paulins, 18 by 28 feet each; 9,156 feet 3-inch pine plank; 300 pounds 7-9 inch, and 300 pounds 4-inch, spikes and nails; 600 pounds round and say are iron; 75 fathoms 3-inch rope.
107. These quantities do not include the material or labor employed in the bridges and plank walk across the marsh, and the boom, or the road and pier at the old engineer camp.
108. Table of average haul.
Materials. Tons. Miles Tons. Miles
Timber. 307 7 1/2 2,302 1
Lumber. 28 3 84 1
Sand and sand-bags. 812 1 1/1 1,218 1
Total. ... ... 3,604 1
109. Average pressure on the foundation of the battery, 513 pounds to the square foot.
110. Average pressure on the gun-deck, 123 pounds to the square foot, at rest.
111. The elevation of the gun, from 35 deg. to 37 deg.
112. Greatest range by Coast Survey map, 9,240 yards, or 5 1/4 miles.
113. Table of labor expended in construction of the Marsh Battery: 91 days' work of engineer officers, 1,384 days' work of engineer soldiers, 7,390 days' work of infantry, 172 days' work of four-horse teams, 93 days' work of boats.
114. During the night of the 10th of August, I tested Mr. Grant's calcium light, from the left center batteries, and found that the illumination was sufficient to be serviceable in siege operations. The light was not, however, used under my immediate observation, excepting in this first experimental trial.
115. During the night of the 16th of August, Captain F. E. Graef, Volunteer Engineers, made a covered way from the mortar batteries, in the rear of the first parallel, to the first parallel, and then extended it to the rear some distance, to include the Beacon House. the same day the roads to Black Island and the Marsh Battery, which had previously been built, were strengthened and widened by a working party under Captain S. C. Easton, Volunteer Engineers. This is represented in Figs. 5 and 6, Plate IV.
116. Captain Graef directed the construction of the road from the junction to the Marsh Battery, and was assisted by Lieutenant J. S. Baldwin, Volunteer Engineers.
117. On the night of the 17th of August, the Marsh Battery was ready for the gun, and Lieutenant Parsons, Volunteer Engineers, made their preparations to put the gun in place.
118. This was done by first carrying the timber parts, and then the iron work of the carriage, to the battery in boats, and landing them at the point previously prepared on the edge of the marsh, as shown in the drawings.