The exchanges were conducted partly by barter, but more usually in the currency of the country. This consisted of bits of tin stamped with a character like a [Illustration: sans-serif T], bags of cacao, the value of which was regulated by their size, and, lastly, quills filled with gold dust.[366] Gold was part of the regular currency, it seems, in both hemispheres. In their dealings it is singular that they should have had no knowledge of scales and weights. The quantity was determined by measure and number.[367] The most perfect order reigned throughout this vast assembly. Officers patrolled the square, whose business it was to keep the peace, to collect the duties imposed on the different articles of merchandise, to see that no false measures or fraud of any kind were used, and to bring offenders at once to justice. A court of twelve judges sat in one part of the _tianguez_, clothed with those ample and summary powers which in despotic countries are often delegated even to petty tribunals. The extreme severity with which they exercised these powers, in more than one instance, proves that they were not a dead letter.[368] The _tianguez_ of Mexico was naturally an object of great interest, as well as wonder, to the Spaniards. For in it they saw converged into one focus, as it were, all the rays of civilization scattered throughout the land. Here they beheld the various evidences of mechanical skill, of domestic industry, the multiplied resources, of whatever kind, within the compass of the natives. It could not fail to impress them with high ideas of the magnitude of these resources, as well as of the commercial activity and social subordination by which the whole community was knit together; and their admiration is fully evinced by the minuteness and energy of their descriptions.[369] From this bustling scene the Spaniards took their way to the great _teocalli_, in the neighborhood of their own quarters. It covered, with the subordinate edifices, as the reader has already seen, the large tract of ground now occupied by the cathedral, part of the market-place, and some of the adjoining streets.[370] It was the spot which had been consecrated to the same object, probably, ever since the foundation of the city. The present building, however, was of no great antiquity, having been constructed by Ahuitzotl, who celebrated its dedication, in 1486, by that hecatomb of victims of which such incredible reports are to be found in the chronicles.[371]