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ABSTRACT. This paper examines the astro-orientation, geometry and metrology of a random sample (n=5) of Mesopotamian ziggurat/temples (3000-550 BC) with archaeological site plans, GIS/satellite imaging, and astronomical software. The... more
ABSTRACT.  This paper examines the astro-orientation, geometry and metrology of a random sample (n=5) of Mesopotamian ziggurat/temples (3000-550 BC) with archaeological site plans, GIS/satellite imaging, and astronomical software.  The major finding is that ziggurats appear orientated to sun rise/set at the solstices and equinox, moon rise/set at the midwinter/midsummer major/minor standstills, and/or Venus rise/set at zenith/nadir passage.  Evidence is also presented that the length/width ratios of rectangular ziggurat platforms and temple floorplans were based on 3:4:5 (n=2), 20:21:29 Pythagorean Triples (n=2) and 1:1:√2 square (n=1).  The best fit for integer linear units of measurement are the Mesopotamian cubit (n=2) for length/width and (unexpectedly) Egyptian Old Kingdom setat (n=3) for area.
ABSTRACT: The Altar of the Twelve Gods (ΒΩΜΟΣ ΔΩΔΕΚΑ ΘΕΩΝ) was constructed in the Athenian Agora, NW of the Acropolis, at the direction of Pisistratos the Younger, Archon of Athens, 522/521 BC (Thucydides). In 1934, archaeologists... more
ABSTRACT:  The Altar of the Twelve Gods (ΒΩΜΟΣ ΔΩΔΕΚΑ ΘΕΩΝ) was constructed in the Athenian Agora, NW of the Acropolis, at the direction of Pisistratos the Younger, Archon of Athens, 522/521 BC (Thucydides).  In 1934, archaeologists excavated a marble statue base in situ next to a rectangular limestone hypaethral edifice on the Panathenaic Way.  Its inscription reads “Leagros, the son of Glaukon, made the dedication / To the Twelve Gods”.  Although the Altar is now buried under the Athens-Piraeus railway tracks, the author surveyed the exposed SW corner (12 September 2017) with a Gurley 20” theodolite (for solar observations) to Ground Truth published (magnetic compass) azimuths.  This paper presents counter-evidence rejecting the interpretation that the Altar takes its orientation from the Panathenaic Way (Camp, 1986).  Rather, the axis of the Altar’s peribolus wall openings is oriented to horizon points consistent with Graeco-Roman hypaethral architectural design principles (Vitruvius), viz.:  Full Moon rise nearest the Midwinter Minor Standstill (+18.66° decl.) and set nearest the Equinox Minor Standstill (-5.1° decl.).  The significance of these lunar standstill alignments is that they connote systematic local and long-term luni-solar observations in the century preceding the 19-year luni-solar cycle proposed by Meton of Athens (ca. 432 BC): i.e., the NE peribolus opening framed the last of a series of Midwinter Lunar Eclipses observable in Athens every 19-years, viz.:  Partial Eclipse 29 December 560 BC; Total Eclipse 29 December 541 BC; and Partial Eclipse 30 December 522 BC— this last coinciding with the Altar’s construction under Pisistratos the Younger.
ABSTRACT: The Ara Pacis Augustae (Altar of Augustan Peace) is examined as a shrine of light consistent with the astro-orientation principles of Roman architect Vitruvius (c.25 BC). Italian archaeologists excavated (1937-38) and... more
ABSTRACT:  The Ara Pacis Augustae (Altar of Augustan Peace) is examined as a shrine of light consistent with the astro-orientation principles of Roman architect Vitruvius (c.25 BC).  Italian archaeologists  excavated (1937-38) and relocated the altar along Rome’s Tiber River – rotating it 75º counter-clockwise from the original orientation.  While its magnificent marble sculpture may be viewed at the Museo dell’Ara Pacis, a key astronomical component of the  altar’s architectural design has until now remained encoded on a paper site plan.  The author calculated the horizon declination (+11.3º decl.) of the altar’s original northeast opening with Program STONEHENGE (Hawkins 1983, 328-330), Guglielmo Gatti’s 1938 site map, and Google Earth satellite imagery: True Azimuth ≈ 75º; Latitude/Longitude = 41° 54’ 10.47” N/12° 28’ 44.60” E; Elevation ≈ 10 meters ASL; and Horizon Altitude ≈ +1.1º.  The Ara Pacis Augustae was dedicated in 9 BC (Moretti 1947,7).  Analysis shows that the axis of the Ara Pacis enclosure’s northeast opening originally was oriented to the rising Sun (+11.0º decl.) on both April 21st and August 27th.  However, the iconography of the Ara Pacis supports an interpretation that only the April 21st sunrise orientation was intended, because each sculpture of the “Tellus” frieze (young woman, flowing amphora, pair of fishes, ram, bull, infant twins) uniquely mirrors the astronomy: Venus (Morning Star phase) and the Zodiac constellations Aquarius-Pisces-Aries-Taurus-Gemini at dawn on the festival of Par ilia (Pales, goddess of shepherds), 21 April 9 BC.  This date coincides with the founding of Rome on 21 April 1 ab urbe condita (753 BC) as recorded by Roman historian Marcus Terentius Varro.  What could be a more fitting venue than the Museo dell’Ara Pacis for exhibiting a virtual 3D animation of the annual sacrifice connecting the Pax Augusta of the SPQR to the Cosmos of the Immortal Gods on the dawn of the Dies Natalis Romae?

ASTRATTO:  L'Ara Pacis Augustae è esaminata in base al precetto astro-architettonico di Vitruvio secondo cui <<…chi si professa architetto dovrebbe essere ben versato in …astronomia e nella teoria dei cieli>>  (De Architectura, I.i.3; IX).  Nel ricollocare l'Ara Pacis per l'esposizione delle sue magnifiche sculture marmoree nel nuovo Museo dedicato all’Ara Pacis (1937-1938), l'altare fu ruotato di 75°, cancellando così ogni allineamento astro-architettonico originario. Poiché la mappa del sito dell'archeologo Guglielmo Gatti del 1938 documenta l'orientamento originale dell'altare, l'autore è stato in grado di calcolare la declinazione (δ) del sole sull’orizzonte astronomico (+11,3ºδ) riferito all’apertura nord-est dell'altare utilizzando i programmi STONEHENGE (Hawkins 1983, 328-330) e Google Earth Pro Digital Elevation Model, con i seguenti dati:  True Azimut ≈ 75º; Latitudine/Longitudine = 41°54'10,47"N/ 12°28'44,60"E; Altitudine ≈ 10m slm; e Altezza angolare dell'orizzonte locale ≈ +1,1º.

