same time my duty to explain to you the reasons which render the continued and urgent calls for laborers on the Mobile defenses an absolute necessity.

Two forts (constructed at a period when neither the penetration of a 200-pounder or 300-pounder Parrott shell nor the resistance offered to solid shot by an iron-clad vessel were known to the engineers), a few wooden gunboats, and several rows of piles, not reaching across the whole distance of 3 miles, form as yet the only defense of the main entrance to Mobile Bay. Any Ironsides or Dictator can, at any hour, pass the forts, cut them off from all supplies, and render herself undisputed mistress of Mobile Bay.

The undersigned urges the construction of a strong battery between Forts Morgan and Gaines, as well as the obstruction of the main channel by a system of sawyers, ropes, and torpedoes.

His plans have been approved by the major-general commanding, by Admiral Buchanan, and by the best engineers in the service, Generals Beauregard and Gilmer included; but their execution, though it would require comparatively only a short time, has had to be postponed for want of the necessary labor, and transportation, and most precious time is thus being lost irreparably.

Fort Powell (Grant' Island), with a battery projected for Cedar Point, will render Grant's Pass safe against any attack by water. Unfortunately, Fort Powell is not completed, the new battery not commenced yet, for want of labor an transportation.

The two most important batteries-McIntosh, formerly Spanish River, and Gladden, formerly Pinto-are being reconstructed entirely.

Your Excellency may form an idea of the difficulties in our way from the fact that over 120,000 cubic yards of earth are required for the construction of the parapets, bomb-proof traverses, &c.; that the earth has to be brought from a point over 10 miles distant from the batteries, and that the engineer department has only four small flats and one steamboat at its disposal to do all this work; yet excellent progress is being made by pushing on the work day and night.

Batteries Huger and Tracey (which serve as protection to the Appalachee and Tensas Rivers) will equally require some additional work before they can be considered efficient works.

Much progress has been made toward the completion of the city intrenchments, but much labor is required to render Mobile safe against a land attack. The construction of the heavy new works would require at least 3,500 hands for three months. The engineer department had yesterday only 530 hands at work on Redoubts A and B, the only ones of the nine new redoubts that could be commenced.

Recapitulation of work to be done yet:

1. Citadel of Fort Morgan to be changed into a wide, covered bombproof.

2. A new battery to be built on the west bank of the channel between Forts Morgan and Gaines.

3. Obstructions to be placed in the main channel.

4. Fort Powell to be completed.

5. A new battery on Cedar Point to be built.

6. Batteries McIntosh and Gladden to be completed.

7. Batteries Huger and Tracey to be strengthened.

8. The inner line of redoubts to be completed.

9. Redoubts A and B to be completed.

10. Seven new redoubts to be built.

11. A citadel-very heavy work-to be built.