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KRONOS Vol IV, No. 1
The Aubrey Holes Of Stonehenge
ALBAN WALL[*!* Image] Drawing 1. Stonehenge. Showing the principal elements of the structure.
What usually comes to mind at the mention of Stonehenge is a picture of huge stones standing and lying in general disarray on a green field somewhere in southern England. As I will try to show, although these megaliths did form a vital part of that ancient monument, by no means were they the only or most important element in the structure.
As is now generally assumed, Stonehenge was built in three separate phases. Each one of these phases was partially connected to, while it partially remained separate from, the one which preceded it, the latter two retaining, while also adding to, the basic features incorporated in the original. What time gaps existed between these construction stages has never certainly been determined. In this exposition I shall be dealing principally with those elements that are generally attributed to Phase I, which are as follows: (Drawing 1)
1) A circular dirt bank about 6 feet high, 300 feet in diameter (now almost completely eroded away), pierced in its northeastern sector by a broad, flat avenue that leads in a straight line away from the site.
2) A circle of 56 holes (called the Aubrey circle) immediately inside the bank, from which the dirt was originally removed to be replaced with a filling of chalk rubble.
3) An upright megalith called the Heel Stone (or Friar's Heel) stationed approximately 256 feet from the center of the circle, offset to left of center in the avenue and having an azimuth of 51.3° E of N. (The closeness of this azimuth value to the latitude of Stonehenge - 51.2° N - is probably more than just coincidence.)
The modern concensus of opinion concerning this ancient structure, when taken as a whole, is that it was probably a primitive observatory used to determine the point of sunrise on the first day of summer, to predict eclipses (relatively rare events), while it also served as a kind of "crude" calendar.(1) However, my studies show that, far from being merely a "crude" calendar or"primitive" observatory, the site actually constituted a sophisticated and effective device for keeping track of the days, weeks and months and for correlating these time increments to the visible movement of the sun along the horizon. Indeed, it formed a perfect solar calendar (among other things) far more exact and efficient than the calendric system in use at the present time.
Since the top of the circular dirt bank was about eye level, it would have served admirably as a uniform, artificial horizon by eliminating the irregularities of the natural one.
The circle of chalk-filled Aubrey holes stands out bold and clear against the background of the greensward, thus being easily visible. Since the holes are relatively uniformly spaced, about 16 feet center to center, they would have formed an effective azimuth circle by relating the position of the rising sun, as it came up over the bank, to the nearest hole the azimuth value of which would be known. In navigation, the bearing of a distant object is determined in just this manner. Since the Aubrey holes form a complete circle, azimuths of rising celestial bodies could have been observed and calculated at any point on the horizon.
When viewed from above, the Aubrey holes look strikingly like the marker points of a dial.
It has been established that the Heel Stone, as viewed from the center of the Aubrey Circle, quite closely marks the point of sunrise on the first day of summer, testimony to which "fact" being included in the official guide book of the monument.(2) Three months later, at the time of autumnal equinox, it is hole #6 that marks the point of sunrise. At winter solstice, having reached its most southerly declination, the sun will rise over hole #12. Hole #6 also marks the sunrise at the vernal equinox as the sun moves back northward while the Heel Stone will again mark the point of summer solstice, thus completing the yearly cycle.
This method of marking sunrises throughout the year, though certainly most highly developed at Stonehenge, was by no means unique to it. In Babylon, as early as 2000 B.C., the high priest observed sunrises by standing behind a stake and noting the position of the sun relative to the marker. By this means the priest-astronomers were able to pinpoint the solstices, equinoxes and other important religious as well as secular dates throughout the year.(3)
Similarly, at Uaxactun, Guatemala (328-1389 A.D.), the Mayan high priest would stand at dawn on a raised stone platform at the times of solstices and equinoxes and relate the sunrise to specific parts of the superstructure on a temple that stood directly to the east of him. (Drawing 3)(Drawing 4)[*!* Image] Drawing 2. The Stonehenge 13 Month Solar Calendar.
[*!* Image] Drawing 3. Maya Astronomical Observatory – Guatamala.
[*!* Image] Drawing 4. Natural Horizon Calendar using irregularities in the horizon as azimuth markers.
