The Republic Hydrometeorological Institute of Serbia (, ) is the national meteorological and hydrological service of Serbia. Origin Pre-institute weather tracking First "meteorologists" in Serbia were the medieval church and monastery chroniclers who wrote about the weather occurrences which they observed. Scholar Ljubomir Stojanović compiled old manuscripts and arranged them in 7 volumes under the umbrella title Old Serbian records and inscriptions, which were published by the Serbian Royal Academy from 1902 to 1927 as part of its edition Collection for history, language and literature. Meteorologist and geographer Pavle Vujević used these, so as several other books, to extract all the weather data and published them in 1931 work Historical documents about the variations of the climate on the territory of the Kingdom of Yugoslavia. He covered the period from 1358 to 1864, when the meteorology already began the instrumental monitoring of the weather in Serbia. Vladimir Jakšić's meteo-grid Vladimir Jakšić, then only a clerk in the Ministry of Finance and later a professor at the Belgrade Lyceum, on his own accord set a weather station in the backyard of his house in Belgrade's neighborhood of Senjak. He began daily measurements from 1 January 1848, and continued until his death in 1899. He was observing the weather and writing down the temperature, humidity, precipitations, wind speed and atmospheric pressure and his work became the foundation of the meteorology development in Serbia. Already by 1851, Jakšić was able to write first study on the climate of Belgrade. He also left important data on the fluctuation of the water level in the Sava river. In 1856, further weather stations were set in 20 cities across Serbia, while in 1857 that number grew to 27. The grid, still only a private, individual enterprise, was the most dense meteorological grid in Europe at the time. However, Jaksić in 1863 accepted a job at the Ministry of Finance where he founded a Department of Statistics. From that moment the number of meteorological stations began to decrease rapidly. The only weather station which survived was the first, in the Jakšić's backyard. Old observatory In 1879, Milan Nedeljković received a scholarship to continue his education in Paris at the Sorbonne. He studied mathematics and at the College de France extraordinary studying physics. In Paris Observatory the first School of Astronomy was formed, which Nedeljkovic successfully completed. During the study he also finished courses in meteorology, precision mechanics