its broken summit. By separating the flints this burrow was
traced far down in the interior of the wall; but as some of the flints
cohered firmly, the whole mass was disturbed in pulling down the wall,
and the burrow could not be traced to the bottom. The foundations of a
third wall, which appeared quite sound, lay at a depth of 4 feet beneath
one of the floors, and of course at a considerably greater depth beneath
the level of the ground. A large flint was wrenched out of the wall at
about a foot from the base, and this required much force, as the mortar
was sound; but behind the flint in the middle of the wall, the mortar was
friable, and here there were worm-burrows. Mr. Joyce and my sons were
surprised at the blackness of the mortar in this and in several other
cases, and at the presence of mould in the interior of the walls. Some
may have been placed there by the old builders instead of mortar; but we
should remember that worms line their burrows with black humus. Moreover
open spaces would almost certainly have been occasionally left between
the large irregular flints; and these spaces, we may feel sure, would be
filled up by the worms with their castings, as soon as they were able to
penetrate the wall. Rain-water, oozing down the burrows would also carry
fine dark-coloured particles into every crevice. Mr. Joyce was at first
very sceptical about the amount of work which I attributed to worms; but
he ends his notes with reference to the last-mentioned wall by saying,
“This case caused me more surprise and brought more conviction to me than
any other. I should have said, and did say, that it was quite impossible
such a wall could have been penetrated by earth-worms.”
In almost all the rooms the pavement has sunk considerably, especially
towards the middle; and this is shown in the three following sections.
The measurements were made by stretching a string tightly and
horizontally over the floor. The section, Fig. 13, was taken from north
to south across a room, 18 feet 4 inches in length, with a nearly perfect
pavement, next to the “Red Wooden Hut.” In the northern half, the
subsidence amounted to 5¾ inches beneath the level of the floor as it now
stands close to the walls; and it was greater in the northern than in the
southern half; but, according to Mr. Joyce, the entire pavement has
obviously subsided. In several places, the tesseræ appeared as if drawn
a little away from the walls; whilst in other places they were still in
close contact with them.
[Picture: Fig. 14: A north and south section through the subsided floor
of a corridor]
In Fig. 14, we see a section across the paved floor of the southern
corridor or ambulatory of a quadrangle, in an excavation made near “The
Spring.” The floor is 7 feet 9 inches wide, and the broken-down walls
now project only ¾ of an inch above its level. The field, which was in
pasture, here sloped from north to south, at an angle of 30°, 40′. The
nature of the ground at some little distance on each side of the corridor
is shown in the section. It consisted of earth full of stones and other
débris, capped with dark vegetable mould which was thicker on the lower
or southern than on the northern side. The pavement was nearly level
along lines parallel to the side-walls, but had sunk in the middle as
much as 7¾ inches.
A small room at no great distance from that represented in Fig. 13, had
been enlarged by the Roman occupier on the southern side, by an addition
of 5 feet 4 inches in breadth. For this purpose the southern wall of the
house had been pulled down, but the foundations of the old wall had been
left buried at a little depth beneath the pavement of the enlarged room.
Mr. Joyce believes that this buried wall must have been built before the
reign of Claudius II., who died 270 A.D. We see in the accompanying
section, Fig. 15, that the tesselated pavement has subsided to a less
degree over the buried wall than elsewhere; so that a slight convexity or
protuberance here stretched in a straight line across the room. This led
to a hole being dug, and the buried wall was thus discovered.
