_The Bureau of the Census_ is charged with the duty of taking the decennial census of the United States, including the collection of such special statistics as Congress may authorize. The first census, that of 1790, was taken under the direction of the United States marshals in their respective districts; the statistics collected related only to population, and the schedule embraced only six questions. In 1880 the use of the marshals was done away with and a corps of census supervisors provided. Until 1902 the machinery for taking the census was organized anew for each census, but in the latter year provision was made for a permanent census bureau. The schedule of inquiries has increased from decade to decade until it now embraces a wide range of questions relating not only to population, but also to vital statistics, agriculture, manufactures, defective and criminal classes, cotton production, statistics of cities, state and local finances, transportation, mining, and various other matters, the results of which are published in a series of large volumes and in special bulletins. At the head of the bureau is a director, who is aided by an assistant director, a number of statisticians and experts, and a corps of local supervisors and enumerators. The census work was in the charge of the department of state until 1850, when it was transferred to the department of the interior. _The Bureau of Navigation_[94] is charged with the general superintendence of the merchant marine of the United States and of the enforcement of the navigation laws. It has charge of the registration of American vessels engaged in the foreign trade, and of the enrollment and licensing of vessels in the coasting trade. It supervises the execution of the tonnage laws and the collection of tonnage duties; prepares an annual list of vessels registered under the American flag; and supervises the work of the United States shipping commissioners, who administer the laws for the protection of seamen. [94] This bureau in the department of commerce must not be confused with the bureau of navigation in the navy department, already described. _The Steamboat Inspection Service_ is charged with the administration of the laws providing for the inspection of steam and sailing vessels registered under the American flag; with the examination and licensing of officers of such vessels, and with the protection of life and property on water. At the head of the service is an inspector general, who is aided by ten supervising inspectors, each of the latter having under his supervision a number of local inspectors stationed at the important commercial ports. All vessels must be inspected once a year as to their safety, construction, and facilities for protection against fire.