29. The harmony of the Moon and the sea
THE RECKONING OF TIME
also presages a receding current in channels, or even a re£ux of the sandbanks which are found hard by the ocean; they say that these, following the phases of the Moon, are violently shifted to regions nearby. Currents in both directions are also wont to change their usual gentle £ow for the remainder of this period; for when the Moon is new they cannot lie still, but rage with ¢erce turmoil until the Moon appears again to bestow calm upon the agitated waves.252
29. THE HARMONY OF THE MOON AND THE SEA
But more marvellous than anything else is the great fellowship that exists between the ocean and the course of the Moon.253 For at [the Moon's] every rising and setting, [the ocean] sends forth the strength of his ardour, which the Greeks call ''rheuma'',254 to cover the coasts far and wide; and when it retreats, it lays them bare. The sweet streams of the rivers it abundantly mingles together and covers over with salty waves.
When the Moon passes on, [the ocean] retreats and restores the rivers to their natural sweetness and level, without delay. It is as if [the ocean] were dragged forwards against its will by certain exhalations of the 252 Basil, Hexaemeron 6.10^11. The translation is not Eustathius', and Jones' apparatus suggests that it may have been by Bede. However, the consensus of most recent scholarship on the knowledge of Greek in 8th-century England, and Bede's in particular, is that this is not a very likely possibility. K.M. Lynch, in ''The Venerable Bede's Knowledge of Greek'', Traditio 39 (1983):432^439, argues that Bede's knowledge of Greek increased throughout his life. In his early commentary on the Acts of the Apostles, he was dependent on Greek/Latin interlinear texts and frequently transcribed their errors. In the Retractatio, he corrected these, and demonstrated other signs of deeper knowledge of biblical Greek.
But whether this amounted to the ability to translate texts independently is another matter. Even the students of Theodore and Hadrian seem to have received no instruction in Greek grammar, nor could they actually read Greek: see Michael Lapidge, ''The Study of Greek at the School of Canterbury in the Seventh Century'', in The Sacred Nectar of the Greeks: The Study of Greek in the West in the Early Middle Ages, ed. M.W. Herren, King's
CollegeLondonMedievalStudies 2 (1992):164^169. See also A.C. Dionisotti, ''Bede, Grammars and Greek'', Revue be¤ ne¤ dictine 92 (1982):111^141; J. Gribomont, ''Saint Be' de et ses dictionnaires grecs'', Revue be¤ ne¤ dictine 89 (1979):271^280; Mary Catherine Bodden, ''The Preservation and Transmission of Greek in Early England'', in Sources of Anglo-Saxon
Culture, ed. Paul E. Szarmach, Studies in Medieval Culture 20 (Kalamazoo: Medieval Institute Publications, 1986):53^63.
253 Cf. ps.-Isidore, Liber de ordine creaturarum 9.4 (148.28^30); Virgilius Maro
Grammaticus, Epitoma 4 (17.6^7).
254 Vegetius 4.42 (161.4); by contrast, Isidore uses the word rheuma only in its medical sense of ''morbid discharge'': Etym. 4.7.11.
TRANSLATION
Moon, and when her power ceases, it is poured back again into his proper measure.255
For as we taught above,256 the Moon /367/ rises and sets each day 4 puncti later than it rose or set the previous day; likewise, both ocean tides, be they by day or by night, morning or evening, never cease to come and go each day at a time which is later by almost the same interval.
Now a punctus is one-¢fth of an hour, and ¢ve puncti make an hour.
Furthermore, because the Moon in two lunar months (that is, in 59 days) goes around the globe of the earth 57 times,257 therefore the ocean tide during this same period of time surges up to its maximum twice this number of times, that is, 114, and sinks back again to its bed the same number of times. For in the course of 29 days, the Moon lights up the con¢nes of Earth 28 times, and in the twelve hours which are added on to make up the fullness of the natural month, it circles half the globe of the Earth, so that, for example, /368/ the new Moon which emerged [from conjunction] last month above the Earth at noon, will this month meet up with the Sun to be kindled at midnight beneath the Earth. Through this length of time,the tides will come twice as often, and 57 times the high seas swell, breaking their barriers and once again retreat unto themselves.258
Because the Moon in half a month (that is, in 15 days and nights) circles about the Earth 14 times, and once besides around half the Earth, it happens that it is in the east at evening when it is full, while earlier it was in the west at evening when it was new. In this period of time, the sea ebbs and £ows 29 times. Just as the Moon in 15 days (as we said) is £ung back by its natural retardation towards the east from its position in the west at evening,259 [so that while it] occupies the east today at morning,
255 Ambrose, Hexaemeron 4.7.30 (136.3^5). Cf. Isidore, DNR 40.1 (307.8^11).
256 Ch. 17.
257 See n. 260 below.
258 Vergil, Georgics 2.479^480, ed. R.A.B. Mynors (Oxford: Clarendon Press, 1990):li.
259 The Moon moves across the sky in two ways. Each day, it rises in the east and sets in the west: from the medieval perspective, this is because it is borne about by the daily east-west rotation of the outermost heavenly sphere. But the Moon also progresses eastwards around the zodiac once each month. Bede imagines the Moon ''falling behind'' the daily rotation of the outermost heavenly sphere, so that it rises each day a little later. The Moon that rose and set with the Sun at conjunction, rises and sets 12 hours later, and half the sky away, when it is full.
