A benchmark is geographic point whose elevation has been measured and recorded to a high level of accuracy. The height of a benchmark is calculated relative to the heights of nearby benchmarks in a network extending from a fundamental benchmark (a point which records a height to extreme accuracy.) Benchmarks are used by such professionals as surveyors, engineers, and map makers.
In 1880-1888, the Department of Geodesy of the Lviv Polytechnic created the first leveling network in Lviv consisting of 18 benchmarks. The network was used for the construction of Lviv’s first sewer. (The Galicia state leveling network was created by the Military Geographical Institute in Vienna between 1888 and 1892.)
Lviv’s fundamental benchmark was installed on the wall of the main building of the Lviv Polytechnic in 1880 by famous astronomical surveyor, rector of the Lviv Polytechnic, Professor Dominik Zbrozhek. The height was determined by barometric surveying from the level of the Adriatic Sea with the help of a highly skilled international commission.
Here is the first benchmark with a plaque in honor of Dominik Zbrozhek.
“Z. W.” stands for “znak wysokosci,” which is Polish for “height marker.”
а – brass frustum in the wall;
б – iron plate labeled Z. W. (Znak wysokosci);
в – modern look.
Benchmarks were often located on churches and other public buildings. Only a handful of the original 18 benchmarks are still visible in Lviv’s landscape. The rest are either under plaster or have been removed.
I have found a few of the original benchmarks (in addition to the one on the university), as well as the place where one used to be.
The next batch of benchmarks (or so I am guessing, and I am also guessing they were installed during Austrian times) are round and also have the initials “Z. W.” One is on the former Church of Our Lady of Perpetual Help, another is on a building that I believe was some sort of governmental building (as there is Lviv coat of arms on it), and the third one is on the old Lychakiv train station (built in 1906, rail line has been closed for decades).
My guess is that the third batch of benchmarks was the small circular metal ones with numbers, which are still found on many on buildings in Lviv. I beieve these were also from the pre-Soviet era.
Then there are a few different kinds from the Soviet era. These generally have some sort of letters (abbreviations) and often numbers as well.
УКР ГИИНТИЗ (UKR GIINTIZ) = Russian abbreviation for Ukrainian Geological-Engineering and Technical Surveying. (For example, a GIINTIZ institute would include the subjects geology, geodesy, geophysics.)
ПОЛИГ (POLIG) = short for “polygonometry” – method of establishing geodetic networks
ГУГК (GUGK) = the Head Office of Geodesy and Cartography
3072 = number of the marker in the registry with the geodesic description of its location
See also: German-Language Benchmark in Lviv