To increase the inconvenience of Howe's situation by intercepting his supplies Washington ordered 600 militia, commanded by General Potter, to cross the Schuylkill and scour the country between that river and Chester, and the militia on the Delaware, above Philadelphia, were directed to watch the roads in that vicinity. The more effectually to stop those who were seduced by the hope of gold and silver to supply the enemy at this critical time, Congress passed a resolution subjecting to martial law and to death all who should furnish them with provisions, or certain other enumerated articles, who should be taken within thirty miles of any city, town, or place in Jersey, Pennsylvania, or Delaware, occupied by British troops. These arrangements being made to cut off supplies from the country, Washington took a strong position at White Marsh, within fourteen miles of Philadelphia. Meanwhile General Howe was actively preparing to attack Fort Mifflin from the Pennsylvania shore. He erected some batteries at the mouth of the Schuylkill, in order to command Webb's Ferry, which were attacked by Commodore Hazlewood and silenced; but the following night a detachment crossed over Webb's Ferry into Province Island, and constructed a slight work opposite Fort Mifflin, within two musket shots of the blockhouse, from which they were enabled to throw shot and shells into the barracks. When daylight discovered this work three galleys and a floating battery were ordered to attack it and the garrison surrendered. While the boats were bringing off the prisoners, a large column of British troops were seen marching into the fortress, upon which the attack on it was renewed, but without success, and two attempts made by Lieutenant-Colonel Smith to storm it failed. [1] In a few nights works were completed on the high ground of Province Island, which enfiladed the principal battery of Fort Mifflin, and rendered it necessary to throw up some cover on the platform to protect the men who worked the guns. The aid expected from the Jersey militia was not received. "Assure yourself," said Lieutenant-Colonel Smith, in a letter pressing earnestly for a reinforcement of Continental troops, "that no dependence is to be put on the militia; whatever men your Excellency determines on sending, no time is to be lost." The garrison of Fort Mifflin was now reduced to 156 effectives, and that of Red Bank did not much exceed 200. In consequence of these representations Washington ordered Col. Christopher Greene, of Rhode Island, with his regiment, to Red Bank, and Lieut.-Col. John Greene, of Virginia, with about 200 men, to Fort Mifflin.