Dato che l'Ara Pacis fu inaugurata nel 9 a.C. (Moretti 1947, 7), il planetario digitale Starry Night Pro ha calcolato che il vettore astro-orizzonte dell'apertura nord-est dell'Ara Pacis era originariamente orientato verso il Sole nascente (+11,0ºδ) sia il 21 aprile che il 27 agosto del 9 a.C.  Tuttavia, l'iconografia sul fregio << Tellus >> dell'esterno nord-est supporta l'interpretazione che solo l'alba del 21 aprile fosse significativa, perché ogni elemento scultoreo del fregio – giovane donna (Venere), anfora fluente (Acquario), coppia di pesci (Pesci), ariete (Ariete), toro (Toro), gemelli neonati (Gemelli) – rispecchia l'ascesa eliaca di Venere/Stella del Mattino in Ariete tra le cinque costellazioni dello zodiaco primaverile viste dall'altare sacrificale interno all'alba della Festa di Palilia (Parilia) (Pales, dea dei pastori), il 21 aprile 9 a.C.  In questo giorno si commemora la fondazione di Roma, il 21 aprile 1 ab urbe condita (AUC) nella cronologia di Marcus Terentius Varro, cioè la 93a iterazione nel periodo sinodico Terra-Venere di 8 anni dell'ascesa eliaca di Venere/Stella del Mattino nella costellazione dell'Ariete sul Dies Natalis Romae, 21 aprile 753 a.C.
ABSTRACT: The Tall Gnomon at Gaocheng, Dengfeng Township, Henan Province, China (34°24’8.73”N, 113°8’26.23”E) is described in scholarly literature as tracking changes in the gnomon’s shadow at noon (meridian transit) between midsummer and... more
ABSTRACT: The Tall Gnomon at Gaocheng, Dengfeng Township, Henan Province, China (34°24’8.73”N, 113°8’26.23”E) is described in scholarly literature as tracking changes in the gnomon’s shadow at noon (meridian transit) between midsummer and midwinter.  For example, the Yuan History (Yuan Shih) records that the sun’s shadow cast near the winter solstice on 14 December 1278 CE measured 76.7400 Chinese feet (chi).  However, the 128chi horizontal graduated template scale (kuei piao) of the Tall Gnomon is 40% longer than what is required to measure the sun’s longest shadow at winter solstice. Using GIS and astro-archaeological computer modeling, nocturnal astronomical targets (i.e., midsummer full moon, Venus and bright stars) are investigated to account for the construction of the extra 51chi in length of the Tall Gnomon’s template scale.  Evidence is also presented confirming that the Tall Gnomon solstice observations in the Yuan History were made at Beijing, rather than Gaocheng.
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摘要:在已有學術文獻的描述中,位於河南登封藁城(34°24'8.73“N,113°8'26.23”E)的圭表是用來追蹤表柱從夏至到冬至之間每天正午時分陰影長度的儀器。例如,據《元史》記載,1278年12月14日臨近冬至時,表柱影子長度為76.7400尺。然而,圭表的水平刻度總長128尺,比表柱在冬至時最長的影子多出40%。GIS和天文考古計算機建模表明,圭表水平刻度多出來的51尺與其它天象的觀測有關,如太陽以外的其它天體、仲夏夜滿月、金星以及其它明亮的恆星。同時,還有證據證明《元史》中夏至和冬至表柱陰影長度的觀測地點是北京,並非藁城。
ABSTRACT: Because Town Creek Indian Mound, Montgomery County, North Carolina is the only reconstructed Southern Appalachian Mississippian mound based on both archaeological excavation and overhead photogrammetry, the site is ideal for... more
ABSTRACT:  Because Town Creek Indian Mound, Montgomery County, North Carolina is the only reconstructed Southern Appalachian Mississippian mound based on both archaeological excavation and overhead photogrammetry, the site is ideal for applying the techniques of astro-archaeology.  Preliminary evidence is presented for equinox, summer solstice, and midwinter full moon orientation involving the exterior mound ramp, Town House interior smoke hole-altar, and smoke hole-fire pit.  Implications of the new findings for Muskogean ethnographic literature as well as future research at other South Appalachian Mississippian sites (e.g., Ocmulgee Earth Lodge) are discussed.
ABSTRACT: The rules for orientation of Early Christian oratories or chapels in Ireland and Scotland have been the subject of scholarly speculation for some time. By applying the techniques of archaeoastronomy (Hawkins 1983) to monastic... more
ABSTRACT:  The rules for orientation of Early Christian oratories or chapels in Ireland and Scotland have been the subject of scholarly speculation for some time. By applying the techniques of archaeoastronomy (Hawkins 1983) to monastic oratories, new light is shed onto the history of Early Christianity. It now appears that oratories were calendrically oriented to sunrise on saint’s days of the Celtic Early Christian Church and pagan solar bonfire days.
The Ara Pacis Augustae is examined according to Vitruvius' astro-architectural precept that "[O]ne who professes himself an architect should be well versed in…astronomy and the theory of the heavens" (De Architectura, I.i.3). In... more
The Ara Pacis Augustae is examined according to Vitruvius' astro-architectural precept that "[O]ne who professes himself an architect should be well versed in…astronomy and the theory of the heavens" (De Architectura, I.i.3). In relocating the Ara Pacis so that its magnificent marble sculptures could be displayed in the new Museo dell'Ara Pacis (1937-1938), the altar was rotated by 75°, thereby erasing any original astro-architectural alignment. However, because archaeologist Guglielmo Gatti's 1938 site plan documents the altar's original orientation, the author was able calculate the original astro-horizon declination (δ) vector (+11.3ºδ) of the altar's northeast opening with Program STONEHENGE (Hawkins 1983, 328-330) and Google Earth Pro Digital Elevation Model, viz.:  True Azimuth ≈ 75º; Latitude/Longitude = 41°54’10.47”N / 12°28’44.60”E; Elevation ≈ 10m ASL; and Local Horizon Altitude ≈ +1.1º. 

