Deák Antal András: A Duna fölfedezése
Tartalom - III.A DANUBIUS PANNONICO-MYSICUS, 1726
T II E DISCOVERY OF THE DANUBE He arranged the measurement values in charts by month and day, the hour, the value read from the thermometer, the value read from the barometer, the shape of the snowflakes, the degree of frost, the wind direction, the brightness of the sun, the clouds, snow or rain. Until the 28 t h of December, the chart is amply illustrated with drawings, the degree of frost is marked by the symbols 0, 00, 000, which indicated slight, temperate and strong frost. He started to register the temperature readings from the thermometers only on the 24 t h of January 1697. From the 29 t h of December he no longer indicated the degree of frost except for three days (January 6, 7 and 9), the drawings of snowflakes, clouds and the sun disappeared, while he described the direction of the wind and other weather conditions under the heading of air quality, which contained only written information. This assortment of many pieces of data allowed him to recognise the connections between them. Using the charts, he summed up the results which he divided into three groups in ten pages. First, he examined the characteristics of his barometer measurements from December 1696 to August 1697. He found that when the barometer was placed in the south it showed more than the double the value read from the barometer placed in the north in winter and in spring until 8 May, while the results were just the opposite from the 21 s t of May to the 30 t h of August. He explained the phenomenon as the result of a defective instrument. 29 6 Then he surveyed the values the barometer showed when it snowed, the sun shone or when there were clouds in the sky. Finally, he discussed the conclusion he drew from the values indicated by the thermometer. He perceived connections but could not always explain them. A mystery he could not solve was e. g. why the barometer reacted differently in subsequent seasons. Regarding the connection between the cold and the wind he thought that that the degree of cold did not depend on the wind. Finally, he arrived at an interesting conclusion concerning comparison of the values read from the thermometers and the barometers. He realised that the connection between the changes in temperature and atmospheric pressure was that when the atmospheric pressure increases the temperature sinks and vice versa. The volume closed with a description of the insects living along the Danube and the Tisza. He mentions in the introduction that he was especially interested in the question of the reproduction of insects. It was the phenomena he experienced in the military camps that aroused his interest. Clouds of mosquitoes made life unbearable in the vicinity of swamps. Epidemics raged during sieges. He mentioned the siege of Buda because of the rotting corpses. And with favourable weather conditions, the earth became an ideal nest for locust eggs, which ended in locust invasions. He noticed that worms also laid eggs and rotting organisms served as their breeding ground. There they multiplied and infested living organisms by inhalation or through the water during washing or from the vessels used for eating and drinking. The observations made during the dissection of an eagle, which feeds on carrion as well, supported his theory. His knowledge proved useful during epidemics and he rescued the lives of people by taking strict preventive measures in the military camps: the sick people were isolated, and the people who had come from infected territories were quarantined. He even forbade acceptance of customary gifts from the Turkish negotiating delegation if their camp had been contaminated by an epidemic. 297 Following the usual introductory thoughts, he listed the insect species in a comprehensive chart, then described the terrestrial species (dipterous, hymenopterous, apterous insects and arthropods), those that live near the water and finally those that live in water IMAGE No. 47 on page 84: Marsigli used a microscope to examine insects living along the waters 29 6 In the opinion of Lajos Bartha this was probably caused by a fault in one of his instruments. 29 7 Katalin Kapronczay: The legacy of L. F. Marsigli's manuscript writings on medical topics = Lecture at MTESZ on the 21 November 2001. 155
