Gen. Lyon issued another proclamation to the people of Missouri from his camp at Booneville. He released the prisoners taken in the late engagement, in consideration of their youth and of the deceit that had been practised upon them, simply requiring their pledge not again to bear arms against the United States. His proclamation warned all persons against presuming upon a like clemency in future, as the continuance of treason would certainly render harsh measures necessary.--(Doc. 260.)
The Federal force at Hagerstown and Williamsport, Md., comprise the Pennsylvania 1st, 2d, 8d, 7th, 11th, 13th, and 24th Regiments, together with the First Rhode Island Regiment, two Regiments of United States Regulars, and  seven hundred United States Cavalry. Included in this formidable body are Capt. Doubleday's corps and McMullen's Company of Philadelphia Rovers. The portion of the force which forded the river at Williamsport were under command of Gen. Thomas, and comprised the two regiments of regulars and about six hundred of the Rhode Islanders. The men waded through the stream generally up to their hips in water, and occasionally up to their arms. Their passage on the occasion is said to have been a very imposing and spirited spectacle. The men dashed into the stream singing “Dixie” and other popular camp airs with great vim and enthusiasm.--National Intelligencer, June 20.
Near Conrad's Ferry, Maryland, the rebels practised upon the Federal troops from the opposite side of the Potomac with three or four 6-pounders. Their fire was returned from the rifle pieces of some twenty picked marksmen, who in the course of their firing brought down one of the enemy's gunners. The distance across is so great, however, that even rifled muskets are of little avail except by chance shots.--N. Y. Evening Post, June 18.
The Twenty-Seventh Pennsylvania Regiment, (mostly Germans,) Colonel Einstein, about one thousand strong, passed through Baltimore, Md., on the route to the seat of war. They are well armed and equipped, and have entered the service with the spirit of true soldiers. Whilst at Camden, opposite Philadelphia, where they encamped for some time, they were treated with great kindness by the people of that city.--(Doc. 261.)
A balloon ascension for military purposes took place at Washington. The elevation attained was not very great, though it was perfectly satisfactory as an experiment. The aeronauts were Prof. Lowe, Gen. Burns, of the Telegraph Company, and H. C. Robinson, operator. The balloon was connected with the War Department by telegraph. The first message ever telegraphed from a balloon was then sent to the President of the United States by Prof. Lowe. It was as follows:
An official order from the Duke of New-castle, forbidding privateers to enter the ports of Canada, was published in the Montreal (Canada) papers.--(Doc. 262.)
The Fourteenth Regiment N. Y. S. V. passed through New York City en route for the Seat of War.--The Eighteenth Regiment N. Y. Volunteers left Albany.--(Doc. 263.)
Capt. Budd, commanding the United States steamer Resolute, arrived at Washington, bringing as a prize the schooner Buena Vista, seized in the St. Mary's River. He captured two other vessels — namely, the schooner Bachelor and the sloop H. Day. The former had disregarded a warning given several days ago, and had deceived Captain Rowan by false statements, and was found on the Maryland side, opposite Matthias Point, at a place where it was convenient for crossing. They belonged to the same owner.--N. Y. Commercial Advertiser, June 19.