- Email: [email protected]
Museum
Dec.,
1952.1
THE
FRAXKLIN
INSTITUTE
541
MUSEUM It is impossible
to say when, in the age of man, guiding lights first came into use to aid
We might with some justification claim that Homer alludes to them (see Pope’s the mariner. translation of The Iliad, XIX : 405-9). Virgil also speaks of a light on Mount Leucas. The first
light of undoubted record was the famous Pharos of Alexandria, built about 285 B.C.
The lighthouse at Corunna, Spain is believed to be the oldest in existence, having been built in the reign of the Emperor Trajan and reconstructed
in 1634.
The Corduan Tower, at the
mouth of the Gironde, in the Bay of Biscay, is probably the most renowned of its kind. Completed in 1611, it stands 197 feet high. The tower itself contains a chapel and numerous apartments,
although the light-keeper lives in a circular structure which serves as a breakwater
at the base. The lighthouse
system of this country
commenced
with its commerce.
There is little
doubt that the colonists recognized the necessity for beacons with which to guide their homereturning shallops to a safe anchorage, and that they took effective means to show the English and Dutch ships which should make their landfall at night the safe way to their harbor.
The
first authentic evidence of this being done at the public charge was in 1673 when it was recorded in the proceedings of the general court of the Province of Massachusetts of Nantasket
Bay that the citizens
(now Hull) had built a beacon on Point Allerton, the most prominent headland
near the entrance to Boston Harbor,
and furnished it with “lier bales of pitch and ocum.”
The first lighthouse was built at the entrance to Boston Harbor, on Little Brewster Island, in 171.5-6. Not until 1789 did the United States authorities accept jurisdiction over the lighthouses on the coast, which at that time were nine in number. In spite of complaints
that the lighthouse service was both inadequate and inefficient very
little was done to improve the service until the middle of the 19th century, and two prominent members
of The Franklin
were largely responsible
Institute,
Professors
for the introduction
Joseph Henry and Alexander of scientific
methods
Dallas Bathe
in illumination
and fog
One of the most significant improvements was the introduction of the Fresnel lens. signals. When this type of lens was first introduced into this country after its general adoption in Europe, the members of The Institute appointed were most enthusiastic
in endorsing the adoption
a committee
to examine its claims.
They
of the lens for lighthouses.
The Museum has several specimens of Fresnel lenses, but much the most impressive is that which was used in the Fire Island Light between
1858 and 1932.
This great lens, or more
correctly group of lenses, stood 166 feet above sea level and cast its beam over nineteen miles of water.
Originally its light was furnished by an oil wick lamp, but this was changed to an
incandescent
oil vapor lamp of 280,000 candle-power.
When the lens, which may be seen on
the Ground Floor of the Museum, wa’s in service, it was operated by a clockwork
mechanism
and an elaborate system of weights which ran down a tube through the center of the structure. These weights required winding every four hours. It is now operated by a tiny electric motor. The whole lens weighs between four and five tons. When it was about to be replaced in 1933, it was still in good condition, but local navigators pointed put that the arrangements
for flashing were not satisfactory.
The beam shone with
full strength for five seconds before sweeping on to leave a fifty-five seconds period of darkness. The duration of the beam was too short to get satisfactory bearings. The result was that the new light was regulated
to have eight cycles a minute, with only momentary
intervals
of
darkness. Visitors occasionally
comment
upon holes and cracks in the thick glass and wonder how
these could have been caused in an isolated location and at such an altitude. A former keeper of the light told us that these were caused by sea gulls, driven before the blasts of heavy gales, colliding with the glass.
1952.1
THE
FRAXKLIN
INSTITUTE
541
MUSEUM It is impossible
to say when, in the age of man, guiding lights first came into use to aid
We might with some justification claim that Homer alludes to them (see Pope’s the mariner. translation of The Iliad, XIX : 405-9). Virgil also speaks of a light on Mount Leucas. The first
light of undoubted record was the famous Pharos of Alexandria, built about 285 B.C.
The lighthouse at Corunna, Spain is believed to be the oldest in existence, having been built in the reign of the Emperor Trajan and reconstructed
in 1634.
The Corduan Tower, at the
mouth of the Gironde, in the Bay of Biscay, is probably the most renowned of its kind. Completed in 1611, it stands 197 feet high. The tower itself contains a chapel and numerous apartments,
although the light-keeper lives in a circular structure which serves as a breakwater
at the base. The lighthouse
system of this country
commenced
with its commerce.
There is little
doubt that the colonists recognized the necessity for beacons with which to guide their homereturning shallops to a safe anchorage, and that they took effective means to show the English and Dutch ships which should make their landfall at night the safe way to their harbor.
The
first authentic evidence of this being done at the public charge was in 1673 when it was recorded in the proceedings of the general court of the Province of Massachusetts of Nantasket
Bay that the citizens
(now Hull) had built a beacon on Point Allerton, the most prominent headland
near the entrance to Boston Harbor,
and furnished it with “lier bales of pitch and ocum.”
The first lighthouse was built at the entrance to Boston Harbor, on Little Brewster Island, in 171.5-6. Not until 1789 did the United States authorities accept jurisdiction over the lighthouses on the coast, which at that time were nine in number. In spite of complaints
that the lighthouse service was both inadequate and inefficient very
little was done to improve the service until the middle of the 19th century, and two prominent members
of The Franklin
were largely responsible
Institute,
Professors
for the introduction
Joseph Henry and Alexander of scientific
methods
Dallas Bathe
in illumination
and fog
One of the most significant improvements was the introduction of the Fresnel lens. signals. When this type of lens was first introduced into this country after its general adoption in Europe, the members of The Institute appointed were most enthusiastic
in endorsing the adoption
a committee
to examine its claims.
They
of the lens for lighthouses.
The Museum has several specimens of Fresnel lenses, but much the most impressive is that which was used in the Fire Island Light between
1858 and 1932.
This great lens, or more
correctly group of lenses, stood 166 feet above sea level and cast its beam over nineteen miles of water.
Originally its light was furnished by an oil wick lamp, but this was changed to an
incandescent
oil vapor lamp of 280,000 candle-power.
When the lens, which may be seen on
the Ground Floor of the Museum, wa’s in service, it was operated by a clockwork
mechanism
and an elaborate system of weights which ran down a tube through the center of the structure. These weights required winding every four hours. It is now operated by a tiny electric motor. The whole lens weighs between four and five tons. When it was about to be replaced in 1933, it was still in good condition, but local navigators pointed put that the arrangements
for flashing were not satisfactory.
The beam shone with
full strength for five seconds before sweeping on to leave a fifty-five seconds period of darkness. The duration of the beam was too short to get satisfactory bearings. The result was that the new light was regulated
to have eight cycles a minute, with only momentary
intervals
of
darkness. Visitors occasionally
comment
upon holes and cracks in the thick glass and wonder how
these could have been caused in an isolated location and at such an altitude. A former keeper of the light told us that these were caused by sea gulls, driven before the blasts of heavy gales, colliding with the glass.