Archaeoastronomy in the British Isles - The Stones and the Stars: Building Scotland's Newest Megalith - page 81

F IG . 4.23 ( a ) The island of Colonsay, inner Hebrides (After Frances Walker,
1970s). ( b ) Scalisaig standing stones, island of Colonsay, from upslope. The
skyline notch behind contains a sea horizon with an altitude of −1° 30 ¢
(Photo by author, 1976). ( c ) Alignments of some standing stones on Colon-
say. ( d ) Key to Fig. 4.23c alignments
two similar sites on a small hilltop and a slope to the east - both of
them with prominent horizon notches, and all apparently significant
(Fig. 4.23c, d ). The accuracy is at least as good as Hawkins's plus-
or-minus 2° in Stonehenge Decoded , and it's quite probable that a
proper survey would show the accuracy found elsewhere by Thom.