The Hopi Indians of the southwestern United States are known, even up till recent times, to have used a similar system wherein significant sunrises were related to specific features in the visible horizon. (Drawing 4)(5)
Marking sunrises along the horizon for calendric purposes was clearly then a primitive and natural way of keeping track of the seasons. What also appears to have been quite common among early time-keepers was the practice of fashioning their calendars in the round, thereby reflecting the cyclic aspect of time. That the ancients were conscious of the apparent circularity of time is evidenced by the Book of Exodus where we find the expression "at the revolution of the year."(6) The Hebrew word "tequwphah" - translated as "revolution" - actually means "to move in a circle, " "to go round." The same idea is also expressed in the Book of Second Chronicles by the phrase "in the revolution [tequwphah] of the year."(7)
Most striking of such ancient round devices was the pre-Christian Roman stone calendar in which a circle of 24 holes represented 24 half-months. (Drawing 5) Every 15 days a peg was advanced one hole. Thirty other holes, ranged along each side and appropriately numbered, were used to keep track of the date while an additional 7 holes at the top indicated the days of the week.(8)
But perhaps the most famous example of circularity in calendar designs is to be found in the Aztec calendar stone (ca. 1500 A.D.) now in the Mexican National History Museum. (Drawing 6)(9) Centuries earlier, the Maya had developed a long-range system for recording their history in thirteen 256-1/4 year increments, called katuns, which they also expressed in a circular form.(10)
The Aubrey hole circle at Stonehenge, used as a day-counter, accords well with this ancient practice of fashioning calendars in the round.
Having established comparisons to show that the concept of the Aubrey circle as a solar calendar is not without parallel, I will now describe how that ancient monument combines the horizon-marking and circular-dial system into a simple yet extremely accurate timekeeping mechanism.
The Aubrey circle consists of 56 holes. They are not all evenly spaced, only relatively so. It is my contention that each hole represents a half-day in the same manner that, in the Roman calendar stone, each stone represents a half-month. Thus it will be seen that the Aubrey circle consists of 28 days, one circuit of which constitutes a month. A quadrant of the circle contains seven days and the 28-day month will therefore consist of exactly 4 weeks of 7 days each.[*!* Image] Drawing 5. Ancient Roman Stone Calendar.
[*!* Image] Drawing 6. Ancient Aztec Circular Stone Calendar.
The arc of the horizon over which sunrises occur at Stonehenge, from hole #56 to hole #12 and back to hole #56, delineates the seasons in the manner indicated in Drawing 2. The value of this arc for the latitude of Stonehenge, calculated by using the sun's maximum declination converted to amplitude (the angular distance of a body on the horizon north or south of the equator), with corrections for refraction, dip, and parallax, was found to be nearly equal in angular distance to 12 hole-spaces - abut 78°.
A criticism that has been levelled against certain other investigators of Stonehenge is that many of their supposed celestial alignments are asymmetric - that is, they are calculated from a variety of foresights over a variety of back-sights in what has been called the "shot-gun method." By contrast, in my presentation all alignments and observations are calculated from a single point, the geometric center of the circle.
The Aubrey circle solar calendar then operates as follows:
On the first day of summer the sun rises close over the Heel Stone. At this time a movable marker is placed on hole #56. For the next six months sunrise will occur each day a little further to the south. When the sun rises over hole #6, which marks the equator and the autumnal equinox, the marker will have moved 93 days, or double hole-spaces (3 times around the complete circle plus 18 holes) and be at hole #18.
When the sun reaches hole #12, which marks the winter solstice, the marker will have moved 6-1/2 times (182 days) around the circle and be at hole #28. This is the half-year point. At this time the sun actually sets behind hole #28, where the marker sits, and the coordination of sun and marker at this point constitutes a check on the synchronization of the two moving elements.
When the rising sun returns to hole #6, which also marks the vernal equinox, the marker will have moved 271 days (9 turns of the circle plus 38 hole-spaces) and be at hole #38.
When the sun has moved back to within 1-1/4 days of the Heel Stone, the marker will be back to hole #56, having completed 13 circuits of the circle (13 x 28 double hole-spaces = 364 days). The marker is then left at hole #56 for one extra day of intercalation to bring the number of days up to 365. On the next day the sun should again rise close over the Heel Stone. The cycle is then repeated for another year. The 1/4 day remaining is left to accumulate for 4 years at which time another day is intercalated as is done for leap year. Weeks are ticked off each time the marker reaches holes #14, 28, 42 and 56. Since these 4 holes divide the circle into quadrants, and since the marker will move around the circle 13 times in the course of a year, we can see how the ancients calculated the 52-week year (4x 13).
