could get no lumber for supports to his gallery, but he tore down an old bridge in rear of the lines and utilized that; barrows were wanting, in which to remove the earth taken from the mine, but he bound old cracker-boxes with hoops of iron wrenched from the pork-barrels and used them instead; above all, he needed an accurate instrument to make the necessary triangulations, and although there was a new one at army headquarters, he was forced to send to Washington for an old-fashioned theodolite, and make that answer his purpose.
Despite all this and more, he persevered, working on until
THE BUSY HAMMERING OF THE CONFEDERATES OVERHEAD,
engaged in laying platforms for their guns, assured him that he was well under the doomed salient.
By July 23d the mine was finished. It consisted of a main gallery five hundred and ten and eight-tenths feet in length, with lateral galleries right and left, measuring respectively thirty-eight and thirty-seven feet, and forming the segment of a circle concave to the Confederate lines.[1] From mysterious paragraphs in the Northern papers and from reports of deserters, though these last were vague and contradictory, Lee and Beauregard suspected that the enemy was mining in front of some one of the three salients on Beauregard's front, and the latter officer had, in consequence, directed counter-mines to be sunk from all three, meanwhile constructing gorge-lines in rear, upon which the troops might retire in case of surprise or disaster. Batteries of eight and ten-inch, and Coehorn mortars were also established to assure a cross and front fire on the threatened points. But the counter-mining on part of the Confederates was after a time discontinued, owing to the lack of proper tools, the inexperience of the troops in such work, and the arduous nature of their service in the trenches.[2]
The mine finished, official brows began to relax, and Pleasants asking for 12,000 pounds of powder, got 8,000 and was thankful, together with 8,000 sand bags to be used in tamping. On the 27th of July, the charge, consisting of 320 kegs of powder, each containing, 25 pounds, was placed in the mine, and before sunset of 28th the tamping was finished and the mine ready to be sprung.[3]
