Vízügyi Közlemények, 1932 (14. évfolyam)

2. füzet - XII. Kisebb közlemények

28 cannot be evaded under the pretext that the owner of the object cannot be included among those who have the benefit of it ; for every such object has a disturbing effect on the conditions of downflow, wherefore the owner is responsible. The measure of the obligation arising from the 40th paragraph may be the area found by multiplying the width of the valley and the length of the object, the latter including also the width of the embankment occupied by the wing walls of the object. The writer deals in detail with the apron works which, as a rule, it is necessary to place below the object, and with the incidence of their construction costs. Finally, on the basis of conditions in Hungary and in connection with damages that may be caused by such old-established objects, he discusses the questions which are to be solved as to the waters from slopes affecting the maintenance of water courses, and the condition of valley streams dependent on the management of waters from slopes. V. AGRICULTURAL ENGINEERING ACTIVITY IN CZECHOSLOVAKIA. By : LEÓ VAS. Agricultural engineering service in pre-war Bohemia was started somewhat latei than in Hungary, yet it shows considerable success. Reclamation works for the purpose of assuring the most economical form of exploitation are carried out with the cooperation of a Research Institute serving for this special object. This Institute prepares detailed instructions for works of subsoil drainage, irrigation, torrent improvement, and bank protection, as well as for reclamation works on the basis of extensive studies and experiences obtained in experimental plants. The investigations extend to questions of meteorology, climatology, pedology and hydrology, as well as to problems of agricultural engineering. This Institute has not yet been long enough at work to have produced results which can be considered as definite, but it has undoubtedly very useful from both the theoretical and the practical point of view. For subsoil drainage, it has solved the question of the distance and depth of tile conduits, and has tabulated these data for different crops and soils. The question of spray irrigation has also been studied in connection with different methods of manuring. The writer of this article finally summarizes the results of the activity of the agricultural engineering service, as based upon these investigations. VI. LATEST FORM OF THE BEAR TRAP DAM. By : JÓZSEF MANTUANO. The writer first outlines the history of the development of bear trap dams, and then describes in detail the Huber and Lutz gate, which is at present most widely accepted ; he especially discusses the question as to the form and dimensions which best allow free motion to the leaves (Fig. 3). He determines the forces acting on the leaves (Fig. 4), and the conditions of equilibrium in a raised position of the gate, first postulating that the connecting chain is loose and that the curvature of the downstream leaf may be left out of consideration (Fig. 5). The writer