e whole progress of the work.

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.

FOOTNOTES:

[Footnote 5: Lines written by Sir Walter Scott in the Album of the
Bell-Rock Lighthouse, when he visited it in 1814.]

CHAPTER VIII.

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