The armament of the breaching batteries first erected against Fort Sumter, as I have before enumerated in my first report, consisted of one 10-inch, six 8-inch, nine 100-pounder Parrott rifles, and two 80-pounder Whitworths.

In the second bombardment, commencing the 26th of October, there were in position one 10-inch, two 8-inch, and nine 100-pounder rifles, one 10-inch columbiad, and four 10-inch seacoast mortars; and subsequently, at the date of this report, there were added eight 10-inch seacoast mortars, two 10-inch siege mortars, and two 13-inch seacoast mortars.

The garrisons of these batteries were made sufficiently strong, so that each gun had three reliefs. A relief consisted of a full detachment of cannoneers, with 2 and 3 men for service in magazine with each relief.

A tour of duty for a relief with the breaching batteries was four hours on and eight off. The relief, however, which came on at 8 o'clock in the evening generally remained till 4 next morning when no night firing took place.

The firing from the batteries against Wagner not being so rapid or so constant as from the other batteries, men served in them twelve hours on and twenty-four off.

It was quite a task for the men simply to go to and from the batteries, when added to the labor they performed at their guns. The numerous guns of the enemy which encircled us swept the ground for a specie of nearly a mile in rear of our batteries. Throwing our camps necessarily beyond it, this distance had to be passed over at every tour of duty.

It very soon became manifest, after our fire upon Sumter had opened, that unremitted attention to the service of these rifled guns in every particular of detail would be imperative to insure that accuracy necessary for success.

The precision of fire of the Parrott rifles was remarkable, probably excelling any artillery ever before brought on to the field in siege operations; but it was quickly fund that, in the field, where preparations are not always very complete and necessary appliances are scanty, many elements entered to disturb this accuracy, more particularly when the power of the gun came to be taxed, as in the range we wished to attain in our fire upon Sumter; that errors at this distance multiplied in these guns very rapidly, and therefore grater attention than that ordinarily given to a smooth-bore gun would be required to eliminate them. To this end, battery commanders were required to be present at all firing, and were constantly instructed and strictly enjoin din the observance of everything connected with the service of the piece which it was thought might in any way affect its accuracy.

It was expected that the 100-pounders and the 8-inch would fire with a rapidity of about one discharge in eight minutes, but the result of the first day's firing showed that this time was greatly exceeded. Afterward, however, when offices and men had more experience, and the machinery of the carriages had worked smooth, the firing was more rapid, and, when necessary, the 100-pounders could be fired once in five minutes, and the 8-inch once in seven and eight minutes. The 10-inch was never fired faster than once in ten minutes, but could be served with facility for a day at a rate of once in eight minutes.

There is an immense labor incurred in the handling of the projectiles