CAPE HATTERAS LIGHTHOUSE Sentinel of the Atlantic Graveyard By Frank E. Whitehouse, Associate Engineer, Richmond, Virginia HIS YEAR marks the 150th anniversary of the establishment of the National Lighthouse Foundation as an agency of the federal of the government and recalls the early history of the lighthouse. Actually, if the colonial period is taken into account, nearly 225 years have elapsed since the first lighthouse keeper took up his duties in what now is the United States. Since 1789, when 11 lighthouses already were in service, a continuous nightly duty has been performed all along the country's thousands of miles of coast and inland waterways where the warning lights must be kept burning. "Lights out" is a command never given in a light house until the sun heralds the new day. Like ships, the beacons and shore warnings have developed slowly throughout the centuries. It is another story of evolution. With the first step from oars to sails, ships ventured farther from home harbors -- although only for short voyages at first -- and some sort of guiding sign was needed to bring them safely back after night had overtaken them. Perhaps it was to direct returning fishermen, who during most of the day and into the night had spread their nets or cast their bone-tipped spears for food, that the women of the tribes of long ago built guiding bonfires at the beach or on a nearby hill. When we dip into the past to the days when sailors had to grope their way along dangerous dark shores with but a single bonfire or beacon to lead them the service performed by warning lights appears as one of the greatest maritime works ever undertaken.

More travel by water required more lights or fires on shore. As time went on and water-borne traffic became more common, towers were built along the coasts in order that the fires at their tops might be seen farther out at sea. One of the earliest written references concerning a lighthouse is that of a Greek poet of about 600 B. C., who mentioned a tower at Sigeum, near the site of ancient Troy. That fire tower or pharos was one of the first to be regularly maintained. The towers increased in number as their need became more apparent. In developing, they grew more and more similar in external appearance and the resemblance has continued to those that we know today.

One of the most famous lighthouses of all time was that of Pharos, at Alexandria, Egypt, completed in 247 B. C. The tower was more than 400 feet high, it is recorded, and the gleam of the fire at its top could be seen for 40 miles at sea. Modern lighthouse engineers do not agree with the latter claim, but are frankly skeptical that the light could have been visible for 20 miles. As for the height of the tower, we have the word of the ancients for that. In any case, it must have been an out-of-the-ordinary structure for it is included among the Seven Wonders of the Ancient World.

Most Americans are aware in a vague sort of way that lighthouses are there at the entrance to harbors and at intervals along the coast, but the existence of these important structures now is taken for granted, like the sun, moon and stars. They are always there. Yet, patient study, long labor and much money were required to establish the hundreds of lighthouses in service today in the United States. Some of them have served for a long, long time; others are as new as next year's automobile.

NE OF THE BEST known of these coastal guardians is a faithful sentinel of the Atlantic known in official language as Cape Hatteras Lighthouse. It ranks high in interest, but not as a marker for a busy harbor or as a tower standing picturesquely on a treacherous rockbound coast. Many miles from any commercially important port, it is situated on a sandy strip of land off the North Carolina coast, within the authorized boundaries of the proposed Cape Hatteras National Seashore, where one may watch the sunrise and set in the Atlantic. It commands special attention because it is today the highest brick lighthouse in the United States and because, for 66 years, it marked Diamond Shoals, one of the most hazardous points of the seaboard. Countless shipwrecks on these shoals have gained for them the aptly phrased designation, "the Graveyard of the Atlantic."

The dangers along this section of the coast are greatly increased because Hatteras is a control point in setting courses for seaboard and West Indian shipping. The shortest route for most vessels lies near the Cape, but the presence of Diamond Shoals and the Outer Shoals requires ships to keep almost 20 miles out. Northbound shipping finds a favorable current by staying in the Gulf Stream, while southbound traffic goes between the Stream and the coast where there is a southerly current. Many ships pass as close to the Cape as they can, but during storms there is the danger of being driven onto the shoals and eventually wrecked on shore.

The first lighthouse built at Cape Hatteras had been recommended by Alexander Hamilton in 1794 and was completed in 1798. It was a brown sandstone tower, octagonal in shape and 90 feet high, which soon proved to be too low and too poorly lighted to serve satisfactorily. Consequently, between 1867 and 1870 Congress authorized appropriations totaling approximately $67,000 for the construction of a new tower of greater height which was erected about 600 feet north of the old tower and, at that time, more than a mile from high tide mark.

Vertical and Horizontal Sections of the Cape Hatteras Lighthouse. (From the original drawings)

Although complete official information relative to the date on which work actually started and how many workers were employed is not available, it is known that a roadway one and one-half miles long had to be constructed to transport building materials to the site, and that the usual quarters for the men were provided. During 1869 the work progressed rapidly and by the end of April, 1870, the structure had reached a height of 103 feet. An isolated tower more than 190 feet high on a sandy shore requires a very stable foundation, especially when 80- or 90-mile winds are possibilities to be considered. The construction drawings which are available shed no light on the subject, but it was learned from a man, who as a boy had been employed on the construction, that the foundation was started by closely driving 50-foot pine piles over the entire area to be occupied by the tower. Then followed rubble masonry made with granite blocks starting at a point six feet below the ground. If this information is correct, all the foundation timbers are below water level at all times and therefore well protected and preserved. But whatever the foundation construction, there is now no evident signs of failure in the granite or brick masonry work that would indicate conclusively that unequal settlement has taken place.

