THE WATERS
_THE WATERS ABOVE THE FIRMAMENT_
RATIONALISTIC BELIEFS
“And God made the firmament and divided the waters which were under the
firmament from the waters which were above the firmament” (Gen. i, 7).
We saw in Chapter II that this text had induced many of the earlier
Church Fathers to devise strange theories about the waters above the
firmament. The idea of Jerome, Josephus, Ambrose, Isidore, and Bede that
these waters were in crystalline, or frozen, form met with opposition
from those who were influenced by classical science and especially by
the writings of Aristotle. Abelard in his _Expositio in hexaemeron_[818]
discussed in considerable detail various opinions about the existence of
solidified water above the firmament, though personally he was inclined
to think that the air sustains the water in the form of very fine drops.
That much heavier objects may sometimes be supported by air or water he
proved by citing examples of cases where this is actually known to
happen, as where a needle may be made to float on water. Theodoric of
Chartres and William of Conches approached the problem from an even more
rationalistic standpoint. Theodoric[819] held that water, when subjected
to sufficient heat, turns into “pure air.” On the second day of the
Creation the fire element heated the water element in such a way that
large portions of the latter rose as high as the moon and were there
suspended in vaporous form “above the top of the sky” (_super summam
coeli_). As a result the atmosphere became intercalated between the
liquid water of the earth’s surface and this water vapor above the
firmament. The firmament itself, Theodoric contended, was merely the air
and was so called either because it “firmly” supported that which was
above it and enclosed that which was below it or else because it
“firmly” gripped the earth on all sides. William of Conches also argued
against the possibility of frozen water above the firmament.[820] This,
he declared, is quite contrary to reason: frozen water is solid and
heavy, and the place for solid and heavy substances in the constitution
of the universe is either on or beneath the earth’s surface. Then again,
water in or near the celestial sphere—which is the abode of fire—would
either extinguish the fire or else itself be consumed. William objected
to juggling with the Aristotelian laws of physics. He explained the
Biblical text by asserting that the firmament is the atmosphere and that
the waters “above” it are in reality nothing more than the clouds within
it.[821] On the whole, he concluded that the text should be interpreted
allegorically rather than literally.
LITERAL BELIEFS
In decided contrast with these more or less rationalistic theories was
Michael Scot’s bold assertion that beyond the realm of fire and above
the eighth heavenly sphere comes a “multitude of waters,”[822] or
Gervase of Tilbury’s extraordinary account of a sea either in or above
the atmosphere. To prove the existence of such a sea Gervase told[823]
how “in his time some people coming out of a church in England found an
anchor let down by a rope out of the heavens, how there came voices from
sailors above trying to loose the anchor, and, finally, how a sailor
came down the rope, who, on reaching the earth, died as if drowned in
water” (White).[824] William of Auvergne, Platonist of the early
thirteenth century and staunch opponent of Aristotelianism, also found
no difficulties in the way of literal belief in the waters above the
firmament. Ignoring the arguments of Peripatetic physics, he wrote:[825]
“Nobody in the world is either amazed or horrified at the presence of
fire beneath the waters and more especially beneath the earth. This is
proved to the eye by the fiery outbreaks from three mountains (that is
Vulcano, Etna, and Chimaera). Why then should one wonder so much that
water is found above the heavens?”
Hildegard of Bingen gave expression to some views, probably original
with her, regarding the waters above the firmament. In the _Causae et
curae_ she speaks of “the waters of the great sea which surrounds the
world and forms as it were a flank to those waters which are above the
firmament, because the height (_summitas_) of those which are above and
the extreme edge (_extremitas_) of those which are below the firmament
are mutually joined together.”[826] In the _Solutiones_ she
characterized the celestial waters, asserting that they neither increase
nor decrease (implying perhaps that they are disturbed by no tides) but
that they have remained just as they are now since God created them.
They are unlike the waters of the earth inasmuch as they are far more
fine in texture and entirely invisible to human eyes.[827]
PURPOSE OF THE WATERS
What purpose is served by the waters above the firmament? Gervase of
Tilbury declared that they supply the earth with dew.[828] Abelard said
that there were two opinions on this subject.[829] The first was that
the waters were originally placed in the heavens in order to be used in
the Deluge. To this he was opposed, because the Psalms show that the
waters were still in existence in David’s time, long after the Flood. If
there had not been waters above the firmament in David’s time, how could
the latter have sung: “Praise ye the Lord ... ye heavens of heavens and
let all the waters that are above the heavens praise the name of the
Lord”?[830] Abelard was more inclined to favor the second theory, that
the waters were intended to temper the heat of the upper celestial
fires. He felt, however, with more or less reason, that this entire
problem presents great, if not insoluble, difficulties.
_THE CONGREGATION OF WATERS_
There is an abundance of evidence that the authority of the Bible was
invoked to support a theory that the waters beneath the firmament must
constitute one unit, or “congregation of waters.” This view, as we saw
in Chapter II, was based on the assertion in Genesis that God “gathered
together the waters in one place.” Peter Abelard,[831] Peter
Comestor,[832] and Hugh of St. Victor[833] all maintained that there are
great subterranean reservoirs connected with the seas and rivers of the
surface in such a way that the whole hydrographic system of the earth
forms a single unit. Prior to the action of God in gathering them
together these waters in the primordial chaos were supposed to have been
disseminated in the form of vapor, which took up vastly more room than
the liquid into which God’s power later concentrated them.
CONNECTION BETWEEN SEAS AND RIVERS
That many writers believed in the connection between the seas and the
rivers and in the consequent unity of the waters is shown by numerous
passages. Medieval thinkers, as we have seen, were constantly
preoccupied by the doctrine of the microcosm, the theory that the human
body includes all the elements which constitute the universe and is
indeed in itself a miniature replica of the universe. This appears in a
statement in the _De imagine mundi_ that the whole interior of the earth
is filled with channels like the blood vessels that permeate the
body.[834] Whenever and wherever a man digs into the ground he is sure
to find water. A constant circulation is maintained between the ocean
and the waters of the surface of the land through these passages and
through the air.[835]
William of Conches held that the great ocean in the equatorial zone is
the source of all dampness in the earth (_fons humoris_) and that the
land is seamed with canals full of water derived from that source.[836]
Peter Alphonsi describes the circulation of the waters from the sea into
the atmosphere by evaporation, thence in the form of rain to the rivers,
and so back to the sea.[837] Peter Comestor, however, held that the
river which springs from Paradise and divides in four is the source of
all the water of the earth;[838] and Gervase of Tilbury, who follows
Comestor in this respect, mentions in another connection that springs
have their sources in the sea.[839] Perhaps if he had analyzed the
question he would have said that the waters of the sea must find their
way at some time through the rivers of Paradise and thence to the
springs.
