In economic and social discussion the word reform is commonly opposed to the word revolution. It implies modification rather than abolition, gradual rather than violent change. Hence reforms of the system of land tenure do not include such radical proposals as those of land nationalisation or the Single Tax. On the other hand, some extension of State ownership of land, and some increase in the proportion of taxes imposed upon land, may quite properly be placed under the head of reform, inasmuch as they are changes in rather than a destruction of the existing system. In general, the reform measures needed are such as will meet the defects described in the last chapter; namely, monopoly, excessive gains, and exclusion from the land. Obviously they can be provided only by legislation; and they may all be included under two heads, ownership and taxation. By far the greater part of the more valuable lands of the country are no longer under the ownership of the State. Urban land is practically all in the hands of private proprietors. While many millions of acres of land suitable for agriculture are still under public ownership, almost all of this area requires a considerable outlay for irrigation, clearing, and draining before it can become productive. Forty years ago, three-fourths of the timber now standing was public property; at present about four-fifths of it is owned by private persons or corporations.[84] The bulk of our mineral deposits, coal, copper, gold, silver, etc., have likewise fallen under private ownership, with the exception of those of Alaska. The undeveloped water power remaining under government ownership has been roughly estimated at fourteen million horse power in the national forests, and considerably less than that amount in other parts of the public domain.[85] This is a gratifying proportion of the whole supply, developed and undeveloped, of this national resource, which is said to be somewhere between 27 and 60 millions horse power.[86] Only about seven million horse power has yet been developed, almost all of which is privately owned. _The Leasing System_