In the Indian service there is also a Board of “Indian Commissioners,” nine in number, authorized by act of Congress, approved April 10, 1869, men eminent for their intelligence and philanthropy, who serve without compensation, the object of the Commission being to co-operate with the President in efforts to maintain peace among the Indians, bring them upon reservations, relieve their necessities, and to encourage them in attempts at self-support. The Census Bureau is now a permanent branch of the Department of the Interior. It is in charge of a superintendent, and is assigned the duty of compiling the statistics which constitute the Census of the Republic. This enumeration is made every ten years. Some idea of the magnitude of the task may be gained from the fact that the tabulation and publication of the census of 1870 were not completed in January, 1873. The Bureau of Patents is a part of the Department of the Interior, but is in all its proportions and features so vast and imposing, that it is almost a separate department, as, indeed, it must become erelong. It is in charge of a Commissioner of Patents, who is appointed by the President of the United States, by and with the advice and consent of the Senate. It is intrusted with the duty of granting letters patent, securing to the inventor the control of and the reward from articles beneficial to civilization. It was formerly a part of the Treasury Department, and is one of the best known branches of the Government. Patents are not, as some persons suppose, monopolies, but are protections granted to individuals as rewards for, and incentives to discoveries and inventions of all kinds pertaining to the useful arts. This Bureau is allowed to charge for these letters of protection only the cost of investigating and registering the invention. It is a self-supporting institution, its receipts being largely in excess of its expenditures. If you have traced the many Bureaus of the Interior Department thus far, you have come to the conclusion that it needs a public building all to itself, and that it should be an immense one. A large brick building opposite the Patent-Office, on G street, is already exclusively occupied by the Bureau of Education.