In the early 20th century they had fallen down and were fragmented and covered by vines.
In 1946 a restoration of the pillars was undertaken, directed by UNC professor Thomas F. Hickerson
with the assistance of Archibald Henderson
and R. D. W. Connor
. A new foundation for the pillars, which were about a foot and a half square by about six feet high, were laid on the spaces where they originally stood. They were reportedly repaired in such a manner that the appearance of the old brick wall was changed as little as possible.
From Some Beginnings in Science
, by Collier Cobb
. (Popular Science Monthly, Volume 49, October 1896):
"Dr. Caldwell also built in his garden, where they still stand, two pillars of brick, that their eastern and western faces, carefully ground into the same plane, might mark the true meridian. Near these pillars stood a stone pillar, some five feet high, bearing upon its top a sundial for marking the hours of the day."
From Kemp P. Battle's History of the University (1901):
“President Caldwell...erected in his garden a sun dial, which stood until the invasion of the Federal cavalry. He also built two pillars, still standing, covered with vines, their eastern and western faces accurately showing the north and south line in his day.”