President from the line of the Army, as he may deem necessary for the service, and shall be instructed in and perform all the duties of sappers, miners, and pontoniers, and shall, moreover, under the orders of the chief engineer, be liable to serve by detachments in overseeing and aiding laborers upon fortifications or other works under the Engineer Department, and in supervising finished fortifications, as fort-keepers, preventing injury and making repairs.

SEC. 4. It shall be the duty of the colonel of the Engineer Corps, subject to the approval of the Secretary of War, to prescribe the number, quantity, form, dimensions, &c., of the necessary vehicles, arms, pontoons, tools, implements, and other supplies for the service of the said company as a body of sappers, miners, and pontoniers.

SEC. 5. The corps of artillery, which shall also be charged with ordnance duties, shall consist of one colonel, one lieutenant-colonel, ten majors, and forty companies of artillerists and artificers; and each company shall consist of one captain, two first lieutenants, one second lieutenant, four sergeants, four corporals, two musicians, and seventy privates. There shall also be one adjutant, to be selected by the colonel from the first lieutenants, and one sergeant-major, to be selected from the enlisted men of the regiment.

SEC. 7. The regiment of cavalry shall consist of one colonel, one lieutenant-colonel, one major, and ten companies, each of which shall consist of one captain, one first lieutenant, two second lieutenants, four sergeants, four corporals, one farrier, one blacksmith, two musicians, and sixty privates. There shall also be one adjutant and one sergeant-major, to be selected as aforesaid.

SEC. 8. There shall be four brigadier-generals, who shall be assigned to such commands and duties as the President may specially direct, and shall be entitled to one aide-de-camp each, to be selected from the subalterns of the line of the Army, who, in addition to their duties as aides-de-camp, may perform the duties of assistant adjutants-general.

SEC. 9. All officers of the Army shall be appointed by the President, by and with the advice and consent of the Congress, and the rank and file shall be enlisted for a term not less than three nor more than five years, under such regulations as may be established.

SEC. 10. No officer shall be appointed in the Army until he shall have passed an examination satisfactory to the President, and in such manner as he may prescribe, as to his character and fitness for the service. The President, however, shall have power to postpone this examination for one year after appointment, if in his judgment necessary for the public interest.

SEC. 11. All vacancies in established regiments and corps, to and including the rank of colonel, shall be filled by promotion according to seniority, except in case of disability or other incompetency. Promotions to and including the rank of colonel shall be made regimentally in the infantry and cavalry, in the staff departments, and in the