THE third and laft duty of the fovereign or commonwealth is that of erecting and maintaining those public inftitutions and those public works, which, though they may be in the highest degree advantageous to a great fociety, are, however, of fuch a nature, that the profit could never repay the expense to any individual or small number of individuals, and which it therefore cannot be expected that any individual or small VOL. IV. B number of individuals fhould erect or maintain. The performance of this duty requires too very different degrees of expenfe in the different periods of fociety. After the public inftitutions and public works neceffary for the defence of the fociety, and for the administration of justice, both of which have already been mentioned, the other works and inftitutions of this kind are chiefly thofe for facilitating the commerce of the fociety, and thofe for promoting the inftruction of the people. The inftitutions for inftruction are of two kinds; those for the education of the youth, and those for the inftruction of people of all ages. confideration of the manner in which the expense of those different forts of public works and institutions may be moft properly defrayed, will divide this third part of the present chapter into three different articles. ARTICLE I. The Of the public Works and Inftitutions for facilitating the Commerce of the Society. And, firft, of those which are neceffary for facili tating Commerce in general. THAT the erection and maintenance of the public works which facilitate the commerce of any country', fuch as good roads, bridges, navigable canals, harbours, &c. muft require very |