1. These, with Buoys, and Beacons, are a necessary practical supplement to the labors of the Coast Survey. Buoys and Beacons indicate the shoals, or dangerous rocks and reefs beneath the surface of the water, in the daytime; while light houses indicate the same, and show the mariner the bearings of the land, in the night; and, by studying, in connection with these, the charts of the coast supplied by the Coast Survey, he may make his way as securely in the night or day through the concealed dangers of the treacherous waters as a landsman along a beaten highway. They are way-marks along the sea coast, at the entrance of harbors, and on lakes and rivers. They speak a language very well understood by the seaman; and are invaluable for the protection of his vessel from the dangers of the Deep. 2. Keepers are appointed by the government to keep them in repair, and to see that they are properly lighted every night. We have no means of knowing the number of these useful establishments, but there must be several hundred of them; for we have more sea coast than any other nation upon the globe, with a still greater length of lake and river shore. They are located at prominent points, and at dangerous places, all along the extensive lines of coast and shores. 3. To the end that light houses should be constructed and kept in repair, and that competent men might have the whole matter in charge, a law of 1852 authorized the President to appoint two officers of the navy of high rank, one officer of the corps of engineers of the army, one officer of the topographical engineers, and two civilians of high scientific attainments, to form a LIGHT HOUSE BOARD for the United States. This board is attached to the Treasury Department, and the Secretary of the Treasury superintends its operations. The board has in charge the building, illumination, and inspection of light houses, light vessels, buoys, beacons, sea marks, and their appendages. 4. The Secretary of the Treasury is president of the board, and may convene them whenever he deems it necessary. The law makes it the duty of the board to divide the whole of the sea, gulf, and lake coasts, into light house districts; not exceeding 12 in number. An officer of the army or navy is assigned to each district, as a light house inspector. They have the control of everything relating to light houses, light ships, buoys, beacons, or other means of directing vessels in and out of port, or of guiding them while sailing along the coast in the night.