Note 17 — Chapter VIII · NORTHERN CHILE.—CONCLUSION. (continued 2)

I have endeavoured to show in my “Journal” (2nd edit., p. 321), that the singular fact of the river, which drains the valley between these two ranges, passing through the Portillo and higher line, is explained by its slow and subsequent elevation. There are many analogous cases in the drainage of rivers: see Edinburgh New Phil. Journal, vol. xxviii, pp. 33 and 44.