lves after their own fashion, baking adobes, large mud
bricks, in the sun, and building with them one-storey houses with flat
roofs, much as they do at the present day. And thus a new Mexico,
nearly the same as that we are now exploring, came to be planted in the
midst of the waters. Three centimes have elapsed since; the city has
grown larger, churches, convents, and public buildings have increased,
but the architectural character of the place has scarcely altered. It
is the situation that has changed. The lake of Tezcuco is four miles
off, though the causeways which once connected the city with the dry
land still exist, and have even been enlarged. They look like
railway-embankments crossing the low ground, and serve as dykes when
there is a flood, a casualty which still often happens.

This change is interesting to the student of physical geography; and
Humboldt's account of the causes which have brought it about is full
and explicit. When Mexico had been built a few years, the frightful
inundations which threatened its very existence at length awoke the
Spaniards to a sense of the mistake that had been made in placing
themselves but a few feet above the lowest level of the valley, in such
a way that, from whatever point the flood might come, they were sure to
get the benefit of it. The Spanish authorities at home, with their
usual sagacity, sent over peremptory orders that the city should be
abandoned, and a new capital built at Tacubaya--a proposal something
like intimating to the inhabitants of Naples that their position, at
the foot of Mount Vesuvius, was most dangerous, and that they must
leave it and settle somewhere else. In those days the valley was a
complete basin, with no outlet--at least not one worth mentioning; and
the heavy tropical rains and the melted snow from the mountains, poured
vast quantities of water into it. Had the valley been at the level of
the sea, it would simply have become a great lake, surrounded by hills;
but at three thousand feet higher, the atmosphere is rarefied, and
evaporation goes on with such rapidity as to keep the accumulation of
water in check. So the affair had adjusted itself in this wise, that
the land and the five lakes should divide the valley about equally
between them. It became necessary to alter this state of things, and a
passage was cut at a place where the hills were but little above the
level of the highest lake. The history of this passage, the famous
"Desagu