Megalithic yard

The proposal was made by Alexander Thom as a result of his surveys of 600 megalithic sites in England, Scotland, Wales and Brittany.

Keith Critchlow suggested this may have shrunk 0.63 inches (1.6 cm) from its original length of one megalithic yard over a period of 3000 years.

[11] Thom made a comparison of his megalithic yard with the Spanish vara, the pre-metric measurement of Iberia, whose length was 2.7425 feet (0.8359 m).

[15] Anne Macaulay[16] reported that the megalithic rod is equal in length to the Greek fathom of (2.072 metres (6.80 ft))[15] from studies by Eric Fernie of the Metrological Relief in the Ashmolean Museum, Oxford.

The main weakness in this argument is probably that, in order to derive their yard, the builders of the megalithic monuments would have needed the remen and royal cubit, upon which this geometrical relationship relies.

However, since the megalithic constructs of the British Isles and northern France predate the pyramids by millennia, this supposed counter-argument is anachronistic.

Recent work by John Michell (Ancient Metrology, The Lost Science of Measuring the Earth), John Neal (All Done with Mirrors), Richard and Robin Heath (various works on British megalithic circles and on Carnac) make a case for the connection of the megalithic yard with a systemic relation of geodetics and the lunation cycle.