There are two rivers by which Washington may be approached--the Potomac, on which it is situated, and the Patuxent, which flows in its rear. The British commander chose the latter, both on account of the facility of access, and for the purpose of destroying the powerful fleet of gunboats which had taken refuge in its creeks. This object was successfully accomplished on the 20th of August-- thirteen of the gunboats being destroyed and one captured, together with fourteen merchant vessels. The army, under the command of General Ross, on the following day disembarked. It numbered, including some marines, three thousand five hundred men, with two hundred sailors to drag the guns--two small three- pounders. For the defence of Washington, General Winder had been assigned a force of sixteen thousand six hundred regulars, and a levy of ninety-three thousand militia had been ordered. Of the latter, not one appeared; of the former, only about one-half mustered. The Americans had, however, twenty-six guns against two small pieces possessed by the British. General Winder took post at Bladensburg, a few miles from Washington. His batteries commanded the only bridge across the East Potomac. Ross determined to storm the bridge in two columns. Not for a moment did the war-bronzed veterans of the Peninsular war hesitate. Amid a storm of shot and shell, they dashed across the bridge, carried a fortified house, and charged on the batteries before the second column could come to their aid. Ten guns were captured. The American army was utterly routed, and fled through and beyond the city it was to defend. The lack of cavalry and the intense heat of the day prevented the pursuit by the British. The brilliant action was saddened to the victors by the loss of sixty-one gallant men slain and one hundred and eighty-five wounded. Towards evening the victorious army occupied the city. The destruction of the public buildings had been decreed, in retaliation for the pillage of Toronto and the wanton burning of Niagara. An offer was made to the American authorities to accept a money payment by way of ransom, but it was refused. The next day, the torch was ruthlessly applied to the Capitol, with its valuable library, the President's house, treasury, war office, arsenal, dockyard, and the long bridge across the Potomac. The enemy had already destroyed a fine frigate, a twenty-gun sloop, twenty thousand stand of arms, and immense magazines of powder. Even if justifiable as a military retaliation, this act was unworthy of a great and generous nation. The town of Alexandria was saved from destruction only by the surrender of twenty-one vessels, sixteen hundred barrels of flour, and a thousand hogsheads of tobacco.