IMPROVEMENTS IN SHIP AND OTHER LAMPS OR LANTERNS
Year: 1879

page_text: LETTERS PATENT to Albert Marcius Silber, of Wood Street, in the City of
London, for the Invention of "IMPROVEMENTS IN SHIP AND OTHER LAMPS OR
LANTERNS."
Sealed the 25th July 1879, and dated the 7th February 1879.
PROVISIONAL SPECIFICATION left by the said Albert Marcius Silber at the
Office of the Commissioners of Patents on the 7th February 1879.
ALBERT MARCIUS SILBER, of Wood Street, in the City of London.
MENTS IN SHIP AND OTHER LAMPS OR LANTERNS."
"IMPROVE-
In lamps or lanterns such as are employed on ship board and