The exterior of the lighthouse and a view of the lowlying coast are seen at the beginning of this article. (An idea of the great size of the structure may be gained by comparing it with the figure of a man in the left foreground). The base is octagonal and there is one entrance door on the side opposite from that shown in the photograph. The upper part is a frustrum of a cone. The interior is a round shaft 11 feet 6 inches in diameter from top to bottom in which is found an ingeniously designed spiral stairway leading to the lantern at the top. (See illustration on next page). Landings are placed on alternate sides and at each one of these is a window which provides ample natural light for the flights of stairs. One must climb nine flights of this spiral to reach the lantern room, or watchtower level, and one small ladder from the lantern room to the lantern gallery.

It will be noticed by studying the horizontal section of the tower, which is reproduced at the bottom of this page, that the enclosing wall is hollow through out most of its height. Radial walls of brick masonry tie the inner and outer walls together, indicating that the design was worked out carefully to balance safely the weight of the structure against the overturning power of the winds, and at the same time to provide economical construction.

LENS ASSEMBLY LENS FLAME SUPPORT AND OPERATING MECHANISM DRIVE GEARS AND GOVERNOR

The ascent of the tower and an examination of the intricate details of the lens and prism assembly, the rotating mechanism, the light mounting and related features -- all constructed by Henry Le Paute in Paris, France -- are educational experiences long to be remembered. The lens and prism assembly is shown in the top photograph on the opposite page. A large 24-sided bronze frame houses the individually ground bull's-eyes and prisms and revolves around the stationary light through operation of a governor-controlled train of gears energized by weights that travel vertically in the center of the tower (See middle and bottom photographs). Each day the weights must be cranked to the top by hand. The speed of rotation is governed so that at a distance in any direction at night one can observe a flash every sixth second. That occurs every time one of the bull's-eyes passes between the observer and the light. The duration of the flash is 1.4 seconds; the eclipse 4.6 seconds, it should be noted that the light burns steadily and does not flash on and off as most people suppose.

The rotating lens frame is protected from the elements by a heavy plate glass enclosure which is sufficiently large to allow walking space between it and the frame. A conical sheet copper roof covers the entire assembly. During the day the light proper must be protected by a curtain which is drawn around the outer surface of the lens frame and in addition by curtains on the inside of the outer enclosure. This precaution is taken to safeguard the lamp unit against the destructive heat of sun light concentrated by the lens as though through many powerful magnifying glasses.

The light has undergone several changes since it first was put in service December 16, 1870. The earliest lamp is said to have burned whale oil, the second kerosene; next was a mantle lamp, and finally one using electricity, Oil was stored in large tanks fitted into the arches of the lower part of the tower and electricity later was provided by a generating plant and storage batteries placed in a small building close to the base of the shaft.

At one time, possibly between 1870 and 1873, the top half of the lighthouse was painted red and the lower half white. In 1873 the official marking was established as alternate black and white spiral bands. There are two black bands and two white bands, each making one and a half revolutions about the tower. Every lighthouse has an officially designated marking, unlike that of any other unit of the system, just as it has its specific type of flash.

Threatened by the encroachment of the waves, which had cut away more than a mile of the shore and advanced almost to the base of the tower, Cape Hatteras Lighthouse flashed its last warning on May 15, 1936, and was abandoned by the United States Lighthouse Service for active night duty. The guardianship of the watery graveyard was taken over by a modern steel-frame tower erected a mile farther inland where its 80,000 candle power electric lamp projects a beam from an elevation of 166 feet above sea level. The new light is visible for 19 nautical miles. Nevertheless, during the day the familiar black and white spiral markings of the old brick tower still serve coastwise navigators in determining their position at sea. Meanwhile, the famous structure is in the custody of the National Park Service following its transfer November 9, 1936, and will continue to serve as a notable landmark for future visitors to the Gape Hatteras National Seashore.

Any story of Cape Hatteras would be incomplete without a mention of the Diamond Shoals Lightship, the most famous of the entire seaboard because it marks that dangerous spot just off the Cape. About 12 miles out from the Banks, the ship is anchored in a stretch of water that has hardly any equal anywhere for the frequency, suddenness and violence of its storms. It is significant to note also that near Gape Hatteras Lighthouse is one of the United States Navy's radio direction finder (radio compass) stations, the most recent development by which a ship at sea may determine its position with accuracy.

Altogether, it is gratifying to observe that the Cape Hatteras National Seashore will be provided with excellent examples of four important steps in the history of coastwise navigational aids: (1) the 69-year-old lighthouse where four advancements in the source of light are recorded; (2) the modern lighthouse of skeleton design; (3) the anchored lightship, and (4) the naval radio compass. These features combine to make a valuable educational exhibit of man's progress in the long struggle to protect himself and his ships and cargoes against the mighty powers of the sea.