Note 142 — Chapter XX · ACROSS THE CONTINENT TO MENDOZA UNDER THE ANDES

"When one hears of a natural bridge, one pictures to oneself some deep and narrow ravine, across which a bold mass of rock has fallen; or a great arch hollowed out like the vault of a cavern. Instead of this, the Inca's Bridge consists of a crust of stratified shingle, cemented together by the deposits of the neighbouring hot-springs. It appears as if the stream had scooped out a channel on one side, leaving an overhanging ledge, which was met by earth and stones falling down from the opposite cliff. Certainly an oblique junction, as would happen in such a case, was very distinct on one side. The Bridge of the Incas is by no means worthy of the great monarchs whose name it bears" (Darwin, "Voyage of the Beagle," chap. xv.). [142]