Given that the Ara Pacis was dedicated sometime in 9 BC (Moretti 1947, 7), Starry Night Pro digital planetarium calculated that the astro-horizon vector of the Ara Pacis’ northeast opening was originally oriented to the rising Sun (+11.0ºδ) on both April 21st and August 27th in 9 BC.  However, the iconography on the northeast exterior’s “Tellus” frieze supports an interpretation that only the April 21st sunrise was significant, because each frieze sculptural element —  young  woman (Venus), flowing amphora (Aquarius), pair of fishes (Pisces), ram (Aries), bull (Taurus), infant  twins (Gemini) — mirrors Venus/Morning Star’s heliacal rise  in Aries amid the five Vernal Zodiac constellations as viewed from the interior sacrificial  altar at dawn on the Palilia (Parilia) Festival  (Pales, goddess of shepherds), 21 April 9 BC.  This day commemorates the founding of Rome on 21 April 1 Ab urbe condita (AUC) in the chronology of Marcus Terentius Varro, i.e., the 93rd iteration in the 8-year Earth-Venus Synodic Period of Venus / Morning Star’s heliacal rise in the constellation Aries on the Dies Natalis Romae, 21 April 753 BC.

L'Ara Pacis Augustae è esaminata in base al precetto astro-architettonico di Vitruvio secondo cui <<…chi si professa architetto dovrebbe essere ben versato in …astronomia e nella teoria dei cieli>>  (De Architectura, I.i.3; IX).  Nel ricollocare l'Ara Pacis per l'esposizione delle sue magnifiche sculture marmoree nel nuovo Museo dedicato all’Ara Pacis (1937-1938), l'altare fu ruotato di 75°, cancellando così ogni allineamento astro-architettonico originario. Poiché la mappa del sito dell'archeologo Guglielmo Gatti del 1938 documenta l'orientamento originale dell'altare, l'autore è stato in grado di calcolare la declinazione (δ) del sole sull’orizzonte astronomico (+11,3ºδ) riferito all’apertura nord-est dell'altare utilizzando i programmi STONEHENGE (Hawkins 1983, 328-330) e Google Earth Pro Digital Elevation Model, con i seguenti dati:  True Azimut ≈ 75º; Latitudine/Longitudine = 41°54'10,47"N/ 12°28'44,60"E; Altitudine ≈ 10m slm; e Altezza angolare dell'orizzonte locale ≈ +1,1º.

Dato che l'Ara Pacis fu inaugurata nel 9 a.C. (Moretti 1947, 7), il planetario digitale Starry Night Pro ha calcolato che il vettore astro-orizzonte dell'apertura nord-est dell'Ara Pacis era originariamente orientato verso il Sole nascente (+11,0ºδ) sia il 21 aprile che il 27 agosto del 9 a.C.  Tuttavia, l'iconografia sul fregio << Tellus >> dell'esterno nord-est supporta l'interpretazione che solo l'alba del 21 aprile fosse significativa, perché ogni elemento scultoreo del fregio – giovane donna (Venere), anfora fluente (Acquario), coppia di pesci (Pesci), ariete (Ariete), toro (Toro), gemelli neonati (Gemelli) – rispecchia l'ascesa eliaca di Venere/Stella del Mattino in Ariete tra le cinque costellazioni dello zodiaco primaverile viste dall'altare sacrificale interno all'alba della Festa di Palilia (Parilia) (Pales, dea dei pastori), il 21 aprile 9 a.C.  In questo giorno si commemora la fondazione di Roma, il 21 aprile 1 ab urbe condita (AUC) nella cronologia di Marcus Terentius Varro, cioè la 93a iterazione nel periodo sinodico Terra-Venere di 8 anni dell'ascesa eliaca di Venere/Stella del Mattino nella costellazione dell'Ariete sul Dies Natalis Romae, 21 aprile 753 a.C.
BACKGROUND: While New England’s drywall stone chambers are typically attributed to Anglo-American farmers AD 1600—1900 (Neudorfer 1980, 2-3), new archaeological evidence also suggests an Early Christian monastic presence ca. AD 500—1200... more
BACKGROUND:  While New England’s drywall stone chambers are typically attributed to Anglo-American farmers AD 1600—1900 (Neudorfer 1980, 2-3), new archaeological evidence also suggests an Early Christian monastic presence ca. AD 500—1200 consistent with the "Terra Repromissionis Sanctorum" of the NAVIGATIO SANCTI BRENDANI ABBATIS (Goodwin 1946, Selmer 1959, Severin 1978).
NULL HYPOTHESIS:: “There is no physical evidence of pre-medieval Celtic monastic
provenance for Chamber #32, Windsor County, Vermont, USA.”
METHODOLOGY & FINDINGS: Test for Presence/Absence along the following lines of evidence to falsify the Null Hypothesis:
—ASTRO-ARCHAEOLOGY: Solar alignments signaling the Divine Hours commemorating the crucifixion of Jesus prior to Passover (first Full Moon after the Vernal Equinox). The single window of Gallarus Oratory’s (Séipéilín Ghallarais, Co. Kerry) admits sunlight at 9am (Terce, IIIrd Hour, Mark 15:25) on the Vernal Equinox. The single window of Vermont Chamber #32 admits sunlight on the Vernal Equinox which extinguishes on a Romano-British Chi-Rho (XP) at 3pm (None, IXth Hour, Mark 15:34), i.e., a metaphor for the death of "Christus Sol Verus" (Sedulius Scottus, ca. 850; Thomas 1985, Fig 5 (5), 89; Tiede 2001). 
