UNION CORRESPONDENCE, ETC.

NEAR WILMINGTON, DEL., December 31, 1863.

Captain HENRY S. TAFFT,

Signal Officer, U. S. Army, Washington City, D. C.:

MY DEAR CAPTAIN: It had been my intention before leaving Port Royal to express to you, through the commanding general, my high appreciation of the labors of the army signal corps in the Department of the South, so far as they related to the naval force under my command. The system itself elicited the highest commendation, and its adaptation ashore and afloat became every day more striking and valuable.

I was first impressed with its superiority on our passage down with the "expeditionary corps," for it enabled me to keep up a ready communication with the army transports, and I am convinced that but for directions which I gave to several vessels--and which I could only have transmitted by these signals--on the eve of a dangerous gale we encountered, we should have experienced serious disaster from collision. You were also present when, soon after, the excellence of the code was further tested by the rapid intercommunication between the squadron of gunboats in the Coosaw River and the army on shore during the battle of Port Royal Ferry, under the lamented Stevens. Commander C. R. P. Rodgers, who commanded the naval force on the occasion, closes his official report to me in the following words:

Lieutenant Cogswell, a signal officer of the army, was directed to report to me for duty and furnish me with the means of constantly communicating with General Stevens, with a facility unknown to the naval service. I take this opportunity of recommending that the code of signals invented by Major Myer be at once introduced into the navy.

While thus expressing my unqualified approbation of this beautiful system, which I have had occasion to use so frequently, both by day and night, I deem it my duty to state how efficiently the signal officer of the army performed his duties while on board the ships of my squadron, evincing on all occasions conspicuous zeal.

To yourself, captain, as the senior signal officer int he department and to your untiring attention to promote everywhere the efficiency of the public service, much of this was due, and I shall always recur to our official and personal intercourse with great satisfaction.

I am, my dear captain, yours, respectfully,

S. F. DU PONT,

Rear-Admiral, U. S. Navy.