[Picture: Fig. 15: Section through the subsided floor]
We see in these three sections, and in several others not given, that the
old pavements have sunk or sagged considerably. Mr. Joyce formerly
attributed this sinking solely to the slow settling of the ground. That
there has been some settling is highly probable, and it may be seen in
Fig. 15 that the pavement for a width of 5 feet over the southern
enlargement of the room, which must have been built on fresh ground, has
sunk a little more than on the old northern side. But this sinking may
possibly have had no connection with the enlargement of the room; for in
Fig. 13 one half of the pavement has subsided more than the other half
without any assignable cause. In a bricked passage to Mr. Joyce’s own
house, laid down only about six years ago, the same kind of sinking has
occurred as in the ancient buildings. Nevertheless it does not appear
probable that the whole amount of sinking can be thus accounted for. The
Roman builders excavated the ground to an unusual depth for the
foundations of their walls, which were thick and solid; it is therefore
hardly credible that they should have been careless about the solidity of
the bed on which their tesselated and often ornamented pavements were
laid. The sinking must, as it appears to me, be attributed in chief part
to the pavement having been undermined by worms, which we know are still
at work. Even Mr. Joyce at last admitted that this could not have failed
to have produced a considerable effect. Thus also the large quantity of
fine mould overlying the pavements can be accounted for, the presence of
which would otherwise be inexplicable. My sons noticed that in one room
in which the pavement had sagged very little, there was an unusually
small amount of overlying mould.
As the foundations of the walls generally lie at a considerable depth,
they will either have not subsided at all through the undermining action
of worms, or they will have subsided much less than the floor. This
latter result would follow from worms not often working deep down beneath
the foundations; but more especially from the walls not yielding when
penetrated by worms, whereas the successively formed burrows in a mass of
earth, equal to one of the walls in depth and thickness, would have
collapsed many times since the desertion of the ruins, and would
consequently have shrunk or subsided. As the walls cannot have sunk much
or at all, the immediately adjoining pavement from adhering to them will
have been prevented from subsiding; and thus the present curvature of the
pavement is intelligible.
The circumstance which has surprised me most with respect to Silchester
is that during the many centuries which have elapsed since the old
buildings were deserted, the vegetable mould has not accumulated over
them to a greater thickness than that here observed. In most places it
is only about 9 inches in thickness, but in some places 12 or even more
inches. In Fig. 11, it is given as 20 inches, but this section was drawn
by Mr. Joyce before his attention was particularly called to this
subject. The land enclosed within the old walls is described as sloping
slightly to the south; but there are parts which, according to Mr. Joyce,
are nearly level, and it appears that the mould is here generally thicker
than elsewhere. The surface slopes in other parts from west to east, and
Mr. Joyce describes one floor as covered at the western end by rubbish
and mould to a thickness of 28½ inches, and at the eastern end by a
thickness of only 11½ inches. A very slight slope suffices to cause
recent castings to flow downwards during heavy rain, and thus much earth
will ultimately reach the neighbouring rills and streams and be carried
away. By this means, the absence of very thick beds of mould over these
ancient ruins may, as I believe, be explained. Moreover most of the land
here has long been ploughed, and this would greatly aid the washing away
of the finer earth during rainy weather.
The nature of the beds immediately beneath the vegetable mould in some of
the sections is rather perplexing. We see, for instance, in the section
of an excavation in a grass meadow (Fig. 14), which sloped from north to
south at an angle of 3° 40′, that the mould on the upper side is only six
inches and on the lower side nine inches in thickness. But this mould
lies on a mass (25½ inches in thickness on the upper side) “of dark brown
mould,” as described by Mr. Joyce, “thickly interspersed with small
pebbles and bits of tiles, which present a corroded or worn appearance.”
The state of this dark-coloured earth is like that of a field which has
long been ploughed, for the earth thus becomes intermingled with stones
and fragments of all kinds which have been much exposed to the weather.
If during the course of many centuries this grass meadow and the other
now cultivated fields have been at times ploughed, and at other times
left as pasture, the nature of the ground in the above section is
rendered intelligible. For worms will continually have brought up fine
earth from below, which will have been stirred up by the plough whenever
the land was cultivated. But after a time a greater thickness of fine
earth will thus have been accumulated than could be reached by the
plough; and a bed like the 25½-inch mass, in Fig. 14, will have been
formed beneath the superficial mould, which latter will have been brought
to the surface within more recent times, and have been well sifted by the
worms.
