BURG, PA., June 16th.--Midnight.--Rebel cavalry to-day occupied
Littletown, eleven miles from Gettysburg, but at last accounts had not
advanced beyond that point.

"The rebel officers at Chambersburg stated that they were only waiting
for infantry to move forward. The authorities are inclined to believe,
however, that they will not move farther North.

"The farmers in the valley are sending their horses and cattle into the
mountains.

"The rebels are gathering up all the negroes that can be found.

"Private property has been respected.

"They burned the railroad bridge across Scotland Creek, six miles this
side of Chambersburg.

HARPER'S FERRY INVESTED.

"BALTIMORE, June 16th.--Fugitives from Hagerstown report the rebels
picketing all the roads and not permitting any one to pass.

"The force that passed through were all cavalry, under Jenkins and
Imboden, and did not exceed 2500.

"All was quiet at Frederick up to five o'clock this evening, though the
people were greatly excited and hundreds were leaving.

"HARRISBURG, June 17th.--The aspect of affairs, so far as can be judged
by the reports from the border, seems to be this:

"The rebel force occupy Hagerstown and such other points as leave them
free to operate either against Harrisburg or Baltimore.

"Apprehensions are entertained by the people of Altoona and other points
on the line of the Pennsylvania Railroad, that the rebels will strike
for the West, and then go back to their own soil by way of Pittsburg and
Wheeling.

"The fortifications constructed on the hills opposite Harrisburg are
considered sufficient protection for the city, and an offensive movement
on our part is not unlikely."

JUNE 21ST.--To-day we have an account of the burning of Darien, Ga. The
temptation is strong for our army to retaliate on the soil of
Pennsylvania.

JUNE 22D.--To-day I saw the memorandum of Mr. Ould, of the conversation
held with Mr. Vallandigham, for file in the archives. He says if we _can
only hold out_ this year that the peace party of the North would sweep
the Lincoln dynasty out of political existence. He seems to have thought
that our cause was sinking, and feared we would submit, which would, of
course, be ruinous to his party! But he advises strongly against any
invasion of Pennsylvania, for that would unite all parties at the North,
and so strengthen Lincoln's hands that he would be able to crush all
opposition, and trample upon the constitutional ri