In what has preceded, I have, of course, spoken of inventions and improvements when generally diffused. It is hardly necessary to say that as long as an invention or an improvement is used by so few that they derive a special advantage from it, it does not, to the extent of this special advantage, affect the general distribution of wealth. So, in regard to the limited monopolies created by patent laws, or by the causes which give the same character to railroad and telegraph lines, etc. Although generally mistaken for profits of capital, the special profits thus arising are really the returns of monopoly, as has been explained in a previous chapter, and, to the extent that they subtract from the benefits of an improvement, do not primarily affect general distribution. For instance, the benefits of a railroad or similar improvement in cheapening transportation are diffused or monopolized, as its charges are reduced to a rate which will yield ordinary interest on the capital invested, or kept up to a point which will yield an extraordinary return, or cover the stealing of the constructors or directors. And, as is well known, the rise in rent or land values corresponds with the reduction in the charges. As has before been said, in the improvements which advance rent, are not only to be included the improvements which directly increase productive power, but also such improvements in government, manners, and morals as indirectly increase it. Considered as material forces, the effect of all these is to increase productive power, and, like improvements in the productive arts, their benefit is ultimately monopolized by the possessors of the land. A notable instance of this is to be found in the abolition of protection by England. Free trade has enormously increased the wealth of Great Britain, without lessening pauperism. It has simply increased rent. And if the corrupt governments of our great American cities were to be made models of purity and economy, the effect would simply be to increase the value of land, not to raise either wages or interest. CHAPTER IV. EFFECT OF THE EXPECTATION RAISED BY MATERIAL PROGRESS. We have now seen that while advancing population tends to advance rent, so all the causes that in a progressive state of society operate to increase the productive power of labor tend, also, to advance rent, and not to advance wages or interest. The increased production of wealth goes ultimately to the owners of land in increased rent; and, although, as improvement goes on, advantages may accrue to individuals not land holders, which concentrate in their hands considerable portions of the increased produce, yet there is in all this improvement nothing which tends to increase the general return either to labor or to capital. But there is a cause, not yet adverted to, which must be taken into consideration fully to explain the influence of material progress upon the distribution of wealth.