THE EARTH ESTABLISHED ON THE WATERS
The phrase in the Psalms, that God established the earth above or on
(_super_) the waters,[840] also proved puzzling to the thinkers of our
period. The easy explanation that such a phenomenon might be due to the
arbitrary working of God’s will was not always readily accepted. Some
commentators on the Psalms observed dubiously that it surpassed their
understanding.[841] Alexander Neckam stated that it might possibly refer
to waters beneath the earth, since “Alfraganus [Al-Farghānī] says that
the sphere of the waters and of the earth are one.” Saints who had
expounded the phrase, he added, tried to explain away the difficulty by
referring to the colloquial manner of saying that Paris is founded “on
the Seine.” “The truth of the matter, however, is that the terrestrial
paradise is above the waters, since it is above the sphere of the
moon.”[842] An allegorical interpretation was also resorted to, and the
reader was told to conceive of “earth” as being the Church and “the
waters” as the many peoples upon which the Church is founded.
Peter Abelard, in an interesting passage in the _Expositio in
hexaemeron_,[843] gave an interpretation of this phrase as well as of
the text about the “congregation of the waters” which seems to
foreshadow a theory later to be elaborated by Brunetto Latino and
destined to gain a firm grip on the hydrographical conceptions of many
individuals until as late as the eighteenth century. Abelard wrote:
“When the waters receded into one part of the earth, the other parts
were uncovered, as was written: ‘God, who established the earth on the
waters.’ As any globe may be immersed in water in such a way that one
part of it rises above the water, even so the globe of the earth rests
in the waters so that one side of it is contiguous with the sea and
causes the sea to permeate through its veins, whence springs and rivers
take their rise. The waters of this sea, in truth, are congregated into
one place and are consequently deeper than if they were diffused,
unless, perchance, the fact that they may be drawn off through the veins
of the earth makes them less deep.” We have seen that Abelard and
William of Conches compared the universe to an egg in which the four
parts correspond to the four elements, fire, air, water, and earth.[844]
This was the theoretical arrangement of the elements according to the
logical application of Aristotle’s physical laws. As a matter of fact,
the aqueous sphere does not completely envelop the earth, as it should
if this theoretical arrangement were carried out in nature. How, then,
could it be explained that a portion of the earth’s surface is not
covered by water? Robert Grosseteste, without attempting a physical
explanation, answered this question from the teleological point of view,
echoing the words of Genesis. “Truly it is a fact,” he wrote, “that, in
order that the animals of this earth might have a habitation and refuge,
the water receded into the concave parts of the earth and the surface of
the land appeared dry and distinct. And so the land with the waters
contained upon it is like a sphere of earth.”[845] Later writers were
not willing to accept such a simple declaration and looked for physical
and mechanical explanations. For instance, Brunetto Latino assigned to
the spheres of earth and of water each a different center, placed in
such positions in relation to one another that the aqueous sphere covers
the sphere of earth to a great depth on one side (the southern
hemisphere) but on the opposite side leaves dry the portion inhabited by
man.[846] Certainly the passage we have quoted above shows that Abelard
may well have had something of this sort in mind.
_THE OCEANS AND SEAS_
RELATIVE AREAS OF LAND AND SEA
We saw in Chapter I that two theories prevailed in ancient times as to
the distribution of land and water: the oceanic theory, that the
_oikoumene_ is surrounded by water; and the continental theory, that the
oceans of the earth occupy relatively small and enclosed basins. Though
the writers of our period held to the oceanic hypothesis, they had
various and conflicting notions in regard to the size of the ocean or
oceans which surround the known world. The great popularity of Martianus
Capella and Macrobius, who both held the doctrine that there are three
areas of land corresponding to our _oikoumene_ in the three quarters of
the earth’s surface, must have rendered impossible any widespread
acceptance of a theory like the one hinted at by Abelard, that all of
the earth’s surface except the _oikoumene_ is covered by water; and the
definition of the ocean as a zone or hem surrounding the inhabited
world, not infrequently given in our period, certainly does not imply
the existence of water areas of immense size in comparison with the land
areas.[847] Furthermore, the Second Book of Esdras, which, though
apocryphal, enjoyed high authority in the Middle Ages,[848] gave the
reader an opposite impression. Here it was stated: “Upon the third day
thou didst command that the waters should be gathered in the seventh
part of the earth: six parts hast thou dried up, and kept them, to the
intent that of these some being planted of God and tilled might serve
thee.” “Upon the fifth day thou saidst unto the seventh part, where the
waters gathered, that it should bring forth living creatures, fowls and
fishes: and so it came to pass.” Roger Bacon uses this text from Esdras
to reinforce his argument that, relatively speaking, the water surface
of the world is very restricted in comparison with the land
surface.[849]
EXPLANATION OF UNIFORM LEVEL OF SEA SURFACE
Into the sea there pours at all times a vast volume of water from the
rivers. Neckam moralized mournfully on this[850] and compared the flow
of fresh water into the salt depths with the way in which greater powers
absorb lesser and the way in which the voluptuousness of this world—a
sham sweetness—is turned to bitterness and salt; but he did not attempt
to explain the puzzling physical problem of why the surface of the sea
fails to rise and overflow the lands.[851] Most writers who dealt with
the latter problem appealed to the theory of the _congregatio aquae_:
since all the waters of the earth form one unit, they must inevitably
make their way back from the sea through various routes to the sources
of streams.[852] Other explanations, however, were sometimes brought
forward. Adelard of Bath believed that the stars and sun absorb a
certain amount of water.[853] The author of the _De imagine mundi_ was
convinced that the fresh water entering the sea is partially consumed by
the salt of the deeps and partially evaporated by the winds and taken up
into the sun.[854]
SALINITY OF THE SEA
The two characteristics of the oceans that distinguish them from bodies
of fresh water and have always aroused men’s curiosity are their
saltness and their tides. The _De imagine mundi_ gives a popular
etymology of the word _mare_ from _amarum_, meaning bitter or
salty.[855] Though there is no attempt in this book to show reasons for
the salinity of the sea, the author followed Isidore and Bede in the
opinion that the water at great depths is more bitter and salt than near
the surface and that evaporation draws off the fresh water only and
leaves the bitter and dense elements behind; similarly, that part of the
sea water makes its way back to the sources of the springs, deposits its
salt in the land, and bursts forth fresh and purified from its passage
through the earth. In the _Image du monde_, on the other hand, there is
a naïve explanation of why the sea is salt.[856] Great saline mountains
in the deeps are said to be constantly dissolving away and thereby
imparting a peculiar character to the water. Adelard of Bath, Gervase of
Tilbury, and William of Conches treated the subject a shade more
rationally, perhaps, in attributing the saltness to the influence of
heat. Adelard says,[857] “I consider the cause of the saltness of the
sea to be the heat of the sun and planets. For, since the true ocean
passes through the heart of the torrid zone and since the course of the
planets runs through the same zone, though obliquely, the ocean must of
necessity be heated by such a great heat of the heavenly bodies that it
is thereby rendered salt.” This explanation, he adds, is even subject to
proof: for along coasts nearest the ocean, sea water “when dried in the
sun on the rocks” may readily be converted into salt without any
artificial aid; in more distant seas the water must be boiled and
reboiled before this effect is produced. Furthermore, in summer all sea
water is salter than in winter.
