The history of our ironclads, from their first placing on the stocks, to the present time, when Charleston engrosses them all, is read with avidity, but few know anything of life on our blockaders, or, thinking there is not the dignity of danger associated with them, take little or no interest in what they may chance to see concerning them. Those who have friends on blockade duty may be interested to know more of their daily life than can be crowded into the compass of home letters, and the writer, one of the squadron off Wilmington, would constitute himself historian of the doings of at least one ship of the fleet. Wilmington, Charleston, and Mobile, alone remain of all the rebel ports, but it is with the first we have to do--where it is, how it looks, &c. Right down the coast, some 450 miles from New York, and a hundred or more from the stormy cape of Hatteras, you will see the river which floats the merchandise to and from the docks at Wilmington, emptying into the ocean at Cape Fear, from which it takes its name. The river has two mouths, or rather a mouth proper, which opens to the south of the cape, and an opening into the side of the river, north of the cape called New Inlet. Perhaps more seek entrance by this inlet than the mouth, which is guarded by Fort Caswell, a strong, regularly built fort, once in Union hands, mounting some long-range English Whitworth guns. One other fort has been built here since the commencement of the war. This inlet is guarded by a long line of earthworks, mounted by Whitworth and other guns of heavy caliber. Wilmington lies some twenty miles from the mouth, and fifteen north of New Inlet. One great characteristic of this coast is the columns of smoke, which every few miles shoot up from its forests and lowlands. All along the coasts may be seen mounds where pitch, tar, and turpentine are being made. These primitive manufactories for the staple of North Carolina are in many places close down to the water's edge, whence their products may easily be shipped on schooners or light-draft vessels, with little danger of being caught by the blockaders, who draw too much water to make a very near approach to shore. So much for the coast we guard; now for ourselves.