The present ditches in the middle of the streets, though they have a perceptible current, and a slight infusion of tequisquite, are an intolerable nuisance, and have a deleterious effect upon the public health. How much more so must they have been when, from the uncleanly habits of the Indians, they were the common receptacle of all kinds of filth, and were constantly stirred up to their very bottoms by the setting-poles of the navigators? The system of canalling is a system of slack-water navigation, but abhors stagnant water.
We come next to the question of the dimensions of these street canals. We know that they were intended only for the navigation of Indian canoes; that two of them, which intersected the causeway of the night retreat, Cortéz crossed with his army, all of them climbing down into the canal, wading across, and then climbing up on the other side while loaded with their armor, and fighting all the time against a superior force of the Aztecs; and that Alvarado actually leaped across one of the openings, shows conclusively that the canals could not have more than equaled in breadth the present canal of Chalco. On the hypothesis that Cortéz used scows that drew no more water than the scows that at present navigate the canals, his story becomes credible, so far, at least, as the possibility of making the circuit of the city in large boats in a season of rains.
TRUTH AGAINST FICTION.
It is an ungracious task to sift truth from fables. One man is displeased at seeing held up as a fiction a narrative which he has been accustomed to read with pleasure, and to take for truth, because it was elegantly written; and he requires an accumulation of proofs and arguments before he will abandon a belief which he has adopted without evidence. Another man, who deals only in matters of fact, is easily convinced, and is annoyed at