over which the iron-tongued wood-floors are laid.

The several rooms are provided with fire apertures, fitted with oak
sashes filled with plate-glass. The approach to the doorway, which is
about ten feet above the level of the sand, is by means of
stone-steps; ladder-irons are also provided in the event of the
stone-steps being carried away by a hurricane.

Over the entrance is a large tablet of iron supported by two smaller
ones; and on them, on bas-relief, are inscribed the date of erection
(1842), the names of the commissioners, of the engineer, founder, &c.

The whole of the castings were executed at the foundry (late Bramah
and Robinson's) at Pimlico, and put together in the yard of the
manufactory, prior to their removal to Jamaica, where the work was
re-erected by a derrick and crab from the inside, without the aid of
any external scaffolding.

It is said that the whole expense of the lighthouse, including the
passage over the Atlantic, did not exceed seven thousand pounds, and
that the entire weight of the iron-work is about one hundred tons. The
masonry was also prepared in this country, which (from the absence of
building-stone in Jamaica) was found to be more economical than if the
work had been done on the spot. Mr. Grove, as clerk of the works, and
two labouring engineers, who had attended to the execution of the work
in England, were sent out for the purpose of erecting the lighthouse,
and the necessary apparatus upon the site which had been selected. The
elevation of the lighthouse above the level of the sea is one hundred
and three feet.

Since the completion of this lighthouse, Mr. Gordon has been employed
by the Ordnance Office to furnish designs and specifications for a
tower on the same principle, but of larger dimensions and improved
details, which is to be erected on Gibbs' Hill, in the island of
Bermuda.

CHAPTER IX.

THE LIGHTHOUSE SYSTEM.

Imperfect Illumination of the old Lighthouses--First
Improvements--The Argand Lamp and Reflecting Mirrors--Revolving
Lights--The Catoptric System--Varieties of Lights--The Dioptric
System--Its Details--Introduction of this Method into Great
Britain--Comparison of the two Methods--The Drummond and Voltaic
Lights--Gurney's Lamp--Captain Basil Hall's Experiments--Ventilation
of Lighthouses.

Since there is something more or less common in the modes of lighting
and in the general economy of all lighthouses, a