It will be noted that each week, each month, each quarter and each year always begin on the same day of the week, and that each particular date will always fall on the same named day of the week - that is, the 1st will always fall on a Sunday, the 2nd on a Monday, and so on. This arrangement is, in fact, identical to the 13-month (of 28 days each) formula commonly referred to as the Comte Calendar (after the French philosopher who proposed such a scheme for world adoption in 1849).(11)
Critics might ask: Is there any evidence that the ancient Britons ever used a 13-month calendar? To which I answer: Not any more than there is any evidence that they ever used a 16-month calendar. Yet Thom, basing his calculations on the collective declinations of a multitude of megalithic sites, arrived at just such a conclusion.(12) If Thom's "calendar, " scattered as it is all the way from Cumberland to the outer Hebrides, can be accepted as valid then so should the one delineated above. In not one single locality that Thom mentions can his 16-month calendar have been put to a practical use as such. The 13-month calendar described above can. The elements of Thom's 16-month calendar are scattered over a wide terrain; those of the 13 month scheme are totally inherent in the Aubrey Circle alone. Also, while a 16-month calendar seems to have been unknown anywhere else in the world, "a year of 13 months is reckoned by quite as many peoples as reckon 12 months."(13)
The equinox and solstice points could also have been marked for convenience along the Aubrey Circle. As a matter of fact, it will be noted that two stones, #92 and #93, are set close to Aubrey holes #18 and #38 (see Drawing 1). These holes, it will be recalled, mark the positions where the day marker rests on the first day of autumn and the first day of spring respectively. The four seasons were therefore delineated along the Aubrey Circle by the stones set near holes # 18 and #38, by the Heel Stone and by the actual setting of the midwinter sun at hole #28. Had the seasons been of equal length (91 days), the marker would have sat at the four quadrant points (that is, at holes #14, #28, #42 and #56) at the very time of the equinoxes and solstices. In reality, summer and spring are each about 93 days long while autumn and winter are approximately 89.
This also means that the Aubrey Circle could have been used as a calendar independent of the movement of the sun thus making the 13-month scheme, similar to Thom's 16-month calendar, a totally artificial one. By the same token, in our modern days we do not need visual observation of the sun in order to keep track of days and dates. We merely refer to a wall or desk calendar which, obviously, is sufficient in itself. The function served by observation of the movement of the sun along the horizon at Stonehenge was, therefore, principally that of synchronization, of making sure that the man-made calendar continued to maintain coordination with the celestial phenomena it was designed to reflect. This aspect of the Stonehenge operation, or, at least, that of the Aubrey Circle, closely resembles a ceremony which was regularly conducted in ancient Babylon and which was known as the "Binding of the Pleiades" (note the reference in the Book of Job(14)), and sometimes as the "Binding of the Seasons." During this ceremony the celestial position of that constellation was related, in a continuing cycle, to the journey of the sun along its zodiacal path.(15) And, incidentally, the geometery of Stonehenge is perfectly adaptable as a zodiac plotter by correlating the annual azimuthal shift of sunrises with the nightly procession (and precession) of the stars and planets across the local meridian (firmly established at the site as the azimuth line that passes through the center of the circle and trilithon #54). Indeed, internal evidences testifying to the use of the monument as an astrological indicator are compelling, and form the basis of another paper.
The synchronization of the day-marker, as it travelled around the Aubrey Circle, with the azimuthal shift of the sun, is tabulated as follows:
One day intercalated: Year complete.
The size of the arc of the horizon over which the sunrises occur during a year varies with the latitude of the locality. At the latitude of Stonehenge (51.2° N) the azimuthal shift of sunrises is about 78°. At the latitude of New York City, the annual shift is about 64°. The higher the latitude, the greater the shift - and conversely. On the equator, the annual shift of sunrises along the horizon exactly equals the difference in the sun's maximum northerly and southerly declinations - that is, 23.5° + 23.5° = 47°.