—ICONOGRAPHY: Hiberno-Latin "nomina sacra" and Romano-British rock art. Vermont
Chamber #32 petroglyphs include: XP (Greek: ChRist), A(lpha), O(mega), Antr(on; Greek: cave) (Revelation 1:8, 21:6-7, 22:13; Fell 1983, 183; Thomas 1985, Fig 5(5) & (7), 89); and a Sun Cross slab (Dexter 1986).
—METROLOGY: Floor-plan dimensions of Celtic Early Christian rectangular oratories.
Rathlin O'Birne Isle #10 (Co. Donegal) and Vermont Chamber #32 share a common
floor-plan, viz., a quasi-Pythagorean Triple (13:26:29) length-to-width ratio in
commensurate 13x26 Justinian Byzantine "σπιθαμή" (Walsh 1983, 61).
—ARCHAEOBOTANY: Pollen in sediment cores from British Isles plants
introduced into New England ca. 1500—800 BP (https://www.neotomadb.org/).
To date, the presence of two native European plant species is confirmed by pollen in sediment cores:  Plantago lanceolata in New York ca. AD 756 (Spear & Miller 1976)  and P. major in Québec ca. AD 1169 (Comtois, 1982). These two introduced plants were used in Algonkian (Tantaquidgeon 1995, 130) and Cherokee (Moerman 1986, 350) traditional medicine as analgesics.
Background. Jesuit Father Paul Le Jeune (1636) observed that the Indians of Nouvelle France "…have recourse to the Sky in almost all their necessities and respect the great bodies in it above all creatures." (Mavor 1989, 2). New England's... more
Background. Jesuit Father Paul Le Jeune (1636) observed that the Indians of Nouvelle France "…have recourse to the Sky in almost all their necessities and respect the great bodies in it above all creatures." (Mavor 1989, 2). New England's Algonkian (Narragansett, Ojibwa and Choctaw) and Iroquois (Cayuga) tribes celebrated seasonal ritual festivals regulated by the Sun and Moon (Narragansett: Nippaûus and Nanepaûshat). Puritan theologian Roger Williams (1643) noted that the Narragansetts "have thirteen Moneths according to the several Moones; and they give to each of them significant names: as, Sequanakeeswush (Spring moneth), Nepunnakeeswush (Summer moneth), Taquontikeeswush (Harvest moneth), Paponakeeswush (Winter moneth), etc….. They are punctuall in measuring the Day by the Sunne, and their Night by the Moon and the Starres…." (Williams 1643, 62, 66). Moreover, "The Ojibwa and related Algonkian bands of the upper Great Lakes area once scheduled their ritual year in reference to celestial events. A special group of medicine men, the Wabeno or 'White Light of Dawn' shamans, taught a cycle of interrelated celestial legends to their apprentices through formal instruction. …The Wabeno were responsible for celestial and lunar time-keeping, using calendar sticks and related notational devices [e.g., birch bark scrolls]. Under Wabeno direction, a series of seasonal transition rituals occurred at specific intervals, including solstices and equinoxes. These public or corporate-level duties were concerned with the harmonious balance between man, the animate landscape, the spirit world, and the band's food and medicinal resource needs." (Conway 1992, 236, 240; Swanton 1931, 44, 101). The ethnographic literature of Algonkian and Iroquoian tribes specifically references a two-week Midwinter Festival timed by the Pleiades and lunar phases (Speck 1949). Therefore, "It would be an anomaly if the native people who inhabited New England in the past did not also regard the celestial sphere with deep interest, and commemorate their interest using materials from the local landscape." (Williamson 1984, 268).
Background. North American archaeologists interpret New England’s stone structures either as indigenous ceremonial constructs (Hoffman 2019) and/or British-American agricultural field clearing (Thorson 2002; Ives 2021). Drywall masonry... more
Background.  North American archaeologists interpret New England’s stone structures either as indigenous ceremonial constructs (Hoffman 2019) and/or British-American agricultural field clearing (Thorson 2002; Ives 2021).  Drywall masonry “niches” may simply be shelves when embedded in cairns, chambers or walls. However, luni-solar oriented standalone niches with a flat stone lintel located on elevated terrain are more likely Native American ritual altars of the sun and moon qualifying for statutory protection as a Ceremonial Stone Landscape.  Free-standing stone niches on former tribal lands were evaluated as possible altars for the Algonkian and Iroquoian two-week Midwinter Festival (Speck 1949). 