William of Conches[858] and Alexander Neckam[859] also followed
Aristotle in believing that water in its purest form has an insipid
taste but that it is thickened and rendered salt by the sun’s heat in
the torrid ocean, whence it is distributed to the other seas by
currents. Gervase of Tilbury tends to exaggerate this theory: we read in
the _Otia imperialia_[860] of a lake in the County of Aix, near Arles,
the waters of which are congealed into ice by the cold of winter and
into salt by the heat of August. This led Gervase to conclude that it
would be impossible to sail around the earth, because the all-encircling
ocean would be frozen stiff in the north and thickened into solid salt
in the south.
TIDES
If we discard fanciful ideas like that of Richard, prior of St. Victor
in Paris (died 1173), to the effect that the tides are produced by the
breathing of some great submarine monster or spirit,[861] we find two
distinct groups of tidal theories prevalent in the twelfth century: as
Duhem defines them, the physical and the astrological. The astrological
theories, which explained the tides by the influence of the moon, had
been expounded before the period we are studying by Posidonius, Pliny,
Bede, and the Moslem Abū Maʿshar. The physical theories had been set
forth by Macrobius, who had believed that the tides were due to the
impact of ocean currents, and Paul the Deacon, who had attributed them
to the action of great whirlpools. Although twelfth-century students
added little to these earlier opinions, they made some remarkable
combinations of them, and their observations were distinguished by a few
close records of actual tidal phenomena.[862]
_Lunar Causation_
Bernard Sylvester explained the tides by lunar causation alone[863] and
attributed to the moon the power of attracting and repelling not only
the waters but also terrestrial substances,[864] inasmuch as the moon is
the nearest planet to the earth, the largest, and consequently the most
powerful.[865]
In the following century we find that Robert Grosseteste saw in the
effects of lunar rays upon the bottom of the sea sufficient cause for
the ebb and flood. If in their broad outlines the ideas of the bishop of
Lincoln are plain enough, the individual steps of his argument are
neither clear nor coherent. They are of sufficient interest,
nevertheless, to justify an attempt at interpreting them.[866] We have
already alluded to Robert’s theory of rays emanating from the celestial
bodies in the shape of cones or “pyramids” and to his principle that the
power of these rays is inverse to the obliquity of the angle at which
they meet the earth’s surface and to the length of the pyramids.[867]
When the moon is rising, Grosseteste explains in the _De natura
locorum_,[868] the rays are very oblique and the pyramids long: hence
the power of the rays is much too weak to disperse vapors that have
accumulated on the sea floor or to draw these vapors up into the air.
The result is that the vapors tend to displace the waters in the depths,
to rise in bubbles to the surface, and thus to produce flood tides. As
the moon approaches the meridian the rays become less oblique, the
pyramids shorter, and the lunar power consequently greater. The moon now
disperses and consumes the vapors and draws them up into the air from
the depths of the sea. By the time our satellite reaches the meridian,
the vapors are entirely consumed, “and, since the cause ceases, the
effect also ceases; and the waters of the sea naturally flow back into
their proper place in order not to create a vacuum.” Hence the ebb
begins.
Grosseteste does not make clear what generates the vapors, though he
probably meant us to assume that they were produced by the heat due to
the reflection of the moon’s rays upon the sea floor. In another
treatise, the _De impressionibus elementorum_,[869] he explains how
reflected rays, though not necessarily the rays of the moon, in passing
through a transparent body of water may create heat at the bottom.
The problem of the flood tide when the moon is in the opposite
hemisphere of the heavens still remained. Grosseteste’s obscure
explanation of this runs about as follows: “Many try to give a reason
for this difficult circumstance on the grounds that opposite quarters of
the universe are of the same composition (_commixtionis_) and
consequently produce the same effects. But this explanation falls short,
since it is false to assert that there are any actual replicas of the
stars of one quarter of the heavens in another quarter, inasmuch as the
earth interposes its bulk between a planet in one quarter and the
quarter opposite. Moreover, even were this explanation true, an
explanation of the original cause would be required. That is to say, it
would be necessary to ask why the opposite quarters are of the same
composition and consequently exert the same effect. The fact is that the
reflection of rays solves this problem, since the rays of the moon are
multiplied on the stellar heaven. Because the stellar heaven is an
opaque body, we are consequently not able to see it, though it
nevertheless is very luminous according to Alpetragius and
Messalahe [_sic_]. Other reflected rays fall on the opposite quarter at
right angles.”[870]
_Terrestrial Causation_
Most writers found that the astrological, or lunar, theory alone was
insufficient to explain all the peculiarities of the tides and made
appeal, as well, to physical theories—in particular to that of
Macrobius. This is given in varying terms by Adelard of Bath, Lambert of
St. Omer, William of Conches, and Giraldus Cambrensis. Macrobius, as we
have already observed, had conceived of four ocean currents issuing out
of the great equatorial ocean and flowing north and south in the
girdling ocean which includes the poles.[871] These currents run
together somewhere in the polar regions; the waters rebound on
themselves (_ex repercussione ingurgitur retro mare_) and in this way
cause the ebb and flow. Lambert of St. Omer in his _Liber floridus_
seems to have accepted the Macrobian theory much as it stands,[872] but
Adelard harbored doubts as to the sufficiency of the impact of the
waters against each other to produce a tidal rebound and thought that
some mountain or other mass of land must interpose to produce such an
effect.[873]
William of Conches cites two theories of tidal controls:[874] the first
is that of Macrobius; the second, confusingly stated, suggests Adelard’s
hypothesis of an interposing mass of land. William says, in effect, that
the tides are due in part to the existence of mountains submerged
beneath the sea, against which the waters are attracted forward and then
repelled, producing an oscillating motion. As to this, we may well be
led to inquire how Macrobius, Adelard, and William explained this
oscillating motion, for certainly two steadily flowing currents meeting
each other or running against submerged reefs would not create any such
motion. Unfortunately in this we are left unsatisfied by our medieval
writers, who characteristically here, as often elsewhere, were content,
when stating that one phenomenon causes another, to leave entirely to
the imagination the explanation of the manner in which such causation is
actually effected.
