But let us observe the course of the rivers; while confined by the ridges of the Andes and Cordeliers; they run either south or north, and are thus for some time constrained to take a course very different from that which they are afterwards to pursue. It is while thus retained within the ridges of the Andes that those rivers water plains which they had formed; and it is here that we find countries so much elevated above the rest of the world, that, under the direct rays of the sun, their inhabitants are made to suffer from the cold. It is the collection of those waters running from south to north, and descending from an enormous height, that have formed in the plain those appearances that struck so much the French philosopher, as to make him give us a detail, which, though out of his line, is extremely interesting in the natural history of the earth. It is in the valley of the Madelena that M. Bouguer found those grand relicts of the wasted strata; but we are now to take a view of a country situated high above the level of that valley. It is that of Santa Fée de Bogota; a fertile plain estimated at 1600 toises, almost about two miles above the level of the sea; and which pours its water into the valley of the Madelena about a degree above Honda, which is mentioned by M. Bouguer as giving so fine an example of those water-worn rocks. The extreme singularity in the situation of this country, and at the same time the perfect similarity which is here to be observed of this country with all the rest of the earth, as the work of water, will excuse my transcribing from M. le Blond, _(Journal de Physique,_ Mai 1786) what I judge to be interesting to my readers. «Si un observateur attentif parcourt les plaines immenses de l'Amérique méridionale, s'il monte les fleuves rapides et profonds qui les traversent, et les inondent, et s'il franchit les montagnes prodigieuses que l'action des eaux détruit, il apercevra bientôt qu'un développement successif et inévitable de ce nouveau continent tend à l'agrandir dans tous les sens, et rendra peut-être un jour sa surface égale à celle de notre hémisphère.