This money was not, however, immediately forthcoming, and Maury complained that he was forced to lay on his oars and wait for the word from Congress, “Go ahead!” He also wrote that he was anxious to mine the river passes to both Richmond and Fredericksburg with these submarine batteries which would be exploded by electricity, but that lack of materials was delaying the project. During this delay, he planned another attack on the Union ships off Newport News. This materialized in an attempt which was made, on October 10, by Lieutenant Robert D. Minor to sink the _Savannah_ and the _Minnesota_, but this second trial also met with failure. Maury had planned to take part himself in the attack, but was prevented from doing so by his being ordered to Richmond with the expectation of being sent to mine the Mississippi River. He did not, however, go on this mission, though he had considerable correspondence with General Polk, who wished to place mines in the river at Columbus, Kentucky. Some mines were sent to Memphis with full instructions as to how they should be planted; and here others were constructed, after Maury’s model, to be used elsewhere on the river. About the first of May, 1862, Maury had the good fortune to secure ten miles of insulated wire which enabled him to mine the James River with electric mines, according to the plans which he had been compelled to lay aside for several months for lack of material. This wire had been used by the Federals in attempting to lay a submarine telegraph across the Chesapeake from Fortress Monroe to Eastville; but having been forced to abandon the attempt, they left the wire in the water and the waves cast it upon the beach near Norfolk where a friend, Dr. Morris, secured it for Maury’s use. The following report describes the mines that were then constructed and relates how they were laid down in the James River early in June, 1862: “The James River is mined with fifteen tanks below the iron battery at Chapin’s (Chaffin’s) Bluff. They are to be exploded by means of electricity. Four of the tanks contain 160 pounds of powder; the eleven others hold 70 pounds each. All are made of boiler plate. They are arranged in rows as per diagram, those of each row being 30 feet apart. Each tank is contained in a water-tight wooden cask, capable of floating it but anchored and held below the surface from three to eight feet, according to the state of the tide. The anchors of each are an 18-inch shell and a piece of kentledge, so placed as to prevent the barrels from fouling the buoy ropes at the change of the tide. Each shell of a row is connected with the one next to it by a stout rope thirty feet long and capable of lifting it in case the cask be carried away. The casks are water-tight, as are also the tanks, the electric cord entering through the same head.