William did not rule out all lunar control over the ebb and flood but
explained the spring and neap tides by variations in the moon’s power of
heating and drying the atmosphere. This power, he thought, is at a
minimum both when the moon is full and when it is new. Consequently we
have high spring tides at these times, and vice versa. William’s theory
is the reverse of Abū Maʿshar’s:[875] that the tides are caused by the
active attraction by the moon of the humid elements on the earth’s
surface. William fails to show us why the tides should be in flood when
the moon is rising toward the meridian and why spring tides should occur
when there is a full moon. Abū Maʿshar, on the other hand, fails to
explain why there is a flood tide when the moon is on the other side of
the earth, in the opposite celestial hemisphere.
Alexander Neckam gives what is, to say the least, an unsatisfactory
treatment of the tides.[876] After quoting the scientific opinions of
others, he remarks that to explain the ebb and flow of the waters is a
problem that cannot be solved. Then, in his customary vein, he adds the
moral observation that the tides are like the persecutions of the
Christians and that they should not fill one with too much despair, for
after they have risen they always subside again in the due course of
time.[877]
William the Breton wondered at the tides but, like Neckam, refrained
from trying to explain their cause and said that God alone understands
this and no man can comprehend it either now or ever.[878] He was amazed
that such a wide, deep, and powerful stream as the Seine at Rouen could
be forced back upon itself by the waters of the sea and made to flow in
the opposite direction through a space of land across which its normal
current could scarcely pass in three days. Was this due to the fact that
fresh water is less powerful than salt? Or does the fresh water find the
salt water odious and recoil before it? Or does the stream do reverence,
as it were, to its mother, the sea, falling back before her and then
when the tide turns following behind her respectfully? None of these
explanations was William ready to accept as true. “For us who live our
human lot here below, it is sufficient to know the fact; it is not
allowed to us to know the cause.”[879]
_Giraldus Cambrensis’ Tidal Studies_
The most elaborate tidal studies of our period are in the pages of
Giraldus Cambrensis’ _Topographia Hiberniae_, where we find a
combination of the astrological theory of Abū Maʿshar, the whirlpool
theory of Paul the Deacon, and the ocean-current theory of Macrobius.
Giraldus said that when the moon passes the meridian the waters begin to
recede from the coasts of Britain and to retire into hidden submarine
reservoirs.[880] The moon, being the heavenly body that controls all
things humid on the earth, when full causes the tides to rise to unusual
heights. A little further on in his discussion, Giraldus explains that
at the four opposite parts of the ocean there is a force that violently
attracts the sea water, producing a sort of periodic swelling and
sinking; this is connected in some manner with a belief in Giraldus’
mind that greater quantities of fresh water enter the sea at the
extremities of the earth and in the vicinity of the poles than
elsewhere, though on what he based this supposition and how it produced
the results which he ascribes to it, he does not explain. Giraldus’
theory also owes much to Macrobius’ hypothesis of the effects of the
collision of ocean currents on the tides, as well as to Paul the
Deacon’s whirlpool theory, for he explains elsewhere[881] that
philosophers mention the existence of four whirlpools at the opposite
ends of the earth and that some people attribute to these the causation
of tides and storms of wind. Each of the whirlpools resembles a great
vortex in the northern seas towards which the waters of the sea rush
together, to be absorbed in secret caverns as if in an abyss; ships
approaching too near are sucked in and destroyed.
The most interesting feature of Giraldus’ tidal studies, however, are
not these general speculations regarding causes but some very neat
observations made on the British and Irish coasts. In the first place,
he remarks on the choppy water of the Irish Sea, which presumably he
connects with tide rips.[882] He then goes on to discuss the difference
in the hour of high water at various Irish ports, at Milford Haven in
Wales, and at Bristol in England. When the tide is at the half-ebb in
Dublin, at Milford Haven it is at the half-flood, and near Bristol just
beginning the rise. Let us see what the facts of the case are at the
present day.[883] On February 1, 1919, half-ebb occurred at Dublin at
about 2:30 P. M., half-flood at Milford Haven only about an hour and a
half later, and low water had occurred at Bristol half an hour earlier.
In other words Giraldus’ observations on the relative times of the tides
at these three points were unusually accurate. Furthermore, he explains
that at Wicklow, on the Irish coast opposite Wales, the water falls at
the same time that it rises throughout the sea in general. When Giraldus
here speaks of the “sea in general” he perhaps had in mind tidal
observations made at other points on the coast not far to the south.
Modern tide tables show that near Arklow, only about fourteen miles
away, it is low water some two hours and a half earlier than at Wicklow.
