...ng first set fire to the warehouse of Oaks & Linn.--The fire was afterwards subdued by the citizens. They retreated, it is supposed, towards Hagerstown. The telegraphic operator is now at Chambersburg and communication has been re-established. Washington, June 17.--The official telegram from Gen. Tyler, at Harper's Ferry, says the enemy has an infantry and artillery force of from 7,000 to 8,...