Deák Antal András: A háromszögeléstől a Tisza-szabályozásig. (Források a vízügy múltjából 10. Budapest, 1996)

FOREWORD

The third source involved is "Introductio in praxim triangulationis". This book, which can be read in Hungarian for the first time, was published in Latin in 1827. Its author is Pál Vásárhelyi, the engineer of the age of the Reform who hav had more than a decade of practice in the field of triangulation. First he measured the valley of Körös-Berettyó with his colleagues under the direction of Mátyás Huszár. Then he was ordered to measure the Danube from 1823 on. In 1829 he began work there as a head-engineer. The work of Vásárhelyi and his colleagues not only included details of the riverbed, but it also mapped the flood areas. They often did the work of triangulation and levelling in the swamps, and marshes under terrible conditions. The measurement of the Danube, the Körös and the Tisza was a great undertaking, which was remarkable in Europe. There were several thousand maps, vertical and cross sections made. The completed regulation work is the proof of their exceptional ability. The work written about the triangulation gives evidence of a serious theoritical learning. Vásárhelyi studied at Institutum Geometricum founded in 1782, which was the predecessor of the present Technical University. He was a student in the faculty of hydrotechnology, and he became a water engineer. The institut gave degrees to 1141 engineers during 1782-1853. Pál Vásárhelyi was the most important engineering figure of the Hungarian water redirection in the XIX

th century. He died suddenly in 1846, the same year that had been elected as the chief engineer of the Tiszavölgyi Társulat and that the second conquest, the Tisza redirection began.