The water, consequently, is rising at Arklow for two hours and a half
while it is still falling at Wicklow. That Giraldus was familiar with
Arklow is shown by the fact that he mentions a river entering the sea
there and describes a curious rock in the harbor.[884]
Finally, Giraldus states[885] that when the moon has passed the meridian
the waters first recede from the coasts of Britain but that on the Irish
coasts in the vicinity of Dublin full flood corresponds to this
recession of the waters. In the vicinity of Wexford, however, flood
waters do not correspond with the flood at Dublin but rather with the
flood waters on the British coast at Milford Haven. Giraldus was
mistaken, if we are right in interpreting his words to mean that he
thought that the tidal undulation which produces high water at Dublin is
a different wave from that of Wexford or Milford Haven. No tidal
undulation enters the Irish Sea from the north, and consequently the ebb
and flood at all of these places is caused by the same wave. On the
other hand, this wave reaches Dublin nearly five hours later than it
reaches Wexford and Milford on the opposite shore, and the accuracy of
Giraldus’ data on the time of these tides is further confirmed by modern
tide tables, which show that flood water at the Welsh port may occur
only twenty-four minutes earlier than at Rosslare Point, the entrance to
Wexford Harbor.
It would be interesting if we could know how Giraldus gathered these
data. Probably they were pieced together from incidental observations of
sailors or fishermen, for certainly no systematic investigation of tidal
phenomena could well have been undertaken at Giraldus’ time.[886] It is
typical of an immense amount of close and accurate knowledge that has
always existed along with ignorance and superstition among the more
humble workers of this world, knowledge that until recent years has but
rarely found literary expression.
OTHER MARINE PHENOMENA NOTED BY GIRALDUS
Giraldus certainly was not always so fortunate in his discussion of
marine phenomena. He taxes our credulity a little when he tells of a
rock in Arklow harbor on one side of which the water rises while it is
falling on the other,[887] though this may perhaps have resulted from
some local play of currents and eddies. It is less easy to find an
explanation of a story which he relates of a recession of the sea at
“Crebonensus” (Proconnesus?) near Constantinople.[888] Here, during
eight days at the time of the festival of St. Clement, the waters fell
back in order to allow pilgrims to go to the saint’s shrine. This kind
of miracle, to be sure, had the support of Biblical authority in the
story of the parting of the waters of the Red Sea to permit the passing
of the children of Israel; and we find a similar tale in the _Otia
imperialia_,[889] where Gervase asserts that the Sea of Pamphylia was
divided for Alexander the Great, because God wished to destroy the
Persian kingdom by means of the Macedonian. The lake (or river) which in
the legend surrounded the church of St. Thomas in India was also said to
go dry at regular intervals to permit pilgrims to approach.[890]
In his description of South Wales, Giraldus Cambrensis gives an account
of marine encroachments on the land and perhaps of coastal subsidence. A
great storm on this sandy coast laid bare a forest hitherto covered by
the waters. Trunks of trees appeared with marks of the ax upon them,
fresh as if cut only the day before. Giraldus was convinced that the
marks dated from inconceivable antiquity, perhaps even from the time of
the Flood.[891] The wood was overwhelmed, he said, by the constant and
ever increasingly violent advance of the sea; and certainly it is well
known in modern days that the waves long have been eating into the coast
of Pembrokeshire and that the uncovering by storms of buried forests and
stumps is a commonplace occurrence there. Perhaps we are justified in
interpreting Giraldus’ remarks by assuming that the forest had not, as
he states, previously been covered by water but more probably by marine
sands or muds, which subsequently were removed from the stumps by storm
waves.
ST. BRANDAN AND THE SPIRIT OF THE SEA
Less scientific—or perhaps we had better say less prosaic—than the
writings we have just been discussing but fully as replete with
understanding of the ocean and its various moods, is the legend of the
wanderings of St. Brandan. The style and spirit of this entire story
shows that it must have been composed by men filled with a sense of the
immensity and mystery of the Atlantic.[892] Probably the tale had its
roots in the reports of actual voyagings of Irishmen blown far out to
sea. Although there is much of the marvelous and supernatural borrowed
from older tradition, the tone of the legend as a whole rings true to
nature. Certainly it was not written by a landsman. At one time St.
Brandan and his companions sailed north for three days, and the sea
became “as it were coagulated through an excess of calmness.”[893] It
has been suggested that this refers to the semi-solid “Liver Sea” of
Germanic legend, itself perhaps an echo of the reports of Pytheas and
other classical writers about clotted sea waters north of Thule and in
the Western Ocean.[894] On another occasion the travelers came in sight
of a high column of clearest crystal apparently not far away, though it
took three days to reach it.[895] So great was its height that they
could scarce discern the summit, and as they drew near they saw that it
was covered by a silvery canopy of marvelously fine texture. They passed
through a hole in the canopy and entered a sea whose waters were so
clear that the base of the column could be seen resting on the earth at
the bottom of the sea. For an entire day they sailed along one side of
the column. If we discard from all this what is obviously fabulous or
borrowed from the vision of Ezekiel[896] or from the description of the
New Jerusalem in Revelation,[897] may we not be justified in supposing
that the sight of a great iceberg flashing in the sun gave rise to the
story of the crystalline column and that the canopy represented curtains
of fog hanging about its flanks?
St. Brandan and his crew also had other glimpses of the bottom of the
sea[898] through waters of such remarkable transparency that they
thought they could almost touch the beasts of various kinds lying there.
When mass was said on board, these beasts rose and circled about the
ship but did not molest the saint and his party. After seven days’
voyage with sails set they had scarcely crossed this stretch of
translucent water.
BOTTOM OF THE SEA
We find other accounts of the bottom of the sea and even of visits made
to it, in the legendary writings of our period. Gervase of Tilbury[899]
tells of an individual named Nicholas Pappas, a dweller on the shores of
the Strait of Messina, who was forced by King Roger II of Sicily to dive
into the waters. Being well known to the submarine monsters, he escaped
all danger from molestation by them and afterwards used to tell about a
grove beneath the “Strait of Pharo,” how the tides wash first one way
and then the other through the branches of the trees, and how he had
seen submarine mountains, valleys, fields and woods, and trees with
acorns on them. Gervase adds that our faith in the truth of this story
may be increased by noting the fact that acorns are often washed ashore
along the neighboring coasts. Nicholas also used to occupy himself by
warning ships of the approach of storms and showing sailors how to calm
the waters with oil. At a later period the legend became current[900] of
a man named “Piscis” or “The Fish” (possibly this should be substituted
for the “Pappas” of Gervase) who was accustomed to swim under the Strait
of Messina, having been sent there in the first place to rescue a
chalice cast into the sea by King Roger.
