“The wire for the return current from the battery is passed from shell to shell and along the connecting rope, which lies at the bottom. The wire that passes from cask to cask is stopped slack to the buoy rope from the shell up to the cask, to which it is securely seized to prevent any strain upon that part which enters the cask. The return wire is stopped in like manner down along the span to the next shell, as per the rough sketch. At 4 (in the sketch) the two cords are frapped together, loaded with trace chains a fathom apart, and carried ashore to the galvanic battery. “For batteries we have 21 Wollastons, each trough containing eighteen pairs of plates, zinc and iron, ten by twelve inches. The first range is called 1, the second 2, and the third 3, and the wires are so labeled. Thus all of each range are exploded at once. “Besides these, there are two ranges of two tanks each, planted opposite the battery at Chapin’s Bluff. When they were planted, it was not known that a battery was to be erected below. These four tanks contain about 6,000 pounds of powder. The great freshet of last month carried away the wires that were to operate the first pair, ‘A’ (in a diagram enclosed, which showed the exact location of the various mines). “Lieutenant Davidson, who with the _Teaser_ and her crew has assisted me with a most hearty good will, has dragged for the tanks without success. They rest on the bottom. Could they be found, it was my intention to raise the four, examine them, and, if found in good order, place them below the range, ‘I’. “Lieutenant William L. Maury, assisted by Acting Master W. F. Carter and R. Rollins, was charged with the duty of proving the tanks and packing them in casks. There are eleven others, each containing 70 pounds of powder. When tested in the barrels and found ready for use, they will be held in reserve in case of accident to those already down. A larger number was not prepared, for the want of powder. There are a quantity of admirable insulated wire, a number of shells for anchors or torpedoes, and a sufficient quantity of chains for the wires remaining. They will be put in the navy store for safe-keeping. The galvanic batteries; viz., 21 Wollastons and 1 Cruikshank, the latter loaned by Dr. Maupin of the University of Virginia, with spare acids, sulphuric and nitric, are at Chapin’s Bluff in charge of Acting Master Cheeney. He has also in jugs a sufficient quantity mixed to work the batteries, and ready to be poured in for use. “It is proper that I should mention to the Department in terms of commendation the ready and valuable assistance afforded by Dr. Morris, president telegraph company, and his assistant, especially by Mr. Goldwell. My duties in connection with these batteries being thus closed, I have the honor to await your further orders”.