Events: Don't miss the Megalithomania Conference, Glastonbury, 6th/7th May 2006

Oh, OK - sure, here it is:

A really interesting two days - and a deluge of new information, most of which I'm still trying to assimilate.

Here are the high points from my perspective.

John Michell

Well, he's one of the ones who kicked off the resurgence of research into archaeoastronomy/sacred geometry/ancient measurements, and it was a pleasure to meet him. He was kind enough to take a look at my proof of the vesica piscis angle, and confirmed that the error had been corrected ages ago. That's the trouble with owning early editions of books, I guess :-)

His lecture was about the megaliths of West Penwith, Cornwall, and his archive of pictures of them are probably some of the few remaining records of the positioning of some of them.

"The Measure of Albion" - co-authored with Robin Heath - is the first one of the books I bought that I'm reading. This deals with some astonishing geometry in the landscape of Britain, including the 5:12:13 triangle that connects Stonehenge, Lundy Island and the Preseli Hill site of the bluestones used in Stonehenge's construction.

Robin Heath and John Neal

Robin's talk was on Alexander Thom (proposer of the megalithic yard as a standard unit of measure) - he's Thom's biographer, now that's going to be an interesting book when it's published - and showed hitherto unseen photos of his life.

Equally fascinating was the insight into Robin's recent research work with astronomical alignments in west Wales. He's in the process of establishing an MA in Archaeoastronomy and Landscape at St Davids University, Lampeter, involving practical training in the surveying techniques and equipment involved. Naturally, I now want a theodolite and a sabbatical ;-)

John has managed to achieve a unique understanding of the inter-related measurement units of the ancient world - the scope of which is staggering and I couldn't possibly do it justice in a brief summary. Prof. Michael Vickers of Jesus College Oxford has had a go though - here's an extract:

Elaborating on a scheme first noted by John Michell, Neal observes that feet (or cubits) stand in a ratio of 175:176 to larger units in a series. This at once explains Vitruvius' account of an odometer that contained a mechanism designed audibly to release a stone into a box every mile, in this case 400 revolutions of the 12½-ft perimeter wheel to the 5000-ft mile. If Vitruvius' 4-ft radius to 12½-ft perimeter, or 3.125 π ratio was strictly adhered to, there would have been a discrepancy of more than 28-ft in every mile, but if the shorter Roman foot of .96768-ft was used for the diameter of the carriage wheel, and the longer Roman foot of .9732096-ft was used for the perimeter, the calculation of the mile is accurate in terms of the longer measure. The difference between 22/7 and 25/8 can be expressed as 3.142857 = 176, and 3.125 = 175 (both values of pi were used in the ancient world). Neal notes that if a diameter is a multiple of either four or eight, 3.125 may be accurately used to maintain an integral number in the perimeter, as the ratio between using true pi as the module of measurement of the diameter is the 175th part less than that of the perimeter. There was thus a practical purpose underlying variational fractions between the ancient standards (and this is but one of many), and they can no longer be put down to carelessness or error.

I failed to pick up a copy of John's book which contains all his research and conclusions (called "All Done With Mirrors") at the weekend, so that's on order now.

Nicholas Mann