Few facts testify more significantly of the value to the army and the American cause of that long course of training, in the presence of the enemy, than the preparations thus made by Washington, without the knowledge of most of the officers of his command. He collected forty-five batteaux, each capable of transporting eighty men, and built two floating batteries of great strength and light draught of water. Fascines, gabions, carts, bales of hay, intrenching-tools, and two thousand bandages, with all other contingent supplies, were gathered, and placed under a guard of picked men. Three nights of _mock bombardment_ kept the garrison on the alert, awaiting an assault. "On the night of the fourth of March, and through all its hours, from candle-lighting time to the clear light of another day, the same incessant thunder rolled along over camps and city; the same quick flashes showed that fire was all along the line, and still, both camps and city dragged through the night, waiting for the daylight to test the work of the night, as daylight had done before." When daylight came,-- "Two strong redoubts capped Dorchester Heights." By the tenth of March, the Americans had fortified Nook's Hill, and this drove the British from Boston Neck. Eight hundred shot and shell were thrown into the city during that night. On the morning of March 17, the British embarked for Halifax. Five thousand American troops entered the city, under General Ward (the venerable predecessor of Washington) as the last boats left. On the eighteenth of March, and before the main army had entered Boston, General Heath was ordered to New York with five regiments of infantry and a part of the field artillery. On the twenty-seventh, the whole army, excepting a garrison of five regiments, was ordered forward, General Sullivan leading the column. On the evening of April fourteenth, after the last brigade marched, Washington started for his new field of duty. The siege of Boston is indeed memorable for that patient, persistent pressure by which the Colonists grasped, and held fast, all approaches to the city, until a sufficient force could be organized for a systematic siege; but, as the eye rests upon an outline map of the principal works of the besieging force, and we try to associate Ploughed Hill, Winter Hill, Prospect Hill, and other memorable strongholds, with the surroundings of to-day, we are glad to find an abounding source of comfort in the assurance, that the whole struggle for our National Independence is indelibly associated with the names, the vigils, and the experiences which belong to those long months of education in the art and appliances of war.