Robert Munro,
1911 Encyclopædia Britannica
(1911)
“ The societies advised that trilithon 6, 7, with lintel—which had slewed round—and trilithon 56, which was leaning at a dangerous angle, should be examined with a view to replacement with as little excavation as possible; that the monolith and lintel 22 be replaced, and its companion sarsen (21) secured; and that trilithon 57, 58, should be re-erected in its place, which was exactly known. Steps were taken to place the matter in the hands of engineering experts. On the 19th of September 1901 trilithon 56 was successfully raised to a perpendicular position. ”
