directed in your verbal instructions, viz, the propriety of occupying and holding the first Tybee Island, and the practicability (and, if deemed practicable, the best method) of reducing Fort Pulaski. I deem the reduction of that work practicable by batteries of mortars and rifled guns established on Tybee Island. I think it probable that a nearer position on firm ground (though very shallow, and therefore ill-adapted to mortar and sunken batteries) can be found on the island west of Tybee. I would establish these batteries from 20 to 25 yards apart, one gun or one mortar in each, behind the ridge of sand on the shore, westward from the light-house. I would sink the mortar batteries as low as the water would permit, and the guns sufficiently low to leave a high parapet in front. On the sides and rear of each I would have a high mound of earth, and I should cover each with a horizontal bomb-proof shelter of logs, covered with earth, and supported by logs planted vertically in the ground. The embrasures for the guns should be deep, narrow, and of very little splay. I estimate that after once obtaining the range five-eights of the shells from mortars can be lodged inside of the fort. I would have enough mortars to throw one shell a minute into the fort, and as many guns as mortars. The batteries should operate day and night. For landing the ordnance required for these operations I would have built two or three broad flat-bottomed bateaux or scows, such as are commonly used on rope ferries. I think these could be built here.
There are now probably at Fort Pulaski 700 good troops. About 200 landed yesterday, and the Navy officers informed me that at least 500 have entered the fort within the last three days, while some (probably raw recruits or portions of the Home Guard) have gone away. It may be their design to land on Tybee and hold the west end of it, to prevent the erection of batteries against the fort. I therefore recommend the immediate occupation of Tybee Island by one good regiment until the question of attempting the reduction of Fort Pulaski be determined.
I learned while at Tybee that offers have been made by negroes to burn two of the principal bridges on the railroad between Charleston and Savannah. One of these bridges is said to be nearly two miles long. In a military point of view its destruction would be of great value to us, and I recommend the subject to your attention.
Very respectfully, your obedient servant,
Q. A. GILLMORE,
Captain, and Chief Engineer Expeditionary Corps.
Approved, and I fully concur in the plan of Captain Gillmore for reducing Fort Pulaski, except possibly the use of rifled guns, until their effect has been more fully tested. All that can be done with guns is to shake the walls as far as practicable in a random manner. As the nearest distance at which batteries can be constructed is 1 1/2 miles from Pulaski, if rifles guns are found to be non effective at that distance, which is certain if it is discovered that the shot will not strike point foremost, then I think that a few 10-inch columbiads may be used in addition to the mortars, for they may be employed with solid shot for direct fire against the walls or as mortars for the interior.
It is impracticable to establish batteries nearer Pulaski than above stated, whether on Tybee or the island west of it. A few days before this reconnaissance I drew the fire of the fort, and ascertained that their casemate guns came a little short of the shore at the position of the fort