Methodology.  A preliminary proof-of-concept investigation tested for the presence or absence of a coherent pattern of luni-solar alignments timed to midwinter rites in ethnological literature, i.e., seven random  Connecticut elevated free-standing stone niches were field surveyed (GPS and theodolite) to determine true azimuth and horizon altitude.  Program Stonehenge (Hawkins 1983, 328-330) derived the respective declination to identify hypothetical luni-solar rise/set alignments. 

Results.  Three predicted Midwinter alignments were confirmed by photography 20 December 2021:
1) “Boxed-In” niche: ESE Winter Solstice Sun Rise;
2)  “See-Through” niche: ENE Midwinter Full Moon Rise and WSW Winter Solstice Sun set.
Q.E.D.

Conclusion:  Field surveys of 140+ known niches are ongoing 2022-2023.
Background. Over the last century, scholars have deciphered cuneiform texts on mathematics and astronomy (Neugebauer & Sachs 1955) associated with Mesopotamia's religious architecture, calendars and iconography (Curatorla 2007). However,... more
Background. Over the last century, scholars have deciphered cuneiform texts on mathematics and astronomy (Neugebauer & Sachs 1955) associated with Mesopotamia's religious architecture, calendars and iconography (Curatorla 2007). However, no systematic investigation of possible astronomical orientation has been made of Mesopotamia's many ziggurats and temples. The availability of geo-referenced/sub-meter resolution satellite imagery now makes such analysis feasible; despite the region's ongoing military conflicts preventing Ground Truth field survey.
BACKGROUND --- Pisistratos the Younger, archon of Athens 522/1 BCE, dedicated the Altar of the Twelve Gods in the Agora of Athens (Thucydides 6.54, 6-7). In 1934, American archaeologists excavated in situ an inscribed marble statue... more
BACKGROUND ---  Pisistratos the Younger, archon of Athens 522/1 BCE, dedicated the Altar of the Twelve Gods in the Agora of Athens (Thucydides 6.54, 6-7).  In 1934, American archaeologists excavated in situ an inscribed marble statue base set against the west opening of a stone peribolos enclosure in the Agora on the Panathenaic Way north of the Acropolis.  The inscription reads “Leagros, the son of Glaukon, made the dedication /To the Twelve Gods”.  Today, only the southwest corner of the peribolos foundation is visible, as the ISAP Athens-Piraeus railway right-of-way covers the remainder.
--- RESEARCH QUESTION ---  Is the orientation of the Altar of the Twelve Gods simply random?  Does it take “its orientation from the street” (Camp 1992, p. 45) or perhaps from an astronomical alignment of significance in the Archaic Athenian festival calendar? 
--- DATA ---  Four published archaeological site plans of the Agora show that the Altar has a 31° azimuth deviation from facing the adjacent curbing of the Panathenaic Way (Crosby 1949, Fig. 2, p. 85; Gadbery 1992, Fig. 1, p. 448; Camp 1992, Fig, 66, p. 89; Mauzy 2006, Fig. 10, p. 9).  Preliminary astro-archaeological data was compiled from archival site plans curated by the American School of Classical Study at Athens (ASCSA), NOAA Magnetic Field Calculator (IGRF12), aerial/satellite imagery, and Google Earth’s  Digital Elevation Model, viz.: Latitude = North 37° 58’ 32.89’; Elevation = 54 meters ASL, True Azimuth ≈ 72.5° ; Date = 522/1 BCE; and horizon Altitude = +1° 30’.  A Ground Truth field survey with theodolite (for sun-shot corrected azimuths and horizon altitudes) is being planned for mid-2017.
--- RESULTS ---  Analysis with Program Stonehenge (Hawkins 1983) and Starry Night Pro Plus-6 digital planetarium indicates that the northeast opening of the Altar’s peribolos wall was oriented to the point (+13° 29’ declination) on Likavitos Hill where the constellation Pleiades rose heliacally (apparent magnitude = 1.2), 1-7 May 522/1 BCE. 
--- CONCLUSION ---  If field survey confirms the peribolus azimuth error to the heliacal rise of the Pleiades is significantly less than the azimuth error to the curb facing the Panathenaic Way, then one may reasonably conclude that the Altar of the Twelve Gods takes its orientation from the Archaic Attic-Boeotian calendric tradition that, “When the Pleiades, daughters of Atlas, are rising, begin your harvest….”  (Hesiod, 380).  Moreover, both the Old (+13° 21’declination, ca. 550 BCE) and New (+14° 00’ declination, ca. 350 BCE) Temples of Dionysos Eleutherios on the south slope of the Athenian Acropolis have the same Pleiades heliacal rise orientation (Boutsikas 2008, Table 1, p. 6).  The redundant Pleiades orientation discovered in three sacred structures is almost certainly a consequence of the Cult of Dionysus having been introduced to Athens in Attica from Eleutherai in Boeotia (AFA 2004, pp. 10-12) and serves as a Classical example of astronomy in culture.
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REFERENCES
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Association of Friends of the Acropolis (AFA), South Slope of the Acropolis: Brief History and Tour, Athens: Hellenic Ministry of Culture, First Ephorate of Prehistoric and Classical Antiquities, 2004.
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Boutsikas. Efrosyni, “Placing Greek Temples: An Archaeoastronomical Study of the Orientation of Ancient Greek Religious Structures,” Archaeoastronomy, vol. XXI (2008), 4-19.
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Camp, John Mck., Athenian Agora: Excavations in the Heart of classical Athens, New York: Thames and Hudson, 1992.
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Crosby, Margaret, ‘The Altar of the Twelve Gods in Athens,’ Hesperia Supplements, Vol. 8,  (1949), pp. 82-103, 447-450.
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Gadbery, Laura M., "The Sanctuary of the Twelve Gods in the Athenian Agora: A Revised View", Hesperia 61 (1992), pp. 447–489.
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Hawkins, Gerald S., ‘Program STONEHENGE’, Mindsteps to the Cosmos, New York:
Harper & Row,1983, pp. 328-330. 
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Hesiod of Boeotia (ca. 750 BCE), Works and Days, in The Homeric Hymns and Homerica with  an English Translation (Hugh G. Evelyn-White, trans.).  Cambridge, MA: Harvard University Press; London, William Heinemann Ltd. 1914. http://www.perseus.tufts.edu/hopper/text?doc=Hes.%20WD%20387
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Mauzy, Craig A., Agora Excavations 1931-2006 A Pictorial History, American School of Classical Studies at Athens, 2006.
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National Oceanic and Atmospheric Administration (NOAA), Magnetic Field Calculator
https://www.ngdc.noaa.gov/geomag-web/
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Thucydides , History of the Peloponnesian War, 6.54,6-7 (Benjamin Jowett trans.) Oxford: Clarendon Press, 1881.
Background. This paper contributes to the interpretation of Roman architecture by focusing on diagnostic patterns of possible astro-orientation and supplementing traditional approaches involving art motifs, inscriptions, mensuration, and... more
Background. This paper contributes to the interpretation of Roman architecture by focusing on diagnostic patterns of possible astro-orientation and supplementing traditional approaches involving art motifs, inscriptions, mensuration, and geometry (cf. Scavi et al. 2016). Prior to Roman Emperor Aurelian declaring the Cult of Mithra-Sol Invictus to be on equal standing with traditional Roman religions (AD 274), the cult already enjoyed imperial patronage as evidenced by inscriptions and temples (mithraea) constructed at Roman Army forts built along the borders the SPQR. Sparavigna 2017 reports that the NW-SE major axis of the mithraeum at Brocolitia Roman auxiliary fort on Hadrian's Wall faced the Winter Solstice sunrise. This paper reexamines Brocolita mithraeum astro-orientation and compares it with the SW-NE facing mithraeum at Dura-Europos, Syria.
ABSTRACT: In the half century since astronomer Gerald S. Hawkins proposed that Stonehenge was a "Neolithic computer" designed to forecast "a danger period when eclipses are possible" (Hawkins 1964, 1258), his interpretation has yet to be... more
ABSTRACT:  In the half century since astronomer Gerald S. Hawkins proposed that Stonehenge was a "Neolithic computer" designed to forecast "a danger period when eclipses are possible" (Hawkins 1964, 1258), his interpretation has yet to be accepted by most anthropologists (Atkinson 1966; Daniel 1967; Ruggles 1981; Aveni 1996; Magli 2012), presumably because predicting eclipses implies "... that the builders of Stonehenge...were possessed of a degree of intellectual sophistication that seems inconsistent with the usual picture of the population of S. England in the 2nd millennium B.C." (Hoyle 1966, 262).

