Chapter VIII: 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.