Lightships and Lighthouses. Frederick Arthur Ambrose Talbot
Photo, Paul, Penzance.
THE EDDYSTONE, THE MOST FAMOUS LIGHTHOUSE OF ENGLAND.
To the right is the stump of Smeaton’s historic tower.
From the entrance, which was about 15 feet above high-water, a central well, some 5 feet in diameter, containing a staircase, led to the storeroom, nearly 30 feet above high-water. Above this was a second storeroom, a living-room as the third floor, and the bedroom beneath the lantern. The light was placed about 72 feet above high-water, and comprised a candelabra having two rings, one smaller than, and placed within, the other, but raised about a foot above its level, the two being held firmly in position by means of chains suspended from the roof and secured to the floor. The rings were adapted to receive twenty-four lights, each candle weighing about 2¾ ounces. Even candle manufacture was in its infancy in those days, and periodically the keepers had to enter the lantern to snuff the wicks. In order to keep the watchers of the lights on the alert, Smeaton installed a clock of the grandfather pattern in the tower, and fitted it with a gong, which struck every half-hour to apprise the men of these duties. This clock is now one of the most interesting relics in the museum at Trinity House.
The first stone of the tower was laid on a Sunday in June, 1757, as the date on the block indicates; and although work had to be pursued fitfully and for only a few hours at a time between the tides, in the early stages, Smeaton seized every opportunity offered by the wind and sea to push the task forward. For four years the men slaved upon the rock, and, although the mechanical handling appliances of those days were primitive, the tower was completed without a single mishap. The solidity of the structure, and its lines, which, as the engineer stated, would offer the minimum of resistance to the Atlantic rollers, but at the same time would insure the utmost stability, aroused widespread admiration, for it was felt that the engineer had triumphed over Nature at last. Many people expressed a desire to see how the tower would weather such a storm as carried away Winstanley’s freakish building, especially as, in a roaring sou’-wester, the waves hurled themselves upon the ledge to wreathe and curl upwards to a point far above the dome, blotting the light from sight. The supreme test came in 1762, when the lighthouse was subjected to a battering and pounding far heavier than any that it had previously known. But the tower emerged from this ordeal unscathed, and Smeaton’s work was accepted as invulnerable.
Photo, Paul, Penzance.
A THRILLING EXPERIENCE.
Landing upon the Eddystone by the crane rope during a rough sea.
The lighthouse had been standing for 120 years, when ominous reports were received by the Trinity Brethren concerning the stability of the tower. The keepers stated that during severe storms the building shook alarmingly. A minute inspection of the structure was made, and it was found that, although the work of Smeaton’s masons was above reproach, time and weather had left their mark. The tower was becoming decrepit. The binding cement had decayed, and the air imprisoned and compressed within the interstices by the waves was disintegrating the structure slowly but surely. While there was no occasion to apprehend a sudden collapse, still it was considered advisable to take precautionary measures in time. Unfortunately, it was not feasible to strengthen Smeaton’s tower so adequately as to give it a new lease of life, while lighthouse engineering had made rapid strides in certain details since it was completed. Another factor to be considered was the desire for a more elevated light, capable of throwing its rays to a greater distance.
Under these circumstances it was decided to build a new tower on another convenient ledge, forming part of the main reef, about 120 feet distant. Sir James Douglass, the Engineer-in-Chief to Trinity House, completed the designs and personally superintended their execution. The Smeaton lines were taken as a basis, with one important exception. Instead of the curve commencing at the foundations, the latter comprised a perfect cylindrical monolith of masonry 22 feet in height by 44 feet in diameter. From this base the tower springs to a height which brings the focal plane 130 feet above the highest spring-tides. The top of the base is 30 inches above high-water, and the tower’s diameter at this point being less than that of its plinth, the set-off forms an excellent landing-stage when the weather permits.
The site selected for the Douglass tower being lower than that chosen by Smeaton, the initial work was more exacting, as the duration of the working period was reduced. The rock, being gneiss, was extremely tough, and the preliminary quarrying operations for the foundation-stones which had to be sunk into the rock were tedious and difficult, especially as the working area was limited. Each stone was dovetailed, not only to its neighbour on either side, but below and above as well. The foundation-stones were dovetailed into the reef, and were secured still further by the aid of two bolts, each 1½ inches in diameter, which were passed through the stone and sunk deeply into the rock below. The exposed position of the reef enabled work to be continued only fitfully during the calmest weather, for often when wind and sea were quiet the rock was inaccessible owing to the swell. Upon the approach of bad weather everything was made fast under the direct supervision of the engineer—a man who took no chances.
From the set-off the tower is solid to a height of 25½ feet, except for two fresh-water tanks sunk in the floor of the entrance-room, which hold 4,700 gallons. At this point the walls are no less than 8½ feet thick, and the heavy teak door is protected by an outer door of gun-metal, weighing a ton, both of which are closed during rough weather.
The tower has eight floors, exclusive of the entrance; there are two oilrooms, one above the other, holding 4,300 gallons of oil, above which is a coal and store room, followed by a second storeroom. Outside the tower at this level is a crane, by which supplies are hoisted, and which also facilitates the landing and embarkation of the keepers, who are swung through the air in a stirrup attached to the crane rope. Then in turn come the living-room, the “low-light” room, bedroom, service-room, and finally the lantern. For the erection of the tower, 2,171 blocks of granite, which were previously fitted temporarily in their respective positions on shore, and none of which weighed less than 2 tons, were used. When the work was commenced, the engineer estimated that the task would occupy five years, but on May 18, 1882, the lamp was lighted by the Duke of Edinburgh, the Master of Trinity House at the time, the enterprise having occupied only four years. Some idea may thus be obtained of the energy with which the labour was pressed forward, once the most trying sections were overcome.
Whereas the former lights on this rock had been of the fixed type, a distinctive double flash was now introduced. The optical apparatus is of the biform dioptric type, emitting a beam of some 300,000 candle-power intensity, which is visible for seventeen miles. In addition to this measure of warning, two powerful Argand burners, with reflectors, were set up in the low-light room for the purpose of throwing a fixed ray from a point 40 feet below the main flashing beam, to mark a dangerous reef lying 3½ miles to the north-west, known as Hand Deeps.
When the new tower was completed and brought into service, the Smeaton building was demolished. This task was carried out with extreme care, inasmuch as the citizens of Plymouth had requested that the historic Eddystone structure might be re-erected on Plymouth Hoe, on the spot occupied by the existing Trinity House landmark. The authorities agreed to this proposal, and the ownership of the Smeaton tower was forthwith transferred to the people of Plymouth. But demolition was carried out only to the level of Smeaton’s lower storeroom. The staircase, well and entrance were filled up with masonry, the top was bevelled off, and in the centre of the stump an iron pole was planted. While the Plymouth Hoe relic is but one half of the tower, its re-erection was completed faithfully, and, moreover, carries the original candelabra which the famous engineer devised.
Not only is the Douglass tower a beautiful example of lighthouse engineering, but it was relatively cheap. The engineer, when he prepared the designs, estimated that an outlay of £78,000, or $390,000, would be incurred. As a matter of fact, the building cost only £59,255, or $296,275, and a saving of £18,000, or $90,000, in a work of this magnitude is no mean achievement. All things considered, the Eddystone is one of the cheapest sea-rock lights which has ever been consummated.
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