THE RECKONING OF TIME
it will be in the west at morning 15 days from now, so also the ocean tide which now occurs at evening, will after 15 days be in the morning. On the other hand, the morning tide, impeded by this daily drag, will then rise at evening. And because the Moon in one year (that is, in 12 of its months, which makes 354 days) circles the globe of the Earth 12 fewer times (that is, 342 times), /369/ so the ocean tide within the same period washes up against the land and recoils 684 times.260
The sea re£ects the course of the Moon not only by sharing its comings and goings, but also by a certain augmenting and diminishing of its size, so that the tide recurs not only at a later time than it did yesterday, but also to a greater or lesser extent. When the tides are increasing, they are called malinae, and when they are decreasing, ledones.261 In alternating periods of seven or eight days, they divide up every month among themselves in their fourfold diversity of change.
Sometimes by equal shares both ¢ll up their course in 7ˆ~˜ days; sometimes they will arrive earlier or later, or be more or less strong than usual when they are pushed onwards or forced back by the winds, or by the pressure of some other phenomenon or natural force, with the result that sometimes their order is upset, and the malina tide claims more in this month, and less in the next. Hence both directions will begin now in the evening, now in the morning. Indeed, when an evening tide occurs at the full or new Moon, it will be a malina, and for the next seven days this same malina tide will be greater and stronger than the morning tide.
Similarly if a malina tide starts in the morning, the morning tide for days afterwards will cover /370/ the land with more sea. The evening tide, con¢ned to the boundaries laid down by the morning tide, refrains from extending its course further, although in some months both tides grow at utterly di¡erent rates.
The more the stronger tide covers the shore and lands and ¢lls up the 260 Bede imagines that the Moon every day ''runs ahead'' of the Sun by 4 puncti, or ˘~˙ of an hour (48 minutes), so that it can meet up with the Sun at conjunction 29ˆ~˜ days later
(cf. ch. 17). Over 354 days, this advance would amount to about 12 days (486354 = 16,992 minutes 7 60 = approximately 283 hours 7 24 = 11.8 days).The ''gain'' is therefore about 1 day each month. Hence, as Bede said earlier, the Moon circles the Earth 28 times each 29 days, 57 times each 59 days, etc. From a modern heliocentric perspective, we would say that the Earth rotates 29 times, but the retardation of the Moon means that it seems to circle our planet one less time.
261 These terms are usually translated as ''spring tide'' and ''neap tide'' respectively. For further discussion, see Commentary.
TRANSLATION
rivers and straits, the more it is wont to leave these same coastlines empty and bare as it recedes. So let him who is capable, see if what Philip says is true or no: There are those who claim and a⁄rm that an enormous outpouring of the ocean takes place in all the streams of every region and land at one and the same time.262 But we who live at various places along the coastline of the British Sea know that where the tide begins to run in one place, it will start to ebb at another at the same time. Hence it appears to some that the wave, while retreating from one place, is coming back somewhere else; then leaving behind the territory where it was, it swiftly seeks again the region where it ¢rst began. Therefore at a given time a greater malina deserts these shores in order to be able all the more to £ood other [shores] when it arrives there.
This can easily be grasped from the Moon's course. For example, positioned at about the winter sunrise or at the [summer] solstice sunset, the Moon at any given age, whether it be above the earth or beneath it, will pull at the tide here, but will repel it when she is positioned at winter sunset or summer solstice sunrise. But the Moon which signals the rise of the tide here, signals its retreat in other regions far from this quarter of the heavens. And there is more: those who live north of me on the same coastline usually receive and give back each tide sooner than I do, and those /371/ to the south much later. In every region, the Moon holds to whatever rule of fellowship with the sea it received in the beginning. Hence we have ascertained that the malina often begins about ¢ve days before the new or full Moon, and the ledones the same number of days before the half Moon. Near the two equinoxes, the tide rises higher than usual, and is much lower at the winter and summer solstices. The Moon always exerts less force when she is in the north and at her highest point away from the Earth263 than when she ventures into the south and treads closer. Natural reason [naturalis ratio] convinces us that the tides
£ow according to the pattern of the Moon's cycle of 19 years; hence the course of the sea returns to the beginning of its movements and to equal increments.264
262 Philippus Presbyter, Commentarii in librum Job 38 (PL 26.752C).
263 By ''Earth'', Bede means ''horizon''; cf. ch. 26.
264 Pliny, HN 2.99.215^216 (2.344). However, Pliny proposes an 8-year cycle for the tides. Bede accepted this model in The Nature of Things 39, but modi¢es it here.