Alexander the Great, according to one version of the Romance of his
adventures, also made a visit to the sea floor.[901] After he had
crossed a desert infested with ferocious beasts, he called his
companions together and complained that, in view of the fact that he had
conquered the greater part of the world, he knew enough about the
inhabitants of the land and now wanted to learn something of the
inhabitants of the sea. He then proceeded to descend in a glass cask to
the bottom of the deeps; there, among other things, he noted that the
large fish eat the small ones, an observation whose novelty hardly seems
to have justified the effort expended to make it.
_THE WATERS OF THE LANDS_
Let us turn now to the waters of the lands—ground water, sources (wells,
springs, fountains), rivers, and finally lakes.
GROUND WATER
In our period the existence of water in various forms underneath the
surface of the land was well understood. Bernard Sylvester says:[902] “A
watery humor is diffused all through the lap of the land and makes
streams and rivers, swamps and lakes.” William of Conches
attributed[903] the origin of the water in springs and wells to (1)
underground streams, or, as he called them, “cataracts,” which pass
through wells en route from one part of the earth to another, and (2)
the sweat of the earth (_sudor terrae_), or minute particles of water
percolating through small holes in the earth much as human sweat
percolates through the pores of the body. William maintained that the
existence of underground watercourses as a source of well water was
proved by the fact that wells near rivers are constantly full and that
whatever happens to the water of a well in a given district is likely to
happen to the water of all the other wells in the vicinity, showing that
there must be some intercommunication between them. That springs and
wells were constantly replenished in dry times was proof to William—as
to modern geographers—of the existence of the sweat of the earth, or
what we now call “ground water,” which permeates the interstices in
rocks, gravel, and sand alike. It is possible, however, that William
believed that the _sudor terrae_ was actually generated by the earth.
This was undoubtedly the opinion of Adelard of Bath, who discusses the
subject in terms very similar to those of William.[904]
THE SEA AS THE SOURCE OF THE WATERS OF THE LAND
Most of this subterranean water, as we have already seen, was supposed
during the Middle Ages to come from the sea, whence it made its way
inland either through the atmosphere in the form of rain or directly
through the land. We need cite but two texts to show how firmly this
idea was rooted in the medieval mind. One is from a sermon of Bernard of
Clairvaux, the other from a questionnaire prepared by the Emperor
Frederick II. It would perhaps be hard to find two men who stood at more
diametrically opposite intellectual poles, and yet both, in this case,
shared the same conviction.
Bernard, characteristically, treated the matter symbolically. “The sea,”
he said, “is the source of fountains and rivers; the Lord Jesus Christ
is the source of every kind of virtue and knowledge.... What? Are not
pure purposes, just judgments, holy aspirations, one and all streams
from that same source? If all waters seek incessantly to return to the
sea, making their way thither sometimes by hidden and subterranean
channels, so that they may go forth from it again in continual and
untiring circuit, becoming visible once more to man and available for
his service, why are not those spiritual streams rendered back
constantly and without reserve to their legitimate source, that they may
not cease to water the fields of our hearts? Let the rivers of divers
graces return from whence they came, that they may flow forth anew. Let
the heavenly shower rise again to its heavenly source that it may be
poured anew and still more plentifully upon the earth” (Eales’s
translation).[905]
Frederick II propounded to Michael Scot a list of questions on matters
of cosmology and physical geography. Regarding most of these matters the
Emperor was in doubt and perplexity, but concerning the waters of land
and sea he was sure. “For we greatly wonder at these things,” he said,
“knowing already that all waters come from the sea and passing through
divers lands and cavities return to the sea, which is the bed and
receptacle of all running waters” (Haskins’ translation).[906]
A most elaborate discussion of the qualities of the waters of the lands
is found in the _Causae et curae_ of Hildegard of Bingen.[907] Hildegard
likewise assumed that the water of wells, springs, and rivers is derived
from the ocean which surrounds the earth.[908] She also believed that
the nature of the water varies widely in different parts of the ocean
and consequently that the quality of the water of the land depends on
the part of the ocean from which it comes. Furthermore, she maintained
that some of the waters of the sea do not lose their salinity in passing
through the land but that other waters are rendered fresh before they
appear upon the earth’s surface. Upon the basis of these assumptions
Hildegard proceeded to analyze the qualities, sanitary, medicinal, and
gastronomic, of waters both fresh and salt according to their derivation
from the four cardinal points and from the northeast and northwest. Her
analysis was meant as a practical guide for those who wished to use
water for drinking and bathing with a minimum risk of disease, though
she fails to explain how one is to determine the ultimate source of a
specific spring, well, or river. Without undertaking a detailed
examination of Hildegard’s argument, we may note that, unlike Giraldus
Cambrensis, who regarded the East as the fountain of poisons, she
believed that the waters of the Orient were the purest and most
healthful of all. On the other hand, she held that the putrid and
corrupt elements of the earth were concentrated in the Western Sea and
that waters coming from that quarter were very dangerous unless
boiled.[909] The Southern Sea harbored an immense quantity of venomous
worms and small animals, and consequently waters from it were not good
for cooking or drinking. As we shall see in the next chapter,[910]
Giraldus Cambrensis’ discussion of the different qualities of the East
and West was probably based in some measure on observation. The same can
hardly be said of Hildegard’s theories. We cannot but feel that they
were the offspring of an unusually ingenious imagination, though the
prophetic abbess undoubtedly attributed them to divine inspiration.
Hildegard went on to assert that swamp waters are dangerous from
whatever part of the earth they come, since they contain vile and
noxious damp elements of the ground and the poisonous spume of worms.
Such waters should not be used unboiled except for washing. Well and
spring waters which flow from swamps are equally bad, though as a
general rule all waters arising from an unsanitary source become purer
the farther they flow. Water from deep wells is usually better and
smoother (_suavior_) for cooking, drinking, and other uses of man than
the water of flowing springs; the latter, in turn, is better than river
water, which should be avoided because of the impurities it receives
from the air. The water of small, clear, pure rills is excellent for
both men and cattle.
