A majority of the lights of the first-class are housed in tall stone or brick towers, and a number of them stand upon very high ground. The light on Cape Mendocino glows from an eminence of 423 feet above the level of the sea, and is visible for twenty-eight miles. There are ten other lights whose elevation averages from 204 to 360 feet above sea level, and which are visible from twenty-one to twenty-six miles. The light at St. Augustine, Fla., is a fine example of its class. The strong and massive tower of brick rises 150 feet from the ground, and the light is reached by winding stairs. The apparatus for the light is twelve feet high and six feet through, and the lenses alone cost thousands of dollars. A powerful lamp in the centre of the apparatus sends its rays in all directions, the lenses being arranged at such angles as to gather the light and to send it out in parallel rays in the course desired. The cost of the St. Augustine lighthouse was $100,000.
Each lighthouse must have peculiarities of its own, so that both by night and by day the mariner can distinguish it from its neighbors, and thus guard against the mistakes that might otherwise prove fatal. The first result desired is accomplished by the use of fixed, revolving, blended, flash and intermittent lights, and as the timing of the second and the two latter classes is capable of great variety, it will be seen that the elasticity of the system is ample to meet all possible needs. To secure the second result desired the lighthouses are painted in different colors, and the application of the colors is varied in each instance. Some retain their natural colors, while others are painted black and white, or red and white; here broad horizontal bands alternating, and there slender spiral ones setting off the background of a sharply contrasting color. Again, the shape of the houses is varied, some being circular and others cone-shaped, some tall and others short, some square and others octagonal, while in many cases the shape and color of the keeper's dwelling nearby also help to make distinction easy. Thus the character of the light guides the sailor by night, and by day the form and color of the lighthouse give him welcome knowledge of his whereabouts.
The first lighthouses in this country were beacons, made by piling up stones, from the summit of which "firebales of pitch and ocum" were burned in iron baskets at night. It is a far cry from that time to this, and the construction of the lighthouse of the present day is, as has already been shown, a task demanding mechanical skill and engineering ability of the first order. A lighthouse on the mainland has few difficulties involved in its construction, but where the foundation is an isolated rock, a submerged reef, or a sandy shoal, the best resources of the engineer and mechanic are called into full play.
The lighthouse most difficult to build is that on the submerged rock or partly submerged rock. Race Rock Light, in Long Island Sound, belongs to this class. Portions of Race Rock are three and others thirteen feet under water. Diving-bells were used to level the foundations for the lighthouse, and the masonry and concrete under water were laid in the same way. The United States has two other lighthouses built on submerged rocks, Minot's Ledge in Boston harbor, and Spectacle Reef, on Lake Huron. The first lighthouse on Minot's Ledge was built above stout iron rods driven into the rocks. In April, 1851, there was a severe gale which lasted five days. On the third night of the storm the house was blown down and light and keeper went out together. Four years later a second structure was begun, this time with a foundation of masonry and concrete. Minot's is barely awash with the lowest tide, and so rare were the opportunities for work that three years were required to prepare the rock for the first course of stone, which was laid in 1857. In 1860 the structure was completed and has ever since stood proof against wind and storm.
Spectacle Reef lighthouse, near Mackinac, was built with the aid of a coffer-dam. A large wooden cylinder was constructed by banding long staves tightly together and towed out to the rock, where it was set up on the surface and the stones driven down into the uneven places. Then the crevices were filled with cement and the water pumped out. After this the rock was leveled and the limestone courses rapidly raised one above another. Spectacle Reef light stands eleven miles from land, and its base is seven feet under water.
Where there is a shifting shoal, whose unstable character no degree of mechanical or engineering skill can overcome, resort is had to the lightship. The United States has twenty-five of these vessels. Seven of them are employed off Massachusetts Bay to mark the Vineyard and Nantucket shoals, and a line of equal number lies along Long Island Sound stretching from Brenton's Reef to Sandy Hook. Four more are stationed off the New Jersey and Delaware coasts, one off Cape Charles, three off North Carolina, South Carolina and Georgia, and two off Louisiana and Texas. The life of a lightship crew, as will be told in another place, is a laborious and often a dangerous one.
The United States is divided into sixteen lighthouse districts, each one with its inspector and engineer. The former, drawn from the navy, inspects the lights under his jurisdiction at least every three months; the latter, a member of the Corps of Engineers, superintends the building, removal or renovation of the towers. Both are responsible to the Lighthouse Board, a body appointed by the President and composed of veteran naval officers of high rank, who are no longer fitted for active duty at sea.
The station of the third lighthouse district is on Staten Island, between St. George and Tompkinsville. Here over a hundred men are constantly employed and half a million dollars annually expended. From this station one hundred and eighty-nine lighthouses and beacon lights and seven lightships are maintained and supplied, while thirty-six day or unlighted beacons, thirteen steam fog signals, six electric light buoys, and five hundred and seven other buoys are looked after and kept in repair by the inspector and his assistants.