This article first appeared in my Matrix of Creation website in 2012 which was attacked, though an image had been made. Some of this material appeared in my Lords of Time book.
Gavrinisand Tables des Marchands are very similar monuments, both in the orientation of their passageways and their identical latitude. Gavrinis is about 3900 metres east of Tables des Marchands but, unlike the latter, has a Breton name based upon the root GVR (gower). Both passageways directly express the difference between the winter solstice sunrise and the lunar maximum moonrise to the South, by designing the passages to allow these luminaries to enter at the exact day of the winter solstice or the most southerly moonrise over many lunar orbits, during the moon’s maximum standstill. Thus both the monuments allow the maximum moon along their passageway whilst the winter solstice sunrisecan only glance into their end chambers.
From Howard Crowhurst’s work on multiple squares, we know that this difference in angle is that between a 3-4-5 triangle and the diagonal of a square which is achieved directly by the diagonal of a seven square rectangle.
In my academia.edu paper on lunar simulators, based upon the surviving part of a circular structure at Le Manio (Carnac, Brittany), a very simple but poor approximation to PI could be assumed, of 82/26 (3.154) since there seem to have been 82 stones in the circle and the diameter was 26 of the inter-stone distance of 17 inches. The number 82 is significant to simulation of the moon’s orbit since that orbit is very nearly 27 and one third days long (actually 27.32166 days). In three orbits therefore, there are almost exactly 82 days and in day-inch counting that is 82 day-inches. Also of interest is the fact that in three orbits, the exact figure would be 81.965 day-inches which approaches the megalithic rod of 2.5 MY as 6.8 feet.
Sacred Number and the Lords of Time interpreted Thom’s megalithic fathom of 6.8 feet (as 2.72 feet times 2.5) found at Carnac’s Alignments as a useful number of 82 day-inches between stones in the stone rows of Le Menec. After 82 days, the moon is in almost exactly the same place, amongst the stars, because its orbit of 27.32166 days is nearly 27 and one third days. Three orbits sums to nearly 82 days. But the phase of the moon at that repeated place in the sky will be different.
The three henges appear to align to the three notable manifestations to the north west of the northerly moon setting at maximum standstill. The distance between northern and southern henge entrances could count 3400 days, each 5/8th of a foot (7.5 inches), enabling a “there and back again” counting of the 6800 days (18.618 solar years/ 19.618 eclipse years) between lunar maximum standstills.