EFFECT OF LAND ON WATERS WHICH SPRING FROM IT
The land itself might produce varying effects on the water within it,
and thus on the wells and fountains which spring from it. In summer,
William of Conches tells us,[911] the pores of the earth are open, and
the warm vapor (_fumus_) contained therein can escape. Consequently the
heat of the earth is loosed, and the springs and wells are cooler than
in winter, when the cold constricts the earth’s pores and keeps the heat
in. It is very easy to understand what gave rise to such a theory when
we consider the fact that water always preserves a more uniform
temperature than the surrounding air. Hot and putrid springs, the _De
imagine mundi_ tells us,[912] are caused by the ground water coming into
contact with subterranean caves full of sulphur that is sometimes
ignited by the winds. In some places serpents, by poisoning the earth
and the ground water which passes through it, indirectly cause the water
sources of a region to become noxious.[913] Michael Scot, in a somewhat
repetitious and not wholly clear passage, explained in effect that the
hot and boiling springs of Italy and Sicily are produced by waters
arising out of subterranean cavities where the native heat of the
interior of the earth in combination with the winds produces a violent
combustion of sulphur and “white-hot rocks” (_petre calidissime_).[914]
MIRACULOUS WELLS AND SPRINGS; GEYSERS
Wells and springs, like lakes, seem to have appealed to the imagination
of men at all times, and the description of their peculiarities occupied
disproportionate space in medieval books of marvels. Giraldus Cambrensis
mentions wells with petrifying properties in Ulster, Norway, Britain,
and Cappadocia;[915] and Saxo Grammaticus expresses great wonder at a
spring in Iceland the exhalation or foam of which is capable of turning
the softest substances almost instantaneously into the hardest
stone.[916] Gervase of Tilbury describes a salt well in the diocese of
Worcester.[917] Though these are reasonable enough, it is a little more
difficult to explain Giraldus’ belief in wells which ebb and flow like
the tides,[918] especially when he insists that some of them are
situated far from the sea.
Giraldus describes an absolutely miraculous spring in the province of
Munster in Ireland.[919] When touched or even looked at by a man, this
spring will proceed to inundate the entire province with rain. The rain
does not stop until a priest, virgin from birth and especially deputed
for the purpose, celebrates mass in a chapel not far away and, having
blessed the waters, conciliates the spring by sprinkling into it the
milk of a one-colored cow. Giraldus remarked parenthetically that this
was a barbaric ceremony and quite lacking in reason. Gervase of Tilbury
tells of a lake in Great Britain which would produce a storm when
certain words were chanted over it and of a fountain in the Kingdom of
Arles which would cause rain if a stick or stone were thrown into
it.[920] These tales, indeed, are but examples of a widespread belief
among primitive and ignorant folk that man can attain the secret of the
magical control of the elements. Sir James G. Frazer cites them with
similar examples from other peoples and ages as illustrations of the
doctrine that a “way of constraining the rain-god is to disturb him in
his haunts. This seems to be the reason why rain is supposed to follow
the troubling of a sacred spring.”[921]
In treating the water element in his _De naturis rerum_, Alexander
Neckam rushes over the problems of the four rivers of Paradise and of
why the sea is salt to come to a discussion of springs,[922] about which
he relates many marvels, appending to each a little moral lesson. For
example, he tells of two founts in Italy, one of which turns the
feathers of white birds black, and the other the feathers of black birds
white. He suggests the analogy of the former to contemporary worldly
knowledge that darkens minds glowing in the brightness of innocence; and
of the latter to true wisdom that renders serene minds obscured by the
shades of vice.[923] Then he goes on to discourse about springs that
rise when some one throws a red cloth into them; a spring that boils up
with much noise, as if in annoyance, when men talk near it; a spring
that gives flame to an unburnt torch and puts out a lighted one; and a
spring whose water, when thrown upon a certain rock in its neighborhood,
causes a storm of wind, rain, and hail to arise. These are but a few of
many remarkable sources that Neckam describes and places in various
parts of the world, drawing on Solinus, Isidore, and the mass of
medieval pseudo-science that flourished in all countries.
More convincing is Saxo Grammaticus’ circumstantial account of certain
water holes in Iceland. In these the water sometimes wells up in
abundance and is thrown high into the air in a shower of drops. At other
times the flow is quiescent, and the water seems to be sucked into the
holes deep in the earth where it scarce may be seen. This description is
obviously based on reports Saxo had received from eyewitnesses of the
geysers of Iceland.[924]
THE FOUNTAIN OF YOUTH
The most remarkable and most sought-for of sources has always been the
Fountain of Youth. In the first letter of Prester John we find the
description[925] of a grove at the foot of Mount Olympus, not far from
Paradise, in Central Asia. In this grove there is a spring that wafts
forth odors of all kinds, varying from hour to hour, by day and by
night. Its waters give eternal youth to any one who bathes therein,
restoring him to the bodily strength and vigor that he possessed at the
age of thirty-two. Closely parallel to this account, though probably not
derived from it, is a description in the Romance of Alexander[926] of a
fountain that receives its waters from the Euphrates, one of the four
rivers of Paradise, and which four times daily has the power of
rejuvenation. Two old men who jumped in emerged looking exactly as if
they were thirty years old. Akin to the Fountain of Youth, but less
powerful in its action, is a spring described by Gervase[927] in
Staffordshire, England, to which he attributed the ability of restoring
energy to men when weary. But this is true of any fresh mountain pool.
RIVERS
As to the source of rivers, we need add nothing to what has already been
said about the “congregation of waters” (_congregatio aquae_) and about
springs and fountains. It was commonly thought in medieval and classical
times that two or more rivers may rise from one source and flow off in
diverse directions. The most striking example of this was furnished by
the Scriptural four rivers of Paradise, which, though rising from one
stream, were believed to find their way to at least three different
seas. In commenting on the rivers of Paradise, Gervase of Tilbury
expressly asserts[928] that not only is it possible for more than one
stream to rise from the same headwaters but that the same rivers may
again mingle and again separate their waters. Giraldus Cambrensis
describes[929] how the Shannon of Ireland rises in a lake between
Connaught and Munster and thence divides into two branches flowing in
opposite ways, one southward to the “Sea of Brandan,” the other
northward into the Northern Ocean. It is true that in regions of
imperfect drainage development, like Ireland, northern North America,
and parts of the Amazon Valley, two small streams occasionally do spring
from a single source. On the other hand, it is entirely contrary to the
laws of hydrography that two or more full-grown rivers should either
leave a lake and depart across country in different directions or,
except in the case of deltas, owe their origin to the separation of the
waters of a single large stream. Classical and medieval geographers,
however, were not acquainted with this law, and the words of the Bible
justified the writers of geographical books, even down to as late a date
as the eighteenth century, in making broad rivers divide into separate
branches and wander at random over the country.
