Deák Antal András: A Duna fölfedezése
Tartalom - III.A DANUBIUS PANNONICO-MYSICUS, 1726
T II E DISCOVERY OF THE DANUBE astronomic observations at a distance, methodically teaching Marsigli through letters. He purchased Riccioli's book as well. 256 It was perhaps the confusing atmosphere of military life that contributed to his decision to charge J. C. Müller, a young man adept in the use of a quadrant, with making most of the observations. Naturally, he himself also made observations. In 1699, for example, during the demarcation of the frontiers, he observed the eclipse of the sun on the banks of the Corana river in Lower Croatia. Nearly all the Turks swarmed out from their tents, he wrote, to see the observation being made, so miraculous in their eyes, since I was doing something that nobody had ever seen done in their country. 25 7 Marsigli himself was not satisfied with the exactitude of his measurements. Luckily, Cassini was against his destroying the measurements, on the contrary, he insisted that even if, in Marsigli's words, the Danubiale Opus would never appear, he should edit them separately, since such measurements had never before been made in Hungary 25 8, and because, on the other hand, this work could not be expected from any of the armchair scientists who operated free from any kind of disturbing circumstances. Examining Marsigli's above-mentioned latitude measurement results we can see that the distortions of the map were caused not so much by the inaccuracy of the measurements as by their low numbers: The chart reveals that these measurements occasionally diverged from the modern values but by no more than a few minutes. Furthermore, they were certainly much more accurate than other contemporary latitude measurements. 25 9 The geographical position of Vienna given by Marsigli 48° 14' today 48° 12" The geographical position of Buda given by Marsigli 47° 24' today 47° 29" The geographical position of Baja given by Marsigli 46° 10' today 46° 10" The geographical position of the Dráva mouth given by Marsigli 45° 36' today 45°33" The geographical position of Szeged given by Marsigli 46° 16' today 46° 16" Geographical position near Titel in the military camp 45°20" The geographical position of Szolnok given by Marsigli 47° 9' today 47° 10" The geographical position of Eger given by Marsigli 48° 0' today 47°53" 25 6 Riccioli (Joh. Bapt.) Geographiae et Hydrographiae reformatae, nuper recognita et aucta libri XII. 1672. 691 pp. „It should be mentioned that the values of the refraction of atmospheric rays subtracted from the local high points were borrowed from Riccioli. He, of course, observed the same on the horizon of Bologna. (Vol. I. Pars II.) 25 7 DPM Vol. I. Pars II. Introduction. 25 8 Cassini was wrong since latitude had been measured in a few places for Wolfgang Lazius's map; it is certain that instrumental measurements were made in Nagyszombat in the 1670's. Cassini could not have known about them and nor could, regrettably, have Marsigli (Lajos Bartha's oral communication). 25 9 Bartha Lajos: Magyarország első tervszerű felmérésének 300. évfordulójára (The 300 t 8 anniversery of the first planned measurements in Hungary - manuscript). 139
