It is a remarkable fact that every River Valley which I have ascended <lb xmlns="http://www.tei-c.org/ns/1.0" />opens out & becomes broad & flat-floored, at about <measure xmlns="http://www.tei-c.org/ns/1.0" quantity="10000" unit="foot">10,000 feet</measure>: it <lb xmlns="http://www.tei-c.org/ns/1.0" />becomes imper<subst xmlns="http://www.tei-c.org/ns/1.0"> <del rendition="#ow">f</del> <add place="across">c</add> </subst>eptibly more & more so as you ascend; & when it has <lb xmlns="http://www.tei-c.org/ns/1.0" />conducted you above the limits of clouds, rain & snow, it gradually <lb xmlns="http://www.tei-c.org/ns/1.0" />becomes drier, barren & more Thibetan.