In an attempt to bridge the inter-disciplinary divide between astrophysicists and archaeologists, this paper interprets various "numerical artifacts" of Stonehenge's architecture as a Neolithic clock to time lunar eclipses as described by Eudoxus of Cnidus (c.370 BC) involving the 56-sided polygon of Typhon and the shadow of the earth obscuring the moon. For example, we note that the architects of Stonehenge had knowledge of both Typhon's and Meton's Cycles evidenced by the 56 holes in the Aubrey circle (TPQ 3000 BC) and the 19 stones in the Bluestone Horseshoe (TPQ 1930 BC). They could time eclipse danger periods by approximating the precession of the lunar nodes (18.59992 years) as 56 years/3 = 18.66667 years. All total and partial midwinter lunar eclipses observable at Stonehenge 2000-1500 BC have been identified with the NASA Five Millennium Catalogs of Lunar and Solar Eclipses and recreated in Starry Night Pro Plus-6 digital planetarium software. We demonstrate the efficacy of the 56-Year Cycle of Typhon to time eclipses by observing the midwinter full moonrise over the Heel Stone in a period of 19+18+19 years (= 56 years), e.g., up to five midwinter total lunar eclipses: -1991 Dec 22; -1972 Dec 22; -1954 Jan 3; -1935 Jan 13; -1917 Jan 24.
Background. The Ara Pacis Augustae (Altar of the Augustan Peace, Rome, Italy, 13-9 BC) is examined as a shrine of light consistent with the astro-orientation principles of Roman architect Vitruvius (c.15 BC, IV:v:1, IV:ix:i). Italian... more
Background.  The Ara Pacis Augustae (Altar of the Augustan Peace, Rome, Italy, 13-9 BC) is examined as a shrine of light consistent with the astro-orientation principles of Roman architect Vitruvius (c.15 BC, IV:v:1, IV:ix:i).  Italian archaeologists excavated (1937-8) the altar some 10 meters under the Via in Lucina, 16 and reassembled it (rotated 75º counter-clockwise from the original) 455 meters NW along the Tiber River (Moretti 1947, 6; Andersen 2003, 5).  While "la bella figura" of its polychrome marble sculpture (Kleiner 1992, 90-99; Foresta 2011) is displayed at the Museo dell’Ara Pacis, until now, the secret of its astro-orientation has remained encoded on a paper site plan.

Data.  Computer programs “Stonehenge” (Hawkins 1983, 328-330) and “Starry Night Pro Plus 6” calculated the  horizon declination (+11.3º decl.) of the altar’s original North-East facing with the following input data from the site plan by Guglielmo Gatti c.1938 (Stampini 1970, Fig. 2, p. 36) and Google Earth: True Azimuth ≈ 75º; Latitude/Longitude = 41° 54’ 10.47” N/12° 28’ 44.60” E; Elevation ≈ 10 meters ASL; and Horizon Altitude ≈ +1.1º.  The Ara Pacis Augustae was dedicated in 9 BC for an annual ceremony by Vestal Virgins  (Res Gestae Divi Augusti, 12.2).

Results.  The axis of the Ara Pacis Augustae twin enclosure entrances was originally oriented SW-NE to the first gleam of the rising Sun (+11.0º decl.) at dawn on both 21 April and 27 August 9 BC.

Analysis & Conclusion.  The iconography of the Ara Pacis supports the interpretation that the April 21st sunrise was the date and time of the annual ceremony, e.g., the seated woman (Galinsky 1992), bull and sheep frieze above the tetra-gammadion Μαίανδρος correspond to the heliacal rise of the planet Venus as Morning Star with zodiac constellations Aries and Taurus on the horizon for the festival of Par ilia (Pales, goddess of shepherds) on 21 April 9 BC, i.e., the anniversary of the founding of Rome in 1 a.u.c. (753 BC) according to the Roman historian Marcus Terentius Varro.  Moreover, Hannah & Magli 2011 report another solar-calendric orientation for April 21st of politico-religious importance, i.e., the Pantheon’s (Hadrian, c.125 AD) oculus-to-entrance solar-noon/meridian transit alignment.  Therefore, a virtual digital 3D animation modeling Roman astro-architectural principles linking the Pax Augusta and Dies Natalis Urbis Romae deserves  exhibition at the Museo dell’Ara Pacis, Rome.
The Tall Gnomon (kao piao) of the ancient observatory at Gaocheng , Henan Province, China (34° 24’ 8.73” N, 113° 8’ 26.23” E) is described in a contemporary historical document in terms of tracking changes solar altitude at meridian... more
The Tall Gnomon (kao piao) of the ancient observatory at Gaocheng , Henan Province, China (34° 24’ 8.73” N, 113° 8’ 26.23” E) is described in a contemporary historical document in terms of  tracking changes solar altitude at meridian transit between summer and winter solstices  (Needham et al.  1954, 296-298; Sivin 2009, 183-186).  For example, the Yuan History (Yuan shih) records that the sun’s shadow cast near the winter solstice on 14 December 1278 AD measured 76.7400 feet (Needham et al. 1959, 299; Mercier 2003, 197-198; Sivin 2009, 571).  However, the 128-foot horizontal graduated template scale (kuei-piao) of the Tall Gnomon is 40% longer than what is required to measure the sun’s longest shadow at the winter solstice.  Using GIS and astro-archaeological computer modeling, additional astronomical targets (i.e., Midsummer Moon,  Venus and bright Stars) are proposed that could account for the construction of the extra 51 feet in length of the template scale.  Evidence is also presented that the solstice observations reported in the Yuan History could not have been made at Gaocheng, but rather at Beijing.

References
Mercier, Raymond.
2003  “Solsticial observations in thirteenth century Beijing.” SCIAMVS,  4:191-232.

Needham, Joseph
1959  Science and Civilization in China, III, London: Cambridge University Press.

