The President and Cabinet are gaining confidence; and the measures of the Administration will no longer be limited to the defence of the capital. Secretary Welles has already sent orders to Captain Hudson to purchase six steamers, with instructions to consult you in regard to the matter. I regret that the Secretary was not ready to put the matter into the hands of commissioners, who would have acted efficiently and promptly. Mr. Welles will accept, as a part of the quota, such vessels as may have been purchased by Mr. Forbes. Senator Grimes of Iowa will probably give Mr. Crowninshield an order for arms. The United States Government may do the same; but no definite action has yet been taken. Martial law will be proclaimed here to-morrow. Colonel Mansfield will be appointed general, and assigned to this district. He is one of the most efficient officers in the country. Baltimore is to be closed in from Havre-de-Grace, from the Relay House, from the Carlisle line, and by an efficient naval force. She will be reduced to unconditional submission. The passage of the troops through Maryland has had a great moral effect. The people are changing rapidly in the country places. Many instances of a popular revolution, in towns through which troops have passed or been stationed, have come to my knowledge. I came to Washington with the Twelfth New York Regiment; and from Annapolis Junction there were cheers from three fourths of the houses by the wayside. Everything appears well at Annapolis, where General Butler commands in person. There is a large body of troops, the people are gradually gaining confidence in the army and the Government, and the regulations seem to be effective. General Butler is popular with the officers whom I met. He has taken command of the highlands that command the town and the encampment. All sorts of rumors are spread among the troops concerning an attack upon the Annapolis Station; but the place can be defended under any conceivable circumstances. I am sorry to say, that everything is in confusion at Annapolis Junction, and a moderate force might, in a single night, break off the connection of this city with the North. Each colonel, as he moves towards Washington, commands for twelve or twenty-four hours. My own belief, however, is, that Maryland will never see two thousand men together as a military organization in opposition to the Government. I presume that your Excellency has means of obtaining information concerning the condition of Massachusetts men, morally and physically; but, as I am here, I shall try to obtain and transmit any information that seems important. I may say now, that the Eighth Regiment is quartered in the rotunda of the Capitol; and a military man, not of Massachusetts, says, that they are already suffering from the cold and dampness of the place. He advises tents and out-door encampment.