Soon after the completion of the Monument on Fish Street Hill, by Wren,
in 1677, it was used by Hooke and other members of the Royal Society
for astronomical purposes, but abandoned on account of the vibrations
being too great for the nicety required in their observations. Hence
arose _the report that the Monument was unsafe_, which has been revived
in our time; “but,” says Elmes, “its scientific construction may bid
defiance to the attacks of all but earthquakes for centuries to come.”
This vibration in lofty columns is not uncommon. Captain Smythe, in his
_Cycle of Celestial Objects_, tells us, that when taking observations
on the summit of Pompey’s Pillar, near Alexandria, the mercury was
sensibly affected by tremor, although the pillar is a solid.
Geology and Paleontology.