It has been objected to me, that I have exposed too freely the secrets of trade.  The only real secrets of trade are industry, integrity, and knowledge:  to the possessors of these no exposure can be injurious; and they never fail to produce respect and wealth.

The alterations in the present edition are so frequent, that I found it impossible to comprise them in a supplement.  But the three new chapters, ‘On money as a medium of exchange’; ’On a new system of manufacturing’; and ’On the effect of machinery in reducing the demand for labour’; will shortly be printed separately, for the use of the purchasers of the first edition.

I am inclined to attach some importance to the new system of manufacturing; and venture to throw it out with the hope of its receiving a full discussion among those who are most interested in the subject.  I believe that some such system of conducting manufactories would greatly increase the productive powers of any country adopting it; and that our own possesses much greater facilities for its application than other countries, in the greater intelligence and superior education of the working classes.  The system would naturally commence in some large town, by the union of some of the most prudent and active workmen; and their example, if successful, would be followed by others.  The small capitalist would next join them, and such factories would go on increasing until competition compelled the large capitalist to adopt the same system; and, ultimately, the whole faculties of every man engaged in manufacture would be concentrated upon one object—­the art of producing a good article at the lowest possible cost—­whilst the moral effect on that class of the population would be useful in the highest degree, since it would render character of far greater value to the workman than it is at present.

To one criticism which has been made, this volume is perfectly open.  I have dismissed the important subject of the patent-laws in a few lines.  The subject presents, in my opinion, great difficulties, and I have been unwilling to write upon it, because I do not see my way.  I will only here advert to one difficulty.  What constitutes an invention?  Few simple mechanical contrivances are new; and most combinations may be viewed as species, and classed under genera of more or less generality; and may, in consequence, be pronounced old or new, according to the mechanical knowledge of the person who gives his opinion.

Some of my critics have amused their readers with the wildness of the schemes I have occasionally thrown out; and I myself have sometimes smiled along with them.  Perhaps it were wiser for present reputation to offer nothing but profoundly meditated plans, but I do not think knowledge will be most advanced by that course; such sparks may kindle the energies of other minds more favourably circumstanced for pursuing the enquiries.  Thus I have now ventured to give some speculations on the mode of blowing furnaces for smelting iron; and even supposing them to be visionary, it is of some importance thus to call the attention of a large population, engaged in one of our most extensive manufactures, to the singular fact, that four-fifths of the steam power used to blow their furnaces actually cools them.