From the Richmond Whig, 5/1/1862, p. 3, c. 3

DEFENCES OF JAMES RIVER. - The Enquirer of yesterday states that the navigation of James river will be kept open without interruption, but at certain points barricades are being made on either side of the channel, of double rows of piles filled in with stones, leaving a channel way of eighty feet. At each of these points of ingress a number of vessels are to be placed, laden with stone, which may be sunk at a moment's notice directly in the channel. If the necessity does not occur, of course the river will remain unobstructed, and, we may say, improved as the effect of the side barricades will be to aid the current and keep the channel clean.

We would suggest, in addition to these precautions that hogsheads or barrels, filled with blocks of granite, be placed on some of the sloping bluffs along the river, ready to be rolled in either to obstruct the channel, or to crush a passing vessel of the enemy.