...tion, therefore, is a threatening one.--Crossing over to Bath and Sir John's Run, and de stroying the Great Cacapon Bridge, as they did before, and at the same time repeating their demonstration upon Martinsburg , and reducing the Opequan and Pillar bridges to ashes, they can command the road again, and get New Creek in their clutches at last, where, fortunately, however, we have but little left that would be...