Archaeoastronomy in the British Isles - The Stones and the Stars: Building Scotland's Newest Megalith - page 80

Leaving the sarcasm aside, the charge of inaccuracy is the nearest
this paragraph gets to detailed argument, and Daniel reiterates it
in his subsequent letter. Isolated errors have been found in the sur-
veys, although taken together they constitute nothing like enough
to invalidate the huge body of the work. Thom's accurate sight-
lines have been challenged by other surveyors, whose methodology
has been challenged in turn by MacKie [ 3 ], and his argument will
be summarized below. First, however, two independent checks on
Thom's approach will be made here.
Thom was a yachtsman, among his many skills, and his inter-
est in ancient astronomy was sparked when at anchor off the island
of Lewis, as he watched the Moon rise over the Callanish stones
(Fig. 4.18 ). The sight aroused his engineer's curiosity. Surely the
relationship he could see couldn't be coincidence?
Many of his surveys of standing stones in the Hebrides were
carried out on his sailing trips, but on the island of Colonsay
(Fig. 4.23a ), in the inner Hebrides, he was able to make only “a
very preliminary survey” because, the night after he arrived, a
storm had come up, and his yacht's anchor began to drag. He had
to sail off for safety, and the opportunity to return to the island
had never arisen. This provided an excellent chance to investigate
a set of stones not included in Thom's published surveys, and as
part of the Glasgow Parks Astronomy Project, visits were made
to Colonsay in 1978 and 1979, with a follow-up in 1980. Even on
that one small island, the more stones visited, the more came to
light. The Manpower Services Commission agreed to send a sur-
vey team over in 1979, but other commitments made that impos-
sible to carry out.
Nevertheless, even rough bearings with compass and clinom-
eter were enough to show that, where the stones had horizon sight-
lines, some at least were astronomically significant. For example,
the standing stone above the hotel at Scalisaig, on the edge of a
small circle, appears to have a top shaped to match a notch on the
skyline, to a sea horizon, pointing to midwinter sunset (Fig. 4.23b ) .
When that was checked later against the Professor's “preliminary
survey,” courtesy of Archie Thom, he had identified the same
bearing with far greater accuracy.
However, the small circle of stones at the base of the large one
suggested a fire site, and that led to finding the possible remains of