In a strict military sense the capital of Mexico cannot be called a fortified city. Still, it has defences, one being an _enceinte_ wall, which envelops it all round, leaving no straggled suburb, scarce so much as a house, outside. Compact and close stand the dwellings of the modern city as those of ancient Tenochtitlan, whose site it occupies, though the waves of Tezcuco and Xochimilco no longer lap up to its walls. The _enceinte_ spoken of is a mere structure of "adobes," large sun-baked blocks of mud and straw--in short, the bricks of the Egyptians, whose making so vexed Moses and the Israelites. Here and there may be seen a little redoubt, with a battery of guns in it; but only on revolutionary occasions--the wall, so far as defence goes, more concerning the smuggler than the soldier; and less contraband from abroad than infringement of certain regulations of home commerce--chief of them the tax called "alcabala," corresponding to the _octroi_ of France, and the _corvee_ of some other European countries. The tax is collected at the "garitas," of which there is one on every road leading out of the city, or rather into it; for it is the man who enters, not he making exit, who is called upon to contribute to the _alcabala_. It is levied on every article or commodity brought from the country in search of a city market. Nothing escapes it; the produce of farm and garden, field and forest--all have to pay toll at the _garitas_, so losing a considerable percentage of their value. The brown aboriginal, his "burro" laden with charcoal, or skins of _pulque_, or himself staggering under a load of planks heavy enough to weigh down a donkey, which he has transported from a mountain forest--ten or twenty miles it may be--is mulcted in this blackmail before he can pass through a _garita_. Not unfrequently he is unable to meet the demand till he have made sale of the taxed commodity. On such occasions he hypothecates his hat, or _frezada_, leaving it at the gate, and going on bareheaded or bare-shouldered to the market, to redeem the pawned article on return.