In addition, the sun's maximum declination is slowly decreasing at a rate of about 1/2° in 4000 years. At the latitude of Stonehenge a 1/2° decrease in the sun's maximum declination results in a 1.8° decrease in the value of the arc of the horizon over which sunrises occur in the course of one year. This means that in 1977, when touching the horizon at Stonehenge during the summer solstice, the sun was 1.8/2 or .90° closer to the equator than it was at summer solstice 4000 years ago. For a 2000 year span it would be approximately half that value. It can be seen that in this phenomenon there exists a possible means for determining, with near accuracy, the approximate date of construction of specific sites where it has first been established that celestial alignments were originally incorporated in the design of the structures. The accuracy of dating by this method depends mainly upon the accuracy with which the original alignments were made. Unfortunately, the utterances of other investigators notwithstanding, that such alignments were always accurately laid out can never be positively ascertained. The skill of the builders as exhibited generally within such structures must certainly be taken into account. On the other hand an investigation into this aspect of Stonehenge reveals an amazing degree of accuracy evidenced in the layout and construction of the monument. Consider the following:
Though many of the holes of the Aubrey Circle are not spaced exactly or uniformly, either with respect to a common center or to each other, holes #56, 7, 14, 21, 28, 35, 42 and 49 were placed with such extreme care that lines connecting their centers circumferentially are of exactly the same length. In addition, lines connecting diametrically opposed pairs, that is #56 with #28, #7 with #35, etc., intersect at a fine point as though the alignments were laid out with the use of modern surveying equipment. The centers of these eight holes lie precisely on the circumference of a circle and dissect that circle into eight equal segments. The basic pattern therefore appears to be that of an accurately delineated octagon.
A line drawn from the center of the circle tangent to the left edge of hole #56 will be tangent to the left edge of stone hole B, to the left edge of stone hole A, both positioned along the axis of the avenue, while also being tangent to the right edge of the Heel Stone. By visually lining up the stones in holes A and B, and by keeping the Heel Stone tangent to this line of sight, an observer would be assured that he was standing on the axis line of the monument. In this way he could adjust his viewpoint to a fine degree of accuracy, in the same way that a modem navigator uses a pelorus, and be certain that his sights were always being taken from the exact same position.
It was not my intention in this paper to discuss the truly megalithic elements of Stonehenge other than the Heel Stone. The circle of Sarsen stones and the trilithon arches are commonly assumed to have been erected a few centuries following the original digging of the Aubrey holes but even these impressive stones and archways seem to have been laid out with the greatest accuracy. Consider:
The Sarsen Circle of 30 upright stones that are ranged within the central part of the monument is approximately 104 modem feet in outside diameter. The Heel Stone is exactly twice this distance from the outer edge of the Sarsen Circle.
A line connecting stone #93 with mound #92 is exactly tangent to the lower outer edge of the Sarsen Circle.
A line connecting stone #91 with mound #94 is exactly tangent to the upper outer edge of the Sarsen Circle.
The five trilithon arches, #s 51-52, 53-54, 55-56, 57-58 and 59-60, have angular distances, center-to-center between each pair, of exactly 60° as measured from the center of the circle. The angular distance between the center of trilithon #51-52 clockwise around the trilithon horseshoe to the center of trilithon #59-60 equals 4 x 60 or 240°. The angular distance between the center of trilithon #59-60 clockwise to the center of trilithon #51-52 is 120°. This 120° arc is bisected exactly in half by the line CBA which, as already indicated, seems to be the central axis of the entire structure.
This arrangement of the trilithon arches, so angularly symmetrical, rules out the possibility that they were used as celestial sight lines in conjunction with the center of the circle. In fact there are no astronomical alignments, nor could there have been any at the time the monument was constructed, that would conform to the azimuths of these trilithons. Gerald Hawkins, in his work on Stonehenge, it is true, did use these arches in sun and moon alignments but only by employing the shotgun method previously described, that is, by combining specific arches with extraneous features to provide the alignments.(16) If you throw enough stones you are bound to hit something, but this does not testify to accuracy. I have already shown that the Aubrey Circle of 56 holes, with the center of the circle as the sighting point and the bank as an artificial horizon, would have given any celestial azimuth required. Hawkins' shotgun method is therefore superfluous. (For a comparison of the kind of accuracy that can be achieved by my method as opposed to that of Hawkins', see Appendix III, KRONOS IV:2.)
