sidered practically harmless against exposed masonry, must be at least trebled, now the rifled guns have to be provided against.

The inaccuracy of the fire of the 13-inch mortars has already been adverted to. Not one-tenth of the shells dropped inside of the fort. A few struck the terre-plain over the casemate arches, but, so far as could be observed by subsequent inspection from below, without producing any effect upon the masonry. Whether they penetrated the earth work to the roofing of the arches was not ascertained.

Two or three striking in rapid succession into the same spot over an arch might be expected to injure it seriously, if not fatally. Such an occurrence would, however, be rare indeed. Against all, except very extraordinary casualties, it would be easy for a garrison to provide as they occurred, by repairing with sand bags or loose earth the holes formed in the terre-plain by shells.

We may therefore assume that mortars are unreliable for the reduction of a good caseated work of small area, like most of our sea-coast fortifications.

As auxiliary in silencing a barbette fire, or in the reduction of a work containing wooden buildings and other exposed combustible material, mortars may undoubtedly be made to play an important part.

For the reduction of fortified towns or cities, or extensive fortresses containing large garrisons, there is perhaps no better arm than the mortar, unless it be the rifled gun, firing at high elevations.

To the splinter-proof shelters constructed for the seven advanced batteries I attribute our almost entire exemption from loss of life. We had 1 man killed by a shell from one of the mortar batteries outside the fort, which was the only casualty.

The demoralizing effect of constant and laborious fatigue duty upon the health and discipline of troops, particularly upon such as are unused to the privations of war, like our volunteers, who can but slowly adapt themselves to the stinted comforts of a campaign, is a subject which demands the earnest attention of commanding officers in the field.

Upon regular troops, to whom the drill in their special arm has to a certain extent become a second nature, who are accustomed to the vicissitudes of the field and familiar with expedients and make-shifts to secure comfort, the bad effects of excessive labor and constant interruption of drill are of course less apparent.

With the average of our volunteer regiments every alternate day should be devoted to drill, in order to keep them up to a fair standard of efficiency.

Very respectfully, your obedient servant,

Q. A. GILLMORE,

Major-General Volunteers.

To the ADJUTANT-GENERAL U. S. ARMY,

Washington, D. C.

Numbers 6. Report of Surg. George E. Cooper, U. S. Army.

MEDICAL DIRECTOR'S OFFICE, DEP'T OF THE SOUTH,

Hilton Head, S. C., April 14, 1862.

SIR: Herewith inclosed I transmit the list of casualties which occurred among the United States forces during the attack on Fort Pulaski, Ga.