Giraldus Cambrensis noted several other peculiarities of rivers.[930]
For example, he remarked that the stream at Wicklow which flows across
the harbor (we may presume in a channel through mud flats) is brackish
at ebb tide; a similar river at Arklow is fresh.[931] Tide water, he
said, does not mingle with the River Conway in North Wales.[932]
Elsewhere he observed that the term _aber_ in Welsh is applied to all
those places where one stream flows into another.[933] The River Dee is
not affected by rains, but the winds make it rise.[934] It changes its
bed every year, and, as its course forms the boundary between England
and Wales, these changes are interpreted as omens foretelling whether
the English or the Welsh are going to be the more successful in their
combats with each other during the succeeding year.[935]
THE NILE FLOOD
In his consideration of the problem of the flood of the Nile, Abelard
gives a curious example of the symbolic interpretation of scriptural and
geographic matters which was also characteristic of the writings of
Bernard of Clairvaux.[936] Isidore had followed earlier classical
authorities in describing the flood as due to the building up, by the
etesian winds, of sand bars at the mouth of the river during the
winter.[937] Abelard, from Bede’s rendering of Isidore’s text,[938]
adopted the same theory in his discussion of the Nile in the _Expositio
in hexaemeron_.[939] He also discussed the Nile flood in a sermon on the
text, “And the Lord, the God of hosts, is He who toucheth the earth, and
it shall melt: and all that dwell therein shall mourn: and it shall rise
up as a river and shall run down as the river of Egypt” (Amos ix, 5). In
the sermon[940] he compared the rising of the Lord at the resurrection
to the Nile: as the river fructifies the land, so the Lord strengthened
the despairing hearts of his disciples. Abelard then quoted the passage
from Bede just mentioned, and proceeded to interpret it as follows: The
Nile coming down from Paradise is like unto the wisdom of God descending
from above to give us to drink as from a fountain. Egypt is like unto
the carnal darkness of this world. Its river enters the sea through
seven mouths, which are obstructed when the wind blows and causes the
backing up of the waters that can find no outlet. Thus, after the
resurrection of the Lord but before the sevenfold grace of his spirit
could find its way out into the broad sea of the nations, it was impeded
as were the waters of the Nile. In other words, the apostles, through
fear of the Jews, were held in Judea blinded, as it were, and for some
time were not permitted to go forth as if from Egypt and through their
preaching to bring about a rebirth of mankind. What does the wind
represent, Abelard asks, if not the temptation of the devil? And what
the sand, if not those men who at the turning of the ages wavered this
way and that, held fast by earthly desires and temptations? [941]
It is hardly necessary to point out the contrast between this sort of
geographical speculation and that of William of Conches. Better perhaps
than any other text with which the writer is familiar, these ideas of
Abelard illustrate that absorption, so often characteristic of medieval
thought, of scientific and geographical interests into those of
theology.
LAKES
Abundance of lakes is characteristic of glaciated countries like New
England, Switzerland, Scotland, Sweden, Wales, and Ireland. Giraldus
Cambrensis was impressed by the number of lakes in Ireland, where, he
says,[942] they are more numerous than in any other part of the world.
Giraldus and Gervase of Tilbury describe many lacustrine marvels.
In tracing the history of Ireland, Giraldus says [943] that about three
hundred years after the Deluge four ponds suddenly broke forth from the
bowels of the earth and that this was repeated at the time of the third
colonization of Ireland under Neimhith.[944] Two ponds in Wales [945]
were said to have burst their bounds and overflowed the neighborhood on
the night of the death of Henry I. Before a great war, during which a
province of central Wales was ravaged, a certain lake turned green, and
old men described a similar portent just before the devastation of Wales
by “Hoel, son of Moreduc” (Howel, son of Meredith).[946] The Lake of
Brecknock in Wales appears sometimes a greenish color and sometimes
ruddy as if penetrated by veins of blood.[947] Perhaps Giraldus was
reminded of this by the mud-streaked appearance of mountain tarns after
a rain, but it is less easy to explain the buildings, pastures, gardens,
and orchards which he declares were occasionally visible beneath the
surface. On the other hand, all who are familiar with inland waters in
cold latitudes know the booming sounds they emit when frozen, which
Giraldus compares to the moaning of a large herd of animals. These
noises, he said, were caused by the sudden outrush of air imprisoned
beneath the ice. At the top of Mount Snowdon, according to Giraldus,
there are two lakes, one containing a floating island blown by the
winds.[948] The most interesting lake with which Giraldus deals,
however, is Lough Neagh in Ireland. This, he said,[949] lies in Ulster
and is of remarkable size, thirty miles by fifteen. Though the relative
proportions are right, the actual size is exaggerated, the dimensions
being fifteen English miles long by from five to eight broad. The origin
of the lake he attributed to an inundation that came as a punishment for
the unnatural crimes of the natives of the region. This led him to a
comparison of the story of Lough Neagh with the Biblical history of the
destruction of the Pentapolis and the origins of the Dead Sea.
The Dead Sea has always exerted a potent fascination over the minds of
men. The uncanny natural features of its basin, and the terrible story
associated with them, have been objects of curiosity from the very
earliest times. Gervase of Tilbury goes into some detail on the
subject.[950] The five cities, he says, were submerged, on account of
the sins of their inhabitants, in a salt and sterile lake called the
Dead Sea, where neither bird nor fish can live. The sea is open to no
ship; nay, it even rises over everything not impregnated with bitumen,
probably because of the living men within it. If any one by any means
immerses a living creature in it, the living being immediately leaps
out.[951] A burning torch will float on the lake, an extinct one will
sink. There was certainly an infernal quality about the Dead Sea, and it
was even supposed that beneath its waters there was an entrance into
Hell.
Gervase tells of the discovery of another mouth of Hell near Pozzuoli in
southern Italy.[952] A bishop John of Pozzuoli was said to have
discovered a pond whose waters were opaque but would become clear and
translucent when oil was thrown upon them. Exploring about its shores
one day, the bishop heard the sounds of lamentation coming from beneath
the waters and, casting oil upon them, was horrified to behold, far down
in the depths, the gateway to the infernal regions! Elsewhere[953]
Gervase tells of a lake on the summit of Mount Cavagum (Canigou) in
Catalonia, inhabited by devils, who raise a storm when stones are thrown
in to disturb them.