The economic and financial unit of the nation being thus defined, it was also provided that a national census should be returned at a fixed period. New taxes were of three kinds, the principal one, called _so_, being levied upon land. The method of its assessment was to fix the annual produce of two _tan_ of rice land at 100 sheaves, 8 of which--4 large and 4 small--were taken as tax, or, roughly, five per cent. of the gross produce. Of the other two kinds of taxes one was called _yō_ and the other _chō_. The former may be regarded as a species of _corvée_. After a man attained the age of twenty-one he was required to perform ten days' public work annually, which service, however, he was at liberty to commute for one piece of cloth (_nuno_). The _chō_ was levied on silk, fish, cloth, and generally speaking on objects produced or obtained in considerable quantities. The proceeds of the rice-tax were applied to defray the expenses of local administration, while the outlay of the central government was met by the proceeds of the two other taxes, _yō_ and _chō_. As regards local administration, the old names of local divisions, _kuni_ (provinces) and _kōri_ (districts), were retained, while towns, _sato_, were organized generally by grouping together fifty houses under a town-head. Along the principal roads relays of post horses were maintained for public service, and every person traveling in the interior was required by law to carry a hand-bell and a document similar to a passport. At important places guard-houses were established, with duly appointed lookouts and garrisons for preserving order. Government business was transacted in the provinces under the control of officials collectively called _kokushi_, and in the districts under that of _gunshi_. The former set of officers were appointed by the central government from among the nobler families, while the latter seem to have been largely supplied by the descendants of old local magnates. In those days the empire comprised 58 _kuni_, over 500 _kōri_, and about 13,000 _sato_, but subsequent changes resulted in 66 _kuni_ and more than 700 _kōri_, which numbers continued till the beginning of the present reign.