I have cited these impressive examples of accuracy of measurements and alignments as evidence that the architects and engineers who built the structure were highly skilled and expert in their work. From these evidences we can therefore assume that if the Heel Stone was originally set up as the foresight in a celestial alignment, the Stonehenge builders would not have misaligned it to any appreciable degree.
An important aspect of sunrise must be pointed out here, and that is that the sun climbs obliquely southward as it rises, and that its appearance above the horizon can be said to take place in three distinct phases:
1. Upper limb tangent to horizon.
2. Sun bisected by horizon.
3. Lower limb tangent to horizon.
The obliquity of the angle of sunrise varies with the latitude and the declination. Some examples follow:
An observer at Stonehenge would see the sun appear on the horizon about 39° to the northeast of his position. As it rose, the sun would cross the heavens in a path that would take it south of the observer, reaching its greatest altitude on the meridian (the north-south line that passes through the point of observation). It would then swing northward again, setting about 39° N of W. The path that the sun describes in this daily journey is called a diurnal circle.
At Stonehenge, from upper limb tangent to the horizon, to lower limb tangent to the horizon, there is an angular displacement of the sun's disk of about .90° to the south or the observer's right. In other words, from first flash to fully visible on the horizon, the sun moves southward by .90°. Today the first flash of summer solstice sunrise occurs a little to the left of the Heel Stone, and very nearly half the disc appears over the peak.(17) Despite photographic evidence which has been presented as proof, (18) this does not accord well with the actual moment of sunrise. In fact, Atkinson has long claimed that not only does the sun not rise directly over the Heel Stone today but that it will not do so "for more than a thousand years."(19) What is of even greater significance, Atkinson also states that "when Stonehenge was built it [the sun] rose even further to the left."(20) This, however, is only true if we adhere to the date commonly assigned to the building of the monument, that is approximately 2000 B.C. Formerly, such a date had only been arbitrarily fixed but in 1966-67 a new criterion was offered for determining the age of the monument. Some antlers were discovered under one of the stones and in the fill of some of the holes. These were offered for radiocarbon dating. But as the Lamont Geological Observatory of Columbia University as well as the Radiocarbon Laboratory of the University of Pennsylvania attested, antlers are generally unreliable for radiocarbon dating, being easily contaminated and made to yield invalid dates. In disregard of these facts, MacKie has recently applied the just as controversial tree-ring calibration to these radiocarbon dates and thus pushed the age of Stonehenge even farther back, allotting the construction of phase I of the monument to 2800 B.C (22)
Meanwhile, everyone seems to have shied away from attempting to prove the antiquity of Stonehenge through the astronomical alignments inherent in the site itself. Hawkins, who is himself an ardent supporter of the theory that the monument is at least 4000 years old, has judiciously backed away from attempting to prove it by solar or lunar alignments implicit in the design of the structure and has left the dating controversy to the archaeologists.(23) In fact, as the first one of five criteria regarding the acceptability of proposed astronomical sites, Hawkins offers this - that construction dates should not be determined from astronomical alignments.(24) On the other hand, Thom, who today is considered the greatest authority on archeoastronomy, has no qualms in dating astronomical sites by astronomical retrograde calculations.(25) I have therefore applied a similar method to Stonehenge.
Now students of the Velikovskian hypothesis will at once inform me that retrograde calculation is invalid if, as Velikovsky assumes, the present celestial order was not established until the 7th century B.C. But, for the time being, allow me to use the very method that many of his detractors have in the past used against his theory.
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Table 1 lists calculations of the azimuth values for the three significant aspects of summer solstice sunrise at various epochs - the present, 2000 years ago (i.e. 10 B.C.) and 4000 years ago (2000 B.C.) This information is also expressed diagrammatically (see Drawing 7), showing the relationship of each of the azimuths to that of the Heel Stone as viewed from the center of the Aubrey Circle (51.3° E of N). Some astute critic will now notice that my sunrise diagrams do not conform to that shown by Newham in his work.(26) This is not a discrepancy. The principal cause of the difference is that Newham's amplitudes are related to a perfect horizon and not, as in my diagrams, to the actual horizon as it exists at Stonehenge. This is explained in more detail in Appendix IV.
