Geodetic mark located on the minaret of the mosque in Caesarea, Israel
Today, a
few words about special metal details that we can find on historic buildings
(and not only). Survey benchmark is a permanently stabilized point of geodetic
network. They are used for geodetic measurements. In the past they used to be
placed on old buildings, like churches - the best were already stabilized
facilities that completed the settlement process. Many of these marks are so
old that already can be recognized as monuments. Some of them can still be used
as a part of contemporary geodetic network, some of them left only as
historical curiosity. These details are often forgotten when renovating
historic buildings. They are often thoughtlessly covered with paint but we
should keep them and expose as integral part of the buildings' history.
Location of historic geodetic mark on Wrocław cathedral
Geodetic marks - Płock cathedral and Wrocław cathedral
Sometimes
we can also observe new local measurement points on historic buildings, which are used to check whether a given object is moving, e.g. as a
result of construction works carried out nearby.
Contemporary geodetic mark on St. Adalbert's church in Wrocław