"from described by Bratth in his 'Laws of Desert formations', i.e. with a hollow crescent in front we should the sand falls. Shortly after this, after 4 P.M., a little over 12 Las Vegas are arrived at the edge of the upper plain where there is a deep cut or deep 'barancha's' to the next lower level. Just before arriving then we noticed that alluvial rising from the ground and are some bars that they came from the deep barancha but did not show of remains of their banks. Down which are some to have a grand oasis. The field is said to be 120, meters deep and the other height composed of leaves and tails. At one place I noticed a small oak grown stone, coming to the edge as the plunge over an over rolled down into the barancha. I understand that this is the condition all along the eastern slope of Mexico's. The higher plain runs out by jungle with their outer edges dropping constantly down and lower. The flow of the ayin in this of the high volcanos i.e one consisting of small emplacements. Their mouths are in the ayin. Where the flat lands hit a far miles over but after it changes abruptly in one of a rock condition, hard sorts come in and