_Wroxeter_, _Shropshire_.—The old Roman city of Uriconium was founded in
the early part of the second century, if not before this date; and it was
destroyed, according to Mr. Wright, probably between the middle of the
fourth and fifth century. The inhabitants were massacred, and skeletons
of women were found in the hypocausts. Before the year 1859, the sole
remnant of the city above ground, was a portion of a massive wall about
20 ft. in height. The surrounding land undulates slightly, and has long
been under cultivation. It had been noticed that the corn-crops ripened
prematurely in certain narrow lines, and that the snow remained unmelted
in certain places longer than in others. These appearances led, as I was
informed, to extensive excavations being undertaken. The foundations of
many large buildings and several streets have thus been exposed to view.
The space enclosed within the old walls is an irregular oval, about 1¾
mile in length. Many of the stones or bricks used in the buildings must
have been carried away; but the hypocausts, baths, and other underground
buildings were found tolerably perfect, being filled with stones, broken
tiles, rubbish and soil. The old floors of various rooms were covered
with rubble. As I was anxious to know how thick the mantle of mould and
rubbish was, which had so long concealed these ruins, I applied to Dr. H.
Johnson, who had superintended the excavations; and he, with the greatest
kindness, twice visited the place to examine it in reference to my
questions, and had many trenches dug in four fields which had hitherto
been undisturbed. The results of his observations are given in the
following Table. He also sent me specimens of the mould, and answered,
as far as he could, all my questions.
MEASUREMENTS BY DR. H. JOHNSON OF THE THICKNESS OF THE VEGETABLE MOULD
OVER THE ROMAN RUINS AT WROXETER.
Trenches dug in a field called “Old Works.”
Thickness of mould in inches.
1. At a depth of 36 inches 20
undisturbed sand was reached
2. At a depth of 33 inches 21
concrete was reached
3. At a depth of 9 inches 9
concrete was reached
Trenches dug in a field called “Shop Leasows;” this is the highest field
within the old walls, and slopes down from a sub-central point on all
sides at about an angle of 2°.
Thickness of mould in inches.
4. Summit of field, trench 45 40
inches deep
5. Close to summit of field, 26
trench 36 inches deep
6. Close to summit of field, 28
trench 28 inches deep
7. Near summit of field, trench 24
36 inches deep
8. Near summit of field, trench 24
at one end 39 inches deep; the
mould here graduated into the
underlying undisturbed sand, and
its thickness (24 inches) is
somewhat arbitrary. At the other
end of the trench, a causeway was
encountered at a depth of only 7
inches, and the mould was here
only 7 inches thick
9. Trench close to the last, 28 24
inches in depth
10. Lower part of same field, 15
trench 30 inches deep
11. Lower part of same field, 17
trench 31 inches deep
12. Lower part of same field, 28
trench 36 inches deep, at which
depth undisturbed sand was
reached
13. In another part of same 9½
field, trench 9½ inches deep
stopped by concrete
14. In another part of same 9
field, trench 9 inches deep,
stopped by concrete
15. In another part of the same 16
field, trench 24 inches deep,
when sand was reached
16. In another part of same 13
field, trench 30 inches deep,
when stones were reached; at one
end of the trench mould 12
inches, at the other end 14
inches thick
Small field between “Old Works” and “Shop Leasows,” I believe nearly as
high as the upper part of the latter field.
Thickness of mould in inches.
17. Trench 26 inches deep 24
18. Trench 10 inches deep, and 10
then came upon a causeway
19. Trench 34 inches deep 30
20. Trench 31 inches deep 31
Field on the western side of the space enclosed within the old walls.
Thickness of mould in inches.
21. Trench 28 inches deep, when 16
undisturbed sand was reached
22. Trench 29 inches deep, when 15
undisturbed sand was reached
23. Trench 14 inches deep, and 14
then came upon a building
Dr. Johnson distinguished as mould the earth which differed, more or less
abruptly, in its dark colour and in its texture from the underlying sand
or rubble. In the specimens sent to me, the mould resembled that which
lies immediately beneath the turf in old pasture-land, excepting that it
often contained small stones, too large to have passed through the bodies
of worms. But the trenches above described were dug in fields, none of
which were in pasture, and all had been long cultivated. Bearing in mind
the remarks made in reference to Silchester on the effects of
long-continued culture, combined with the action of worms in bringing up
the finer particles to the surface, the mould, as so designated by Dr.
