Centralization tends towards taxing the people for building up great institutions at a distance from those who pay the taxes; decentralization towards leaving to the people to tax themselves for the support of common and high schools in their immediate neighborhood.  The first tends towards placing the man who has instruction to sell at a distance from those who need to buy it; while the other tends towards bringing the teacher to the immediate vicinity of the scholars, and thus diminishing the cost of education.  The effects of the latter are seen in the fact that the new States, no less than the old ones, are engaged in an effort to enable all, without distinction of sex or fortune, to obtain the instruction needful for enabling them to become consumers of books, and customers to the men who produce them.  Massachusetts exhibits to the world 182,000 scholars in her public schools; New York, 778,000 in the public ones, and 75,000 in the private ones; and Iowa and Wisconsin are laying the foundation of a system that will enable them, at a future day, to do as much.  Boston taxes herself $365,000 for purposes of education, while Philadelphia expends more than half a million for the same purposes, and exhibits 50,000 children in her public schools.  Here we have, at once, a great demand for instructors, offering a premium on intellectual effort, and its effect is seen in the numerous associations of teachers, each anxious to confer with the others in regard to improvement in the modes of education.  School libraries are needed for the children, and already those of New York exhibit about a million and a half of volumes.  Books of a higher class are required for the teachers, and here is created another demand leading to the preparation of new and improved books by the teachers themselves.  The scholars enter life and next we find numerous apprentices’ libraries and mercantile libraries, producing farther demand for books, and aiding in providing reward for those to whom the world is indebted for them.  Everybody must learn to read and write, and everybody must therefore have books; and to this universality of demand it is due that the sale of those required for early education is so immense.  Of the works of Peter Parley it counts by millions; but if we take his three historical books (price 75 cents each) alone, we find that it amounts to between half a million and a million of volumes.  Of Goodrich’s United States it has been a quarter of a million.  Of Morse’s Geography and Atlas (50 cents) the sale is said to be no less than 70,000 per annum.  Of Abbott’s histories the sale is said to have already been more than 400,000, while of Emerson’s Arithmetic and Reader it counts almost by millions.  Of Mitchell’s several geographies it is 400,000 a year.