The narrative of the Deluge contains two separate statements:

a) the Deluge ended on the first day of the second year (8:13a).
b) the Deluge ended on the 27th day of month II of the second year (8:14).

Critical commentators have not paid attention to the first statement, and fundamentalist commentators have tried to take the text at face value, denying that there is a contradiction.

The latter usually claim that the waters had withdrawn by the first day of the new year, but that it took a month and 26 days more for the earth to dry. Perhaps more reasonable are the fundamentalists who claim simply that Noah waited a month and 26 days before leaving the Ark. But this explanation is awkward. The most detailed and clear fundamentalist, Cassuto, states that on the first day of the second year Noah "verified that the water had withdrawn," and that on the 27th of the II month "the earth was now definitely dried up." He was trying to cover up the contradiction in the text by adding the adverb "definitely"; this implies that there were two kinds of drying up, one final and an earlier one that was not final.

The fact is that the two statements are irreconcilable. This is recognized by implication in the translation by E. Speiser in the Anchor Bible in order to give a coherent meaning to the narrative, he translates the text as reading that on the first day of the new year "the waters had begun to dry from the earth" -- but this is an unwarranted translation. The hand that added the end on the 27th of the II month, tried to reconcile the new statement with the older one, by describing the date of the first day of the year as the day in which "Noah removed the covering from the Ark." This sentence was placed before a sentence from the earlier statement which says: "And he saw that the earth was dry." The "covering" is an entity never mentioned before and which is difficult to explain in terms of the account of the construction of the Ark. It is amusing to notice how Cassuto tries to go around the difficulty: "Noah removed the covering from the Ark and verified, now that his sight could move freely in every direction, better than from the narrow opening of the window, that the water had withdrawn."

The ending on the first day of the second year is explained by the Midrash and the Talmud, a source of information that strangely has been neglected by modern fundamentalists. All modern fundamentalists, in order to give a coherent meaning to the text of Genesis, assume that the 40 days of rising water are a part of 150 days of rising water. From the Midrashim and the early rabbis quoted in the Talmud we learn that the way the two basic versions were reconciled in the synagogue was by assuming that the water rose for 40 + 150 days and that it ebbed for 150 + 40 days.^(104b)

Since the first version spoke of the flood coming in the form of rain for 40 days, and the second version spoke of the flood coming from above and from below for 150 days, this was explained by assuming that the first 40 days mankind was granted one more chance to repent. During 40 days rain dropped mercifully, so that it would have turned into a blessing if mankind had decided to repent; but at the end of the 40 days the fountains of the deep broke loose and the flood became utterly devastating.

The construction contrived by the fourth hand was ingenious. Ingenuity was further manifested in conceiving a system of figures such that the arithmetic of the Deluge story would fit both pre-exilic lineal standards and post-exilic ones. This difficult result was achieved by shifting back and forth between solar and lunar calendars. This combination was justified by the circumstance that the third hand had computed by a solar calendar, whereas the two earlier versions were based on a lunar calendar.

If the water rose for 190 days and the earth was dry on the first day of the new year, this means that the period of ebb was 118 days (counting by a lunar year of 354 days, as the Midrash and the Talmud do). Now, 190 x 118 = 22,420. This means that the date which ends the Deluge on the first day of the new year was introduced after commentators had tried to reconcile the duration of 40 days and the duration of 150 days by combining them together. In order to arrive at a result similar to that obtained by the multiplication based on 40 and on the multiplication based on 150, there was introduced a multiplication 190 x 118 by which the Deluge had to end on the first day of the new year.

It is possible to suggest as a supposition how the mentioned commentators concluded that a period of 40 + 150 = 190 days of rising water was the correct solution: At the time the story of the Deluge was so expounded the lineal standard used by the Jews was the Babylonian-Egyptian royal cubit equal to 5/6 Roman cubits. According to this standard the radius of the Earth would be 12,000,000 cubits. The height of the water of the Deluge would be reckoned as 18,750 royal cubits on the basis of the earlier calculation of 22,500 cubits (6/5 18,750 = 22,500). Hence, they could conclude that the radius of the earth is 40 x 300 x 1000 cubits = 12,000,000 cubits and the height of the water was about 190 x 100 cubits.

