The daily union. [volume] (Washington [D.C.]) 1845-1857, 1846-12-02
THE DAILY UNION
LIGHTHOUSE SYSTEM.

Uctu III puolS PNPN''p :" W" fNIHff
made by the Secretary Of the Treasury, towards the
close of the session, upon improvements In the
lighthouse system and collateral aids TO navigs-
ion." The secretary has taken great pains 10 col
lect the best lights from tho systems adopted in Eu-
rope, by means Of the two commissioners whom
he despatched during the last summer to Europe.
Mr.. Walkers report, accompanied by the various
documents which they returned to him, extend to
27e pages in the printed form. IL is impossible to
lay the whole before our resders, and we are COM
PEELED eonfne ourselves to the luminous report Of
the secretary showing in general terms the systems
which have been adopted abroad, with their pecu-
lar merits. He has taken much pains In presenting
the peculiar points ofthe subject, particularly the lens
system oflhe French, to the considerations Of Con-
gress. We now lay this report before our readers;
REPORT , -
OF the Secretary Of the Treasury, on improvements Ia
The lighthouse system and collateral aids 10 napiga-
lion.
1REAsURY DEPARTMENT,
...." August S, 1886.
STA: have the honor to submit TO the Senate Of
the United States a report in relation 10 improve
ments in the lighthouse system OF the United
States, and in collateral aids TO navigation.
Ihe Improvements OF our Ol HSnl-nouscs
has attracted at different times the attention Of Con-
gress and ofthe Executive. Impressed with the ne
cessty for obtaining fu information IN regard 10 the
improvements alleged 10 have been made in Europe,
en1nnatng principally from France, applied in June
last to the Navy Department foe the detail oflwo of
fcers who might, under Instructions from hisdepart-
ment visit the countries into which the improved sys
tenn had been introduced, make themselves practical
ly acquainted with the different parts, and establish
the necessary comparison with our own. Lieu
tenants Thornton A. Jenkins and Richard Bache
were detailed for this service, and visited some OF
the principal lights on the shores of the Baltic and
North seas the coast Of England, Ireland and Scot
land and the establishments for the construction OF
the new lighting apparatus in France; collecting,
with care, zeal, and intelligence the full and varied
information upon this important subject, and others
connected with ii, which is so ably presented in
their report to this department. H.. ...
The subjects are systematically treated in their
report and II will be necessary merely to refer here
to suggestions for the improvement Of our system,
which meet my hearty concurrence
In countries where the system Of lighting Is
good a general plan for the classification OF lights
selection Of Sites construction OF the lighthouses
and apparatus, and inspection, has been adopted. or
improvements have been slowly introduced, under
the directions Of existing authorities. The most
perfect system in Europe is the result OF the former
plan; and il must be obvious, that, for a growing
country like ours, other can secure, the great
er part Of the coast due attention to the wants Of
commerce and navigation. LID.
| The unequal distribution Of lights upon different
important parts Of coast proves this, and shows
how desirable il is that some general plan should be
fallen upon by which the claims of different parts OF
| the country might be duly considered, a light pro-
vided wherever IL is desirable to navigation, and
penditure saved when no sach necessity exists
that when a lg hit house decided TO be necessa-
nv, the site Of the buildings should be properly Sc
leeted the buildings properly constructed as TO
combine stability and economy; all the accessories,
| az store-houses for oil and for lighting apparatus,
for fuel, and the like, properly arranged; that the
lighting apparatus should be Of the most approved
Kind and construction and so placed as 10 illumi-
nate the required parts Of the horizon without waste
| that the lights should be duly classified 50 that
| from the large seaeoast light to the small harbor
light the buildings, lighting apparatus, and accesso-
ries, might be the proper scale; the distinctive
Icharucter for the lights adopted which experience
has shown most effective, as fixed, revolving, fixed
lights with flashes, successions Of bright light and
ecpses at regular intervals, and lights Of particular
colors that when ready for illumination, the light.
ing apparatus may be properly kept and attended
to- under effective inspection.
IL is not possible to leave such things these tc
local information, derived at second hand, or to
chances, without paying dearly in the end Voc the
want Of system. ..... ....... ... ~.
j In all these points il appears that other countries
| have advanced rapidly and ii becomes us to SEE
what improvements, introduced elsewhere, art
adapted to our use. and to ascertain how our gene
raj system may be modified. aaasHs.. .. .
i A comparison of the lighting apparatus in use
with US, and of the improved apparatus Of France
shows that in this essential our progress has moi
been as great as might have been deaired. n
4 The reports Of the inspecting officers detailed
| from the navy to examine the lights coas
showed their absolute defects; the present repor
shows their, Deficiencies relative TO those of otho
countries. The trial made of one Of the Frencl
lights, at the entrance TO the New York harbor, a
| Sandy Hook, has been very successful but the use
this apparatus has not been extended. A light
house need be seen from particular parts of the ho
/ rizon only; and the lamps used throw Oft the
lights almost equally all sides, the directions
portions of the rays must be changed. This may
be done by reflection from opake substances, al
from metallic mirrors; or by bending refraction
by transparent bodies, as by glass prsms lenses
| Much more light is lost by the use of the mos
| highly polished surfaces, refectors, than by
| passing through transparent bodies; and hence
! lenses are more useful and economical for light
| house purposes than mirrors. Tse refracting OF
lens apparatus, invented in France by Augus,ir
Fresnel, has been generally applied under the di
rection of his brother, Leonor Fresnel, the present
accomplished secretary of the board of light
| houses. .UrHga 1H. - 'i W fst
I In this apparatus, lenses of glass are used to
| throw the light of powerful lamps in the required
| directions upon the horizons, and the part which
j would otherwise escape upwards is reflected tc
L the horizon by glass prisms, SO placed that thu
rays fall upon the back second surfaces Of the
prisms, at angles at which they entirely reflect
ed The lenses are built up Of separate pieces
of glass, thereby saving the weight and cost o
large masses of material, besides diminishing th,
thickness, and thus preventing the loss Of light b,
absorption and permitting the figure Of the surface
to be adjusted to bring the rays accurately to
focus. IL the lens apparatus be made TO revolve
the navigator will see brilliant flashes OF light grad
ualy growing dim, and succeeded byJshort inter
walls Of comparative darkness; and if second set o
lenses, suitably arranged reyolve about the first
i which remains fixed general illumination will b,
varied by brilliant flashes: these may be white o
colored and thus the appearances of lights may be So
i varied as TO make them distinctive. single lag
lamp, supplied with oil by mechanism, Gas in French
Gght-hopses or by hydrosatic pressure, Gas in SOM
Of The English ones,) is used with tae lens system
I and produces great economy in tho consumption o
oil necessary to supply given quantity of light
II The dimensions of the apparatus are easily varie'
to suit the different quantities Of light required, iron
the small harbor light to the large seacoast light II
the French system, the lights are divided into fou