During the fourth season, the operations were retarded by several untoward accidents. The wind and the waves sometimes destroyed in a moment the labour of weeks; but by dint of skill and untiring patience and industry, they succeeded by the month of November in completing the sixteenth course, which raised the building to the height of about twenty feet.
The fifth year was particularly unfortunate. The whole of the masonry having been completed, the coast was visited in November with a gale of wind, accompanied with a heavy swell of sea, which washed down the upper part of the building, and reduced it to the height of the fifth course, which formed part of the fourth year's work. It was therefore determined to modify the original design of the work. Instead of completing this beacon with masonry, and providing the machine and large bell, which was to have measured five feet across the mouth, to be tolled by the alternate rise and fall of the tide, it was now determined to erect six columns of cast iron upon the remaining courses of masonry, to terminate in a cast iron ball of the diameter of three feet, formed in ribs, elevated about twenty-five feet above the medium level of the sea. This beacon was completed in September 1821.
[Footnote 5: Lines written by Sir Walter Scott in the Album of the Bell-Rock Lighthouse, when he visited it in 1814.]
LIGHTHOUSES ON SAND AND CAST-IRON LIGHTHOUSES.
Floating Lights--Objections to--Mitchell's Screw-moorings-- Experiments on the Maplin Sand--Foundation--Erection of Screw-pile Lighthouse--Details of the Wyre Lighthouse--Proposed Lighthouse on the Goodwin Sands--Metallic Lighthouses--Advantages of Metal over Stone--Details of Cast-iron Lighthouse at Morant Point, Jamaica.
Those dangerous approaches to a coast which, from the nature of the soil, have not till very lately admitted of the erection of a permanent lighthouse, are usually indicated to the navigator by floating lights; but these being nothing more than large lanterns suspended in the rigging of a vessel, necessarily possess but feeble illuminating power. This power is still further diminished in a gale of wind, when it is most wanted, by the pitching and floundering about of the vessel: every now and then she is submerged in the trough of the sea, covered with spray and drift, or, what is most to be dreaded, she is liable to be blown away from her moorings; an accident which has been productive of the most disastrous consequences to life and property.