Another annoyance drew Warren’s attention to Norfolk. June 20, fifteen gunboats issued from the harbor before daylight, and under cover of darkness approached within easy range of a becalmed British frigate, the “Junon” of forty-six guns. For half an hour, from four o’clock till half-past four, the gunboats maintained, according to the official report of Commodore Cassin who commanded them, “a heavy, galling fire at about three quarters of a mile distance.”[388] Their armament was not mentioned, but probably they, like the gunboats on the Lakes, carried in part long thirty-two and twenty-four-pound guns. The attack was intended to test the offensive value of gunboats, and the result was not satisfactory. The fire of fifteen heavy guns for half an hour on a defenceless frigate within easy range should have caused great injury, but did not. When a breeze rose and enabled the “Junon” and a neighboring frigate, the “Barrosa,” to get under weigh, the gunboats were obliged to retire with the loss of one man killed and two wounded. The “Junon” also had one man killed, but received only one or two shots in her hull.[389] The “Constellation” lay, under the guns of two forts and with every possible precaution, five miles up the Elizabeth River, at the Portsmouth navy-yard. The utmost pains had been taken to provide against approach by water. Whatever incompetence or neglect was shown elsewhere, Norfolk was under the command of able officers in both services, who neglected no means of defence. General Wade Hampton had fortified the interior line immediately below the town, where two strong forts were constructed under the direction of Captain Walker Keith Armistead of the Engineers, the first graduate of the West Point Academy in 1803. Five miles below these forts, where the river widened into Hampton Roads, Brigadier-General Robert Taylor of the Virginia militia, and Captain John Cassin commanding at the navy-yard, established a second line of defence, resting on Craney Island on the left, supported by fifteen or twenty gunboats moored across the channel. A battery of seven guns was established on the island covering the approach to the gunboats, so that the capture of the island was necessary to the approach by water. The force on the island consisted of about seven hundred men, of whom less than a hundred were State troops. The rest were infantry of the line, riflemen, seamen, and marines.[390] The town and forts were strongly garrisoned, and a large body of State militia was constantly on service.