Our survey at Le Manio revealed a coherent arc of radial stones, at least five of which were equally long, equally separated and set to a radius of curvature that suggested a common centre. They can be found set into the public walkway at Le Manio, Carnac, Brittany, between the southern kerb of the Quadrilateral and the recent dry stone wall that defines the pathway. This southern kerb has been shown[1] to incorporate a day-inch count for three solar years to its extreme eastern tip [from Point P to Q’ on our plan]. These stones were found to have a centre of curvature at stone 29 of the southern kerb and the arc they suggest would represent, if complete, a circle of 82 similar stones 17 inches apart whilst the radius of curvature was determined to be 221 inches or 13 times 17 inches. This provides a reasonable approximation to 2 times Pi as a ratio 82/13.
The angle of the southern kerb was measured in our survey as being 22.3 degrees north of east, the acute angle in comparison to an east-west line creating the geometry of a right-angled triangle whose two longer sides form the ratio 12.368 to 13.368, an invariant triangle based upon the frequencies of lunar synodic months to lunar sidereal orbits occurring in a solar year. The known day-inch count for three lunar years on the southern kerb is 88.59 feet long which becomes the hypotenuse of a right-angled triangle whose baseline runs east-west and is of length 82 feet. This reveals 82 beneath the fragment of an 82 stone ring as being the length of 36 lunar sidereal orbits in day inches versus the 36 month day-inch count above.
It appears therefore that the astronomers at Le Manio understood that following three lunar sidereal orbits, after 82 days, the moon would appear again at the same point on the ecliptic at the same time of day[2], a very important observational fact and one that would have enabled them to build circular 82-stone circles representing the ecliptic in which a moon marker could be moved by three stones a day, completing an orbit in 27.333 days and returning to the original ‘start’ stone after 82 days had elapsed.
