Archaeoastronomy in the British Isles - The Stones and the Stars: Building Scotland's Newest Megalith - page 83

F IG . 4.23 (Continued)
However, MacKie writes
[S]ince the late 1970s Clive Ruggles has systematically and
skillfully questioned Thom's astronomical work, starting with
a reassessment of 300 of his claimed long celestial alignments
on Scottish west coast and in the Western Isles. The conclu-
sion of this critique was that there was no real evidence either
for extreme accuracy or for the use of a detailed solar calen-
dar in Neolithic times (broadly the period 4000-2000 b.c.)….