The Board of Engineers and the Topographical Corps have been in constant and active service in surveying the coast and projecting the works necessary for its defense. The Military Academy has attained a degree of perfection in its discipline and instruction equal, as is believed, to any institution of its kind in any country. The money appropriated for the use of the Ordnance Department has been regularly and economically applied. The fabrication of arms at the national armories and by contract with the Department has been gradually improving in quality and cheapness. It is believed that their quality is now such as to admit of but little improvement. The completion of the fortifications renders it necessary that there should be a suitable appropriation for the purpose of fabricating the cannon and carriages necessary for those works. Under the appropriation of $5,000 for exploring the Western waters for the location of a site for a Western armory, a commission was constituted, consisting of Colonel McRee, Colonel Lee, and Captain Talcott, who have been engaged in exploring the country. They have not yet reported the result of their labors, but it is believed that they will be prepared to do it at an early part of the session of Congress. During the month of June last General Ashley and his party, who were trading under a license from the Government, were attacked by the Ricarees while peaceably trading with the Indians at their request. Several of the party were killed and wounded and their property taken or destroyed. Colonel Leavenworth, who commanded Fort Atkinson, at the Council Bluffs, the most western post, apprehending that the hostile spirit of the Ricarees would extend to other tribes in that quarter, and that thereby the lives of the traders on the Missouri and the peace of the frontier would be endangered, took immediate measures to check the evil. With a detachment of the regiment stationed at the Bluffs he successfully attacked the Ricaree village, and it is hoped that such an impression has been made on them as well as on the other tribes on the Missouri as will prevent a recurrence of future hostility. The report of the Secretary of War, which is herewith transmitted, will exhibit in greater detail the condition of the Department in its various branches, and the progress which has been made in its administration during the three first quarters of the year. I transmit a return of the militia of the several States according to the last reports which have been made by the proper officers in each to the Department of War. By reference to this return it will be seen that it is not complete, although great exertions have been made to make it so. As the defense and even the liberties of the country must depend in times of imminent danger on the militia, it is of the highest importance that it be well organized, armed, and disciplined throughout the Union.