Sivin, Nathan
2009  Granting the Seasons:  The Chinese Astronomical Reform of 1280.  New York: Springer.
Roman architect Marcus Vitruvius Pollio (c. 75-15 BC) wrote, “[O]ne who professes himself as an architect should be…acquainted with astronomy and the theory of the heavens…. From astronomy we find the east, west, south, and north, as well... more
Roman architect Marcus Vitruvius Pollio (c. 75-15 BC) wrote, “[O]ne who professes himself as an architect should be…acquainted with astronomy and the theory of the heavens…. From astronomy we find the east, west, south, and north, as well as the theory of the heavens, the equinox, solstice and courses of the stars.” (De Architectura Libri Decem I:i:3,10).  In order to investigate the role of astronomy in Graeco-Roman  architecture, the author conducted a preliminary GIS DEM/Satellite Imaging survey of 11 temples at Pompeii, Italy (N 40d 45', E 14d 29') measuring the elevation, true azimuth and horizon altitude of each temple’s major axis. The alignment data was field checked by a Ground Truth survey with theodolite and GPS, 7-18 April 2013.  The field data was analyzed with Program STONEHENGE (Hawkins 1983, 328-330) to identify the local skyline declinations in antiquity.  Although the major axes of three temples (Apollo, Jupiter and Venus) parallel Pompeii’s street grid (oriented on Mt. Vesuvius to optimize urban sewer/street drainage), all 11 temples are oriented to astronomical targets on the local horizon associated with Graeco-Roman agricultural/civil/maritime calendars, mythology and/or Hellenistic temples elsewhere, viz: Arcturus Heliacal Rise (HR) at Equinox; Rigel HR at Summer Solstice; Sargas HR at Winter Solstice; November/February Cross-Quarter Day sunsets; Equinox sunset; Winter Solstice sunset; Midwinter Major Stand Still moonrise; and Midsummer Major Standstill moonset.
New Light on Stonehenge from Ancient Greeks Around 50 BC the Sicilian historian Diodorus described a temple often identified as Stonehenge: … Hecateus [c 350 BC] and certain others say that in the region beyond the land of the... more
New Light on Stonehenge from Ancient Greeks

Around 50 BC the Sicilian historian Diodorus described a temple often identified as Stonehenge:

… Hecateus [c 350 BC] and certain others say that in the region beyond the land of the Celts [Gaul] there lies in the ocean an island no smaller than Sicily. This island… is inhabited by the Hyperboreans… there is also on the island a magnificent sacred precinct of Apollo and a notable temple adorned with many votive offerings and spherical in shape. They also say how the moon viewed from this island appears to be but a little distance from the earth… the god visits the island every 19 years, the period in which the return of the stars [astron] to the same place in the heavens is accomplished; and for this reason the 19-year period is called by the Greeks the year of Meton (Diodorus Siculus, II).

Archaeologists now regard the 56 Aubrey Holes as having held large posts. But why not 57, a multiple of the 19-year period of the Metonic cycle?

The cycle says that if there is a full moon on 21 June, the moon again will be full on 21 June 19 years later, but at a different position on the horizon. If the full moon starts over the Heelstone, for example, it will slowly slip away each 19 year interval. On the other hand, if you count 19, 18 and 19 years (a total of 56), it will stay completely on the stone throughout many cycles. It would seem that the architects of Stonehenge had knowledge of both: there are 19 stones in the bluestone horseshoe and there are 56 holes in the Aubrey circle.

It is not the return of ‘stars’ alone to the same place in the heavens that is marked by the horizon alignments at Stonehenge, but rather of the luminous bodies (astron, άστρον), that is sun, moon and stars. We interpret Diodorus’ words to mean that Stonehenge records the turning points of the midsummer sun and midwinter moon with the seasonal zodiac stars, when all these luminous bodies return to the same place in the Year of the High Moon every 19+18+19 years.

The Roman writer Plutarch (2nd Century AD) provides the evidence to link the number 56 with eclipses, supported indirectly by the ancient myths of cosmic struggles between light and darkness, Greek (Typhon vs Zeus) and Egyptian (Set vs Horus and Osiris):

… [T]he 56-sided polygon is said to belong to Typhon, as Eudoxus [Greek astronomer c 370 BC] has reported… There are some who give the name Typhon to the shadow of the earth, into which they believe the moon falls and so suffers eclipse… which the sun remedies by instantly shining back upon the moon when it has escaped the earth’s shadow (Plutarch, De Iside et Osiride 30,44,55).

The movement of the moon has occupied the lives of many, many astronomers, and there are hundreds of terms to describe it. That the moon undergoes this movement to higher declinations, higher and higher in the sky, and then becomes lower and lower, has come out of the Stonehenge study. In certain places, such as southern Ireland, the moon would disappear behind the mountains. In higher latitudes, it would become circumpolar, never setting – the land of the midnight moon, one could say. The 56-year cycle which controls it was not really understood or mentioned by astronomers. It is something that has come from the past to us – ancient knowledge transferred in a set of alignments.
ABSTRACT: Two ancient Chinese texts, the Chou Bei Suan Ching and Chou Li (Western Han Dynasty, ca. 100 BC), record that the Imperial Astronomer (Feng Hsian Shin) made solar observations to determine the solstices and equinoxes, and for... more
ABSTRACT:  Two ancient Chinese texts, the Chou Bei Suan Ching and Chou Li (Western Han Dynasty, ca. 100 BC), record that the Imperial Astronomer (Feng Hsian Shin) made solar observations to determine the solstices and equinoxes, and for determining the cardinal directions with a circle and gnomon. By combining the techniques of astro-archaeology (G. S. Hawkins, 1968) with both overhead imagery and ground survey, the present study seeks to link historical Chinese descriptions of astronomical phenomena with contemporary architectural orientation. In the process, several unexpected astronomical orientation patterns emerged which apparently do not appear in the surviving historical record. For example, at the imperial Western Han capital of Ch'ang-an (N 34° latitude), the diagonals of cardinally oriented square pyramid mounds (ling) align to zenith (+34° declination) and nadir (-34° declination) star rise and set points on the skyline. This is in accord with the Chou (Zhou) Dynasty's name of Chung-Kuo, meaning Central Country or Middle Kingdom. That is, the imperial capital is centered both politico-geographically with respect to its vassal states of the Eastern Yi, Southern Man, Western Rong, and Northern Di, as well as astro-geomantically regarding the color-coded Five Sacred Directions East-South-West-North-Zenith/Nadir in the Cosmos. Our ground survey also confirmed pyramid orientation to the lunar standstills (+/-28°, +/-18° and +/-5° declination) that we reported from overhead imagery in 1980 (155th AAS Meeting, HAD 18.CE.12, Lunar and Solar Alignments of Ancient Chinese Pyramids). Grateful acknowledgment is given to the Chinese Academy of Sciences for the invitation to conduct an astro-archaeological survey of the Wei-ho valley, Shensi (Shaanxi) Province.
Evidence is presented for a newly discovered set of interior solar alignments - the equinox and summer solstice meridian transits - at a prehistoric Native American structure in the Southeast United States. Because North Carolina's Town... more
Evidence is presented for a newly discovered set of interior solar alignments - the equinox and summer solstice meridian transits - at a prehistoric Native American structure in the Southeast United States. Because North Carolina's Town Creek Indian Mound is the only Mississippian temple-mound accurately reconstructed from overhead photo-mosaics, the site is uniquely suited for applying the techniques of astro-archaeology (G. S. Hawkins 1983). Implications of the new findings for interpreting Muskogean ethnographic literature as well as future archaeoastronomical research at other Southeastern sites (e.g., Ocmulgee National Monument Earth Lodge, Georgia) are discussed.
Three independent converging lines of physical evidence support a preliminary interpretation of Irish Early Christian occupation at the Gungywamp site, Groton, Connecticut: -Calibrated Carbon-14 date to mid 6th century AD.... more
Three independent converging lines of physical evidence support a preliminary interpretation of Irish Early Christian occupation at the Gungywamp site, Groton, Connecticut:

