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Chapter IV
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 debris 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.
Archaeologists 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 Elie
de Beaumont, who, in discussing this subject, says, "pour une
voiture de materiaux qui en sort, on y en fait entrer cent." {53}
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 2.5 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 tesserae (small red tiles), and surrounded on two
sides by broken-down walls, was soon discovered. It is believed,
{54} 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 degrees; 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 degree, and in one place near the outside at as much as
8 degrees 30 minutes. 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.
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 6.5 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 tesserae torn up, and the
tops of the old walls knocked down.
When the concrete and tesserae 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 tesserae. 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 48.5, and another at 51.5 inches
beneath the surface. A fresh humus-lined burrow was also met with
at a depth of 57 and another at 65.5 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 6.75, 10 and 11.5 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 5.5 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
2.75 inches, and this rested on a layer from 8.75 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. {55}
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 degrees;
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 1.5 mile in compass, now surrounds a space of about 100
acres of cultivated land, on which a farm-house and a church stand.
{56} 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
tesserae, 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.
A section across the middle of another hall in the Basilica, 32
feet 6 inches in length, called the AErarium, 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.
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.
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 debris, the lower one of which rested
on a floor with tesserae. 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.
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 tesserae
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 tesserae. 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 49.5 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 5.75 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 tesserae appeared as if drawn a little away
from the walls; whilst in other places they were still in close
contact with them.
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 0.75 of an inch above its level. The
field, which was in pasture, here sloped from north to south, at an
angle of 30 degrees, 40 seconds. 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 debris,
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 7.75 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.
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 28.5 inches, and
at the eastern end by a thickness of only 11.5 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 30 degrees 40 seconds,
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
(25.5 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 25.5-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 1 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 shown in parenthesis--DP.)
1. At a depth of 36 inches undisturbed sand was reached (20)
2. At a depth of 33 inches concrete was reached (21)
3. At a depth of 9 inches concrete was reached (9)
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 degrees.
4. Summit of field, trench 45 inches deep (40)
5. Close to summit of field, trench 36 inches deep (26)
6. Close to summit of field, trench 28 inches deep (28)
7. Near summit of field, trench 36 inches deep (24)
8. Near summit of field, trench 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 (24)
9. Trench close to the last, 28 inches in depth (24)
10. Lower part of same field, trench 30 inches deep (15)
11. Lower part of same field, trench 31 inches deep (17)
12. Lower part of same field, trench 36 inches deep, at which
depth undisturbed sand was reached (28)
13. In another part of same field, trench 9.5 inches deep stopped
by concrete (9.5)
14. In another part of same field, trench 9 inches deep, stopped
by concrete (9)
15. In another part of the same field, trench 24 inches deep, when
sand was reached (16)
16. In another part of same 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 (13)
Small field between "Old Works" and "Shop Leasows," I believe
nearly as high as the upper part of the latter field.
17. Trench 26 inches deep (24)
18. Trench 10 inches deep, and then came upon a causeway (10)
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.
21. Trench 28 inches deep, when undisturbed sand was reached (16)
22. Trench 29 inches deep, when undisturbed sand was reached (15)
23. Trench 14 inches deep, and then came upon a building (14)
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 degrees, 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.
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