Nam flumen, quo latius fusum est, hoc placidius stagnat; quippe angustis ripis coercita et in angustiorem alveum elisa torrentes aquas invehunt,  contra spatio alvei segnior cursus est.
Indeed, the wider the extent of a river, the more quietly it flows; for when restrained by banks that are close together, and hence dashed into a narrower channel, they carry torrential waters, and on the contrary their course is more sluggish in a spacious  channel.
final_alignments\Quintus_Curtius_Alexander_Book9.json