HYDRAULICS AND HYDROLOGY IN A PASSAGE OF THE <i>KIT?B AL-???R AL-B?QIYA</i> BY AL-B?R?N?

Abstract The authors translate and comment a digression from the Kit?b al-???r al-b?qiya on several hydraulic hydrological subjects. passage reveals al-B?r?n?’s understanding of fluvial regimes, water physical behaviour, handful peculiar natural phenomena. Al-B?r?n? departs discussion weather forecast seasonal regimes Tigris, Euphrates, Oxus, Nile. main concern al-B?r?n? is to defend principle that moves only downwards in absence external forces. In doing so, Khwarazmian scientist touches origin salinity seas, functioning syphons related machines, relates report an artificial phenomenon, he dismisses as result faulty observations, could be recognised jump. addition, contains much relevant information inhabitability subequatorial regions, possibility void, cycle.