-Calibrated Carbon-14 date to mid 6th century AD.
-Hiberno-Latin "nomina sacra" petroglyphs.
-Calendrically oriented drywall oratory architecture.
ABSTRACT: The Hiberno-Latin literary metaphor of "Xpistus sol verus" (Christ the True Sun) finds an architectural analogue in the orientation of the single eastern window of Irish monastic stone chapels or oratories. The author's field... more
ABSTRACT:  The Hiberno-Latin literary metaphor of "Xpistus sol verus" (Christ the True Sun) finds an architectural analogue in the orientation of the single eastern window of Irish monastic stone chapels or oratories. The author's field surveys in Ireland, Hebrides, Orkney and Shetlands revealed that the window of Irish rectangular dry stone oratories framed the rising solar disk on the Feast Days of selected saints of the Celtic Early Christian Church, AD 800-1100. The most frequent target skyline declinations were to sunrise on the Feast Days of St. Patrick (March 17th) and St. Aidan of Lindisfarne (August 31st). During the Early Christian period, St. Patrick's Day coincided with the Vernal Equinox, and heralded the Paschal Full Moon (i.e., Passover crucifixion) and Easter Sunday as proclaimed by Emperor Constantine at the Council of Nicaea (AD 325). St. Aidan of Lindisfarne (d. AD 651) inspired the Irish monks who, at the Synod of Whitby (AD 664), remained loyal to the Jewish 84-year cycle determining Passover and refused to replace it with the new orthodox 19-year computus for Easter adopted by the Roman Catholic Church (AD 527). Hypothetical affiliation between monastic communities whose oratories share common solar orientation, interior length/width ratios (e.g., 4:3 and 3:2) and units of measurement (e.g., Scottish ell, Coptic cubit, or Roman pes) is discussed. Grateful acknowledgement is made to the Michael D. Coe Fund and Augusta Hazard Fund of Yale University for research grant support in 1999.
The Roman astral-cults of the Sun (Sol) and Moon (Luna) enjoyed imperial sponsorship for 300 years, as evidenced by their images on Roman coinage from the end of the 1 st century (Salzman 1990, p. 150; Clauss 1997, p. 250; Hijmans 2003,... more
The Roman astral-cults of the Sun (Sol) and Moon (Luna) enjoyed imperial sponsorship for 300 years, as evidenced by their images on Roman coinage from the end of the 1 st century (Salzman 1990, p. 150; Clauss 1997, p. 250; Hijmans 2003, p. 383).  However, on the Dies Natalis Invicti, AD 25 December 274, Roman Emperor Aurelian decreed Sol Invictus as the Dominus Imperii Romani, and ordered imperial coins honoring Mithras-Sol Invictus to be minted and the Templum Solis Aureliani to be built in Rome (Figure 1).

    The research focus of this paper study is to investigate the hypothetical role of astronomical orientation of Mithraic temples as a supplement to  traditional approaches to the History of Architecture, e.g., iconography, inscriptions, geometry, literature, and mensuration, (see Scavi et al. 2016).  The present study examines the orientation of four Mithraic temples (mithraea) adjacent to imperial Roman army forts (three on Hadrian’s Wall and one at Dura-Europos, Syria).  The paper presents counter evidence rejecting the claim that the major axes of two  of these mithraea were oriented to the sunrise on the Winter Solstice (December 22nd) or Dies Natalis Invicti (December 25th) (cf. Sparavigna 2017a, 2017b).  Rather, all three known mithraea on Hadrian’s Wall are oriented respectively to the rise of the three brightest stars of constellations represented in the Mithraic bull-slaying tableau (tauroctonos) ca. AD 250, viz.: Aldebaran (α Taurii), Antares (α Scorpii), and Sirius (α Canis Major), thereby independently confirming the astral interpretation of K.B. Stark (1869).  Every 19 years, the Dura-Europos mithraeum in Syria is oriented to the midwinter Full Moon rise at the minor lunar standstill, just as a mithraeum on Hadrian’s Wall is oriented to the Full Moon rise marking the death of Deified Hadrian (July 10th) .
Hawkins 1964 proposed that Stonehenge (TPQ 3000 BCE) was designed as a " Neolithic Computer " to time eclipse danger periods. This paper updates the evidence that the constructions at Stonehenge deliberately incorporated... more
Hawkins 1964 proposed that Stonehenge (TPQ 3000 BCE) was designed as a " Neolithic Computer " to time eclipse danger periods. This paper updates the evidence that the constructions at Stonehenge deliberately incorporated astro-architectural features consistent with serving as an analog computing device to predict eclipses based on local horizon alignments to the solstices (+/- 24° declination) and major lunar standstills (+/-29° declination), as well as digital numerical artifacts designed into the architecture encoding luni-solar cycles, viz.: 19 Bluestone(s) Horseshoe :: 19 year Metonic Cycle; 56 Aubrey Hole(s) Circle and Avenue's gap :: 19 +18+19= 56 year Stonehenge Cycle (where 56/3 = 18.66 is an approximation of Halley's 18.61 year Saros Cycle); 29.5 Sarsen Circle uprights and 29Z & 30Y Holes, 29+30 = 59 Bluestone(s) Circle :: double month averaging the 29.5-day lunar synodic period. An additional numerical artifact is proposed, viz., the 5:12 ratio of the sides of the Station Stone Rectangle was selected from among an infinite number of possible rectangles precisely because each of its twin component 5:12:13 Pythagorean triangles uniquely delineates in space (Area = 30 Ratio Units sq.; Perimeter = 30 Ratio Units), i.e., the integer which most closely approximates in time the moon's synodic period (29.53  days).