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.
Figure 1 The three henges are of similar size and design, a design most clear in what remains of the central henge. [photo: Iain Petrie]
Only two type-D stone circles (see figure 3) are
known to exist, called Roughtor (in Cornwall) and Seascale (in Cumbria). Seascale
is assessed below, for the potential this type of flattened circle had to
provide megalithic astronomers with a calendrical observatory. Seascale could also
have modelled the harmonic ratios of the visible outer planets relative to the
lunar year. Flattened to the north, Seascale now faces Sellafield nuclear
reprocessing plant (figure 1).
Figure 1 Seascale type-D flattened circle and neighbouring nuclear facility. photo: Barry Teague
Stone Age astronomical monuments went through a
series of evolutionary phases: in Britain c. 3000 BC, stone circles became
widespread until the Late Bronze Age c. 1500 BC. These stone circles manifest
aspects of Late Stone Age art (10,000 – 4500 BC) seen in some of its geometrical
and symbolic forms, in particular as calendrical day tallies scored on bones.
In pre-literate societies, visual art takes on an objective technical function,
especially when focussed upon time and the cyclic phenomena observed within
time. The precedent for Britain’s stone circle culture is that of Brittany,
around Carnac in the south, from where Megalithic Ireland, England and Wales probably
got their own megalithic culture.