Those who introduced this calculation started with the interpretation that the period of rising water was 40 + 150 = 190 days, but they were not satisfied with the solution according to which the period of ebbing water was 118 days. They felt that the period of flow and ebb should be equal in length, but they found that a Deluge of 190 + 190 = 380 days could not be fitted into any mathematical scheme.

The length of the Deluge should have been 190 + 190 = 380 days, but it was reduced to 375 days by assuming that when Genesis speaks of 150 days it means 5 lunar months. Five lunar months are 5 x 29.5 = 147.5 days, so that the total duration of the Deluge becomes: 40 + 147.5 + 147.5 + 40 = 375 days

The height of the water was explained by assuming that the water rose 100 cubits a day for 187.5 days and ebbed 100 cubits a day for 187.5 days. According to this interpretation the staying in the Ark lasted 187.5 + 187.5 = 375 days. Therefore the fourth hand added verse 8:14 which states that the earth was dry on the 27th of month II of the second year, that is, 365 days (a solar year) + 10 days after the beginning of the Deluge on the 17th of month II of the first year.

The figure of 187.5 days was explained by assuming that the references of Genesis to 150 days were a way of referring to five months, lunar months, which are 147 days. According to Midrashim, the first 40 days of the Deluge extended from the 17th of Heshvan to the 27th of Kislev, and were continued to a period of flood lasting through Tebeoth, Shebat, Addar, Nissan and Iyyar, so that the water began to ebb on the 1st of Sivvan. The total is 187 days.

There remained half a day to be accounted for. This was accounted for by considering the difference between solar and lunar computations. According to the original version the water came at the end of the 17th day of month II, towards evening, that is, at the beginning of the 18th day. When one computed by the moon, the day began in the evening, whereas when one computed by the sun, the day began in the morning. According to our way of computing, which is based on a solar calendar, the Deluge began on the evening of the 17th day. To make it absolutely clear that a solar calculation was being used in this instance, the fourth hand added, before the original verse 7:13 -- which implied that the water came at the end of the 17th day, lunar reckoning -- verse 7:12 which states that it came during the 17th day. This means that there was water coming through the second half of the 17th day, solar computation. For this reason the following references to a period of 40 days of rain were emended to read "forty days and forty nights." As a result the period of 40 days became 40½ days -- 41 nights and 40 days.

If the radius of the Earth is 14,400,000 cubits, it would have to be calculated as:
375 x 384 x 100 = 14,400,000

Possibly they introduced into the calculation the perfect figure of 380, reckoning:
375 x 380 x 100 = 14,250,000

This figure is quite close to 14,323,945 cubits which is the value of the radius obtained by computing by the exact value of p or close to 14,318,181 cubits obtained by computing p = 3 1/7.

They may have started with an effort to compute the radius as:
380 x 380 x 100 = 14,440,000 cubits

The radius of the Earth could be expressed as something between
380 x 380 x 100 = 14,440,000
375 x 375 x 100 = 14,062,500

But the calculation aims at explaining the Deluge in terms of the post-Exilic lineal unit, the Babylonian-Egyptian royal cubit, which was the standard familiar to the congregation attending the synagogues. According to this standard we have:

Circumference of Earth:	75,000,000 cubits
Radius of Earth:	12,000,000 cubits
Height of water:	18,750 cubits

Two of these figures could be expressed by dividing the period of 375 days into two periods of 187.5 days:
Circumference of Earth:
187.5 x 40 x 10,000 = 75,000,000 cubits
Height of water:
187.5 x 100 = 18,750 cubits
Radius of the Earth:
187.5 x 40 x 40 x 40 = 12,000,000 cubits

The radius of the Earth could also be expressed by referring to the starting figures of the calculation:
40 x 300 x 1000 = 12,000,000

It is easy to see how one arrived at this interpretation. Reckoning by pre-exilic cubits, Roman cubits, one could calculate the height of the flood as:
375 x 60 = 22,500 cubits
The circumference of the Earth can be computed as:
375 x 40 x 40 x 150 = 90,000,000 cubits

In conclusion, the modern interpreters who have tried to reconcile the elements of the text by assuming a combination of solar and lunar computations are on the right track. Those modern interpreters who understand that the references to 150 days mean 5 lunar months amounting to 147 days, are correct in terms of the last modification of the text of Genesis.

