The commissioner of the general land office superintends the surveys and sales of the lands belonging to the national government.  The United States surveys divide the public lands into ranges, townships, sections, and fractions of sections.  Ranges are bounded by north and south lines, six miles apart, and are numbered east and west.  Ranges are divided into townships, each six miles square, numbered north and south.  A township is divided into thirty-six sections, each one mile square, and containing six hundred and forty acres of land; and sections are divided into quarter sections.

The commissioner of Indian affairs has charge of questions relating to the government of the Indians.  Its agents make treaties, manage lands, issue rations and clothing, and conduct trade with the Indians.

The commissioner of patents conducts all matters pertaining to the granting of patents for useful inventions, discoveries, and improvements.

A patent gives the inventor the exclusive right to manufacture, sell, and use the patented article for a period of seventeen years.

A copyright, which is somewhat similar to a patent, gives the author of a book the exclusive right to print, publish, and sell it for a period of twenty-eight years, with the privilege at the expiration of that time of renewing for twenty-eight years more.

An inventor or author may sell a patent or copyright, as well as other property.

The commissioner of education investigates the condition and progress of education in the several States and Territories, and collects information relating to schools, school systems, and methods of teaching.  The facts collected are distributed among the people in annual reports published by the office.

The director of the geological survey sends out parties of scientific men, who explore various parts of the Union, trace the sources of rivers, measure the heights of lands, and gather other facts relating to the natural resources of the country.  He publishes excellent maps of the regions that have been explored.

DEPARTMENT OF JUSTICE.—­The attorney-general presides over the department of justice.  He is the chief law officer of the government, and the legal adviser of all the departments.  He is assisted by the solicitor-general, who is the second officer in rank; by nine assistant attorney-generals, and by several solicitors for particular departments.  The department of justice conducts before the supreme court all suits to which the United States is a party; conducts suits arising in any of the departments, when requested by the head thereof; exercises supervision over the district attorneys and marshals of the United States district courts; examines the titles of lands proposed to be purchased by the United States, as sites for forts, arsenals, barracks, dockyards, customhouses, post-offices, and other public purposes; examines and reports upon applications for judicial offices and other positions requiring legal ability.