A. In their power of shortening labour, or otherwise accomplishing (as ships) what human strength unaided could not. The kinds of work which are severally best accomplished by hand or by machine;--the effect of machinery in gathering and multiplying population, and its influence on the minds and bodies of such population; together with the conceivable uses of machinery on a colossal scale in accomplishing mighty and useful works, hitherto unthought of, such as the deepening of large river channels;--changing the surface of mountainous districts;--irrigating tracts of desert in the torrid zone;--breaking up, and thus rendering capable of quicker fusion edges of ice in the northern and southern Arctic seas, etc., so rendering parts of the earth habitable which hitherto have not been so, are to be studied under this head. B. The value of instruments is, secondarily, in their aid to abstract sciences. The degree in which the multiplication of such instruments should be encouraged, so as to make them, if large, easy of access to numbers (as costly telescopes), or so cheap as that they might, in a serviceable form, become a common part of the furniture of households, is to be considered under this head. 3. Food, medicine, and articles of luxury. Under this head we shall have to examine the possible methods of obtaining pure and nourishing food in such security and equality of supply as to avoid both waste and famine; then the economy of medicine and just range of sanitary law; finally, the economy of luxury, partly an aesthetic and partly an ethical question. 4. Books. The value of these consists-- A. In their power of preserving and communicating the knowledge of facts. B. In their power of exciting vital or noble emotion and intellectual action. They have also their corresponding negative powers of disguising and effacing the memory of facts, and killing the noble emotions, or exciting base ones. Under these two heads we have to consider the economical and educational value, positive and negative, of literature;--the means of producing and educating good authors, and the means and advisability of rendering good books generally accessible, and directing the reader's choice to them. 5. Works of art. The value of these is of the same nature as that of books, but the laws of their production and possible modes of distribution are very different, and require separate examination. SECTION II.--MONEY. Under this head, we shall have to examine the laws of currency and exchange; of which I will note here the first principles. Money has been inaccurately spoken of as merely a means of circulation. It is, on the contrary, an expression of right. It is not wealth, being the sign[69] of the relative quantities of it, to which, at a given time, persons or societies are entitled. [69] Always, and necessarily, an imperfect sign; but capable of approximate accuracy if rightly ordered.