Analysis of the data now shows that, as Atkinson himself stated, all three aspects of summer solstice sunrise for 2000 B.C. occurred too far to the north of the Heel Stone if it had been set in its present position at that date. After the passage of 2000 years the points of sunrise would have shifted southward along the horizon by about .45° closer to the stone. Of the three sunrise azimuths calculated for circa 10 B.C., only that of lower limb tangent to horizon (shaded block) was close enough in value to that of the Heel Stone. But even if, as Velikovsky assumes, it was the first flash that the ancients considered as the actual moment of sunrise, (27) upper limb tangent to horizon at 10 B.C. was much closer in azimuthal value to the Heel Stone than it was in 2000 B.C. The actual moment of sunrise, however, might not have been viewed in the same way by all ancient peoples and logic tells us that the sun has not really risen until its full orb is brought into view. In 10 B.C. the sun sat on the horizon only about .1° north of the stone's peak, but so slow is the change (decrease) in the obliquity of the ecliptic that the sun did not sit exactly atop the peak of the stone at summer solstice for another 400 to 450 years. What this means is that even by using the uniformitarians' own method of retrograde calculation, the Heel Stone could not be said to have been set up, nor the Aubrey holes dug, as early as 2000 B.C. (let alone 2800 B.C.) if, as it is usually claimed, the monument was constructed precisely with the summer solstice alignment in view. Allowing a tolerance of ±.1° for possible construction and/or sighting errors, circa 10 B.C. seems to be the earliest date wherein the Heel Stone could have lined up with any of the three significant aspects of summer solstice sunrise. In other words, if the Stonehenge builders, at the time of construction, set up the Heel Stone to act as the foresight in such a solstitial sunrise alignment, they would have had to have done so within the period circa 10 B.C. up to the date of the first absolute historical knowledge of the monument's existence. Moreover, despite the fact that this conclusion has been arrived at through a uniformitarian method, it holds true regardless of whether or not the present celestial order was established in the 7th century B.C. since the date at which the Heel Stone could have accurately lined up with the solstitial sunrise falls entirely outside the time of Velikovsky's postulated cosmic catastrophes.
. . . to be continued
NOTES1. Colin Renfrew, Before Civilization, Alfred A. Knopf, New York, 1973, p. 238.
2. R. S. Newall, Stonehenge Official Guide-Book, H. M. Stationery Office Press, Edinburgh, 1959, p. 13.
3. Ruth Brindze, The Story of Our Calendar, Vanguard, New York, 1949, p. 13.
4. Sylvanus G. Morley, The Ancient Maya, Stanford University Press, 1947, p. 333.
5. Colin Renfrew, op. cit., pp. 239-240.
6. The Book of Exodus, 34:22.
7. The Book of Chronicles II, 24:23.
8. Ruth Brindze, op. cit., p. 46.
9. Encyclopedia Americana, International Edition, 1975, Vol. 2.
10. Sylvanus G. Morley, op. cit., p. 293.
11. The Waverly Encyclopedia, Amalgamated, London, 1952.
12. Alexander Thom, Megalithic Sites in Britain, Oxford University Press, reprinted and corrected edition, 1974, pp. 109-112.
13. Encyclopaedia Britannica, 1959 edition, Vol. 4, p. 574.
14. The Book of Job, 38:13.
15. A. Hyatt Verrill, America's Ancient Civilizations, Putnam's, New York, 1935.
16. Gerald S. Hawkins, Stonehenge Decoded, Doubleday, New York, 1965, p. 110.
17. R. S. Newall, op. cit.
18. Gerald S. Hawkins, Beyond Stonehenge, Harper & Row, New York, 1973, pp. 41, 300.
19. Immanuel Velikovsky, "On Decoding Hawkins' Stonehenge Decoded," in the May 1972 issue of Pensée, p. 27.
22. Euan W. MacKie, "Megalithic Astronomy and Catastrophism, " in the Winter 1974-75 issue of Pensée, pp. 18-19.
23. Gerald S. Hawkins, op. cit., p. 267.
24. Ibid., p. 288.
25. Alexander Thom, Megalithic Lunar Observatories, Oxford University Press, reprinted and corrected edition, 1973, p. 81.
26. C. A. Newham, The Astronomical Significance of Stonehenge, John Blackburn, Leeds, 1972, p. 32.
27. Immanuel Velikovsky, op. cit., p. 28.