Feeble as was the American army, this movement was not effected without some loss. On the evacuation of Elizabeth town, General Maxwell attacked the British rear, and captured about seventy men with a part of their baggage. The American troops had been so diminished by the extreme severity of the service, that it was with much difficulty the appearance of an army could be maintained. Fresh militia and volunteers arrived in camp, whose numbers were exaggerated by report. These additions to his small remaining regular force enabled the General to take different positions near the lines of the enemy, to harass him perpetually, restrain his foraging parties, and produce considerable distress in his camp. {January 12.} While, with little more than an imaginary army, General Washington thus harassed and confined his adversary, he came to the hazardous resolution of freeing himself and his troops from the fear of a calamity which he found it impossible to elude, and which had proved more fatal in his camp than the sword of the enemy. [Sidenote: American army inoculated.] Inoculation having been rarely practised in the western world, the American youth remained liable to the small pox. Notwithstanding the efforts to guard against this disease, it had found its way into both the northern and middle army, and had impaired the strength of both to an alarming degree. To avoid the return of the same evil, the General determined to inoculate all the soldiers in the American service. With the utmost secrecy, preparations were made to give the infection in camp; and the hospital physicians in Philadelphia were ordered to carry all the southern troops, as they should arrive, through the disease. Similar orders were also given to the physicians at other places; and thus an army exempt from the fear of a calamity which had, at all times, endangered the most important operations, was prepared for the ensuing campaign. This example was followed through the country; and this alarming disease was no longer the terror of America. As the main body of the British army was cantoned in Jersey, and a strong detachment occupied Rhode Island, General Washington believed that New York could not be perfectly secure. His intelligence strengthened this opinion; and, as an army, respectable in point of numbers, had been assembled about Peekskill, he ordered General Heath to approach New York for the purpose of foraging, and, should appearances favour the attempt, of attacking the forts which guarded the entrance into the island. The hope was entertained that General Howe, alarmed for New York, might either withdraw his troops from Jersey, or so weaken his posts in that state as to endanger them. Should this hope be disappointed, it was believed that something handsome might be done, either on York or Long Island. [Sidenote: General Heath moves down to Kingsbridge, but returns to Peekskill without effecting anything.]