Alexander Heidel applied himself to the problem of the contradictions in the accounts of the duration of the Deluge and tried to remove them by presenting the following argument, which I quote in full because it is a fine piece of scholarship.⁽¹⁰⁵⁾

Days 1-150 Water raised or maintained its level for 150 days. For the first 40 days it poured torrentially from the sky; later, for an indefinite period, the rain continued more moderately, but the subterranean springs burst forth because of the downpour.

VII.17

151 Water began to decrease and the Ark grounded on the mountains of Ararat -- interval of 74 days -- 225 The tops of the mountains became visible.

XI

-- interval of 40 days -- 265 Noah opened the window 266 Noah sends out the first bird -- interval of 7 days -- 273 Noah sends out the second bird -- interval of 7 days -- 280 Noah sends out the third bird -- interval of 7 days -- 287 Noah sends out the fourth bird

XII.3

-- interval of 28 days -- 315 The surface was dried up but the ground was not yet fully dry. Noah removed the covering of the Ark.

[year II] I.1

-- interval of 56 days -- 371 The earth was again dry and Noah left the Ark.

II.27

If we had access to the complete text of the supposed documents denominated J and P (assuming for the sake of argument that such documents ever existed) we might see at once that there were no discrepancies at all between the two. But even without such access, it has been demonstrated repeatedly that the alleged contradictions in the Genesis narrative are capable of a simple and reasonable solution if the story is left as we find it in the Hebrew text.

I accept Heidel's interpretation with the following reservations:

a) His argument does not disprove that there are included in the narrative passages that indicate a duration of 40 days and a duration of 150 days. It indicates only that an editor tried to remove contradictions by including the period of 40 days and the period of 150 within the framework of a longer span of time.

b) The duration of the Deluge according to the third version is not 371 days, as Heidel concludes, but 376 days. The calculation which he reconstructs is based on the Egyptian calendar of 12 months of 30 days each. But in the Egyptian calendar the last month of the year was followed by a supplementary period of five days (epagomenal days), so that the year consisted of 365 days. If we add the epagomenal days, as we must, the Deluge lasted 376 days.

The explanation of the figure of 376 days is simple. According to the Hebrew system of units the radius of the Earth is 3760 x 3760 cubits = 14,137,600 cubits = 6,275,594 meters.

By stating that the Deluge lasted 40 or 150 days, Genesis intended to indicate that the radius of the Earth was increased by about 22,342 cubits.

As a first approach I may point out that 40 x 40 x 14 cubits is 22,400 cubits, and that 150 x 150 cubits is 22,500 cubits. Calculating exactly the height of the Deluge was 22,460 cubits. 22,475 cubits = 99,770.61 meters.

So, everything can be tied together organically, everything can be explained with absolute clarity and, most important of all, in a simple way. The chronological data, far from proving that there were two sources of the story, turn out to constitute an argument in favor of a single source.

Concluding this argument, which by now is a long one, we can realize that in the story of the Deluge there are neither contradictions nor repetitions such as would lead us to consider it composed of elements from two earlier stories. We can realize, on the contrary, that the story presents evident signs of a harmonious unity both in conception and in presentation.

Month	Day	Days Passed	Intervals
II	17	46
		150	Period of high water. Includes 40 days of rainpour and a period of slowly decreasing water.
VII	17	226	Ark rests on mountains in Ararat
X	1	270	Tops of mountains visible 40 days of further decrease
XI	10	310	Noah releases the raven
XI	17	317	First flight of the dove
XI	24	324	Second flight of the dove
XII	1	331	Third flight of the dove
Second year:
I	1	365	Noah removes the cover Water has withdrawn
II	27	411	Earth definitely dry Noah leaves the Ark

104b. Passages of the Midrash and opinions of rabbis quoted in the Talmud that speak of two periods of 190 days are listed by Abraham Levene (p. 187).
105. A. Heidel, The Gilgamesh Epic and Old Testament Parallels (1946).