4,
to this dimension . The floor of the light-
room is 188 feet. 6 inches, above the mean sea level, which would make the focal plane 200 feet, and at this elevation it is sought that the lenticular apparaties should throw
-every ray of light as complete- ly as possible to the
horizon!? 8. The roof of the lanterns should be specially designed to ward off radiation and to ensure extra protection from
Porcibly powerfect effects of a tropical sun. with this view, a double roof might be designed capable of withe tanding
The force
of typhoons .
The
"The Ventilation of the lantern will also have to be specially considered and the space allowed for the escape of and foul
of heated
air at the apex of the rook should be not less than 150 inches.
10. For the design and execution of all in
and other metal work it onust be borne
in enind that the Cape L'Aquilar light house will be subjected almost yearly to the full force of the hurricanes pre-
-valent in these latitudes, and which are perhaps the most
The most fearful on record . It
will.
-."%EN-V---- An
307
will therefo & be essential to ensure the utmost strength and
4th and solidity in every
portion of the work even to the smallest detail. Horns panes should be
be provided. with the lantern capable of being put up on the shortest notice in the event of __
11. As it may possibly,
arise in endeavour:
ing to provide sufficient strength in the wrought iron standards of the lantern,
that the thickness
of them
may greatly increase the interception of light and
thereby diminish the power of the light be worth while to consider whether the
sensibly
may required stability may
by arrang
not be attained
anging the frame with a greater in
-clination inward, and
by rivetting
the
so as to
It so
so the
whole together in here of bolting
render it more,
more rigid. If
s
it
recessary rivets should accompany the iron work. 12. I would I further be advisable afters.
the structure has been put together at the
manufactury to paint corresponding marker on the different pieces which fit into one another; this would facilitate the putting
it together in Title which will be almost
entirely
of it