Department of the Gulf.-In this department Captain William B. Roe, chief signal officer, with his whole party, reported for duty to Major-General Franklin for the Sabine Passa expedition September 1, 1863.

On September 8 the gun-boats attacked the fort at Sabine Pass. First Lieutenant H. C. Dane was stationed on the Sachem, and Second Lieutenant J. W. Dana on the Clifton. These officers were subjected to a very severe fire from the enemy's works, they having occupied a very exposed position to enable them to communicate with each other and also with General Franklin.

During the engagement constant communication by signals was maintained between General Franklin's headquarters and the gunboats. The Sachem and Clifton were compelled to surrender, and 2 officers and 4 enlisted men were taken prisoners. Immediately upon their surrender orders were sent by signals to the different generals to get under way and move to the mouth of the Mississippi River and there await orders.

First Lieutenant T. S. Seabury is reported as entitled to much credit for the faithful manner in which he performed his duty, and also for remaining on board the steamer Crescent when others abandoned her and rendering great assistance in getting her off the bar. Meritorious mention is also made of First Lieutenant S. M. Eaton. Captain Roe says in his report of these operations:

The brave and gallant conduct of Lieutenants Dane and Dana can hardly be overestimated. Never have I seen signal subjected to as hot a fire as were they, and in no case were they found absent from their posts of duty.

In the Teche campaign, which immediately followed the Sabine Pass expedition, Captain Roe lost First Lieutenant J. L. Hallett, Second Lieutenant G. R. Herbert, and 3 enlisted men taken prisoners.

In the Texas coast expedition, from November 1, [1863,] to January 1, 1864, there were transmitted over 500 official messages. During the prevalence of fierce weather there were days when the only available communication between the army and fleet was by signals.

First Lieutenant T. S. Seabury, by incessant application, impaired his eyesight to such a degree as to necessitate his withdrawal from military service.

First Lieutenant S. M. Eaton was in charge d from Major-General Banks the following Honorable mention:

In our recent movements upon the coast of Texas it was the only means of communication (the Signal Corps) between the inland by as and the coast, and without the assistance of the signal officers it seems as if we would sometimes have been deprived of the power of communication. The importance of its services in this care can hardly be overestimated. The same is true of its services on land.

Especial attention is invited to the establishment of signal communication in January between Fort Jackson and the Head of the Passes of the Mississippi River. This line commanded all entrances to the river.

About this time the mysterious departure of steel-clad steamers from England, the reported rendezvous of rebel cruisers in the gulf, and bold sorties from Mobile to the Passes of the Mississippi, with the consequent insecurity of the telegraph line upon the river-bank, combined to make signal communication at the points specified of vital importance. This line was continued for several weeks, and was so thorough that information could at any time have been communicated by either flags, torches, or rockets, of the appearance of any strange sail or fleet off the mouth of the river, or in its passes.