We are much gratified to find that the work upon the Canal has been resumed with great vigor since the disappearance of the Cholera. — Many hundred hands are busily engaged near Harpers-Ferry, and every thing indicates an early completion of that part of the noble work which lies between the Point of Rocks and Harpers-Ferry. The mountain cliffs bow their rugged heads before the oft-plied instruments of labour, and that potent agent in war and peace, gun-powder. Success to the glorious enterprize.