Johnson, seems fairly well to deserve its name. Its thickness, where
there was no causeway, floor or walls beneath, was greater than has been
elsewhere observed, namely, in many places above 2 ft., and in one spot
above 3 ft. The mould was thickest on and close to the nearly level
summit of the field called “Shop Leasows,” and in a small adjoining
field, which, as I believe, is of nearly the same height. One side of
the former field slopes at an angle of rather above 2°, and I should have
expected that the mould, from being washed down during heavy rain, would
have been thicker in the lower than in the upper part; but this was not
the case in two out of the three trenches here dug.
In many places, where streets ran beneath the surface, or where old
buildings stood, the mould was only 8 inches in thickness; and Dr.
Johnson was surprised that in ploughing the land, the ruins had never
been struck by the plough as far as he had heard. He thinks that when
the land was first cultivated the old walls were perhaps intentionally
pulled down, and that hollow places were filled up. This may have been
the case; but if after the desertion of the city the land was left for
many centuries uncultivated, worms would have brought up enough fine
earth to have covered the ruins completely; that is if they had subsided
from having been undermined. The foundations of some of the walls, for
instance those of the portion still standing about 20 feet above the
ground, and those of the marketplace, lie at the extraordinary depth of
14 feet; but it is highly improbable that the foundations were generally
so deep. The mortar employed in the buildings must have been excellent,
for it is still in parts extremely hard. Wherever walls of any height
have been exposed to view, they are, as Dr. Johnson believes, still
perpendicular. The walls with such deep foundations cannot have been
undermined by worms, and therefore cannot have subsided, as appears to
have occurred at Abinger and Silchester. Hence it is very difficult to
account for their being now completely covered with earth; but how much
of this covering consists of vegetable mould and how much of rubble I do
not know. The market-place, with the foundations at a depth of 14 feet,
was covered up, as Dr. Johnson believes, by between 6 and 24 inches of
earth. The tops of the broken-down walls of a caldarium or bath, 9 feet
in depth, were likewise covered up with nearly 2 feet of earth. The
summit of an arch, leading into an ash-pit 7 feet in depth, was covered
up with not more than 8 inches of earth. Whenever a building which has
not subsided is covered with earth, we must suppose, either that the
upper layers of stone have been at some time carried away by man, or that
earth has since been washed down during heavy rain, or blown down during
storms, from the adjoining land; and this would be especially apt to
occur where the land has long been cultivated. In the above cases the
adjoining land is somewhat higher than the three specified sites, as far
as I can judge by maps and from information given me by Dr. Johnson. If;
however, a great pile of broken stones, mortar, plaster, timber and ashes
fell over the remains of any building, their disintegration in the course
of time, and the sifting action of worms, would ultimately conceal the
whole beneath fine earth.
* * * * *
_Conclusion_.—The cases given in this chapter show that worms have played
a considerable part in the burial and concealment of several Roman and
other old buildings in England; but no doubt the washing down of soil
from the neighbouring higher lands, and the deposition of dust, have
together aided largely in the work of concealment. Dust would be apt to
accumulate wherever old broken-down walls projected a little above the
then existing surface and thus afforded some shelter. The floors of the
old rooms, halls and passages have generally sunk, partly from the
settling of the ground, but chiefly from having been undermined by worms;
and the sinking has commonly been greater in the middle than near the
walls. The walls themselves, whenever their foundations do not lie at a
great depth, have been penetrated and undermined by worms, and have
consequently subsided. The unequal subsidence thus caused, probably
explains the great cracks which may be seen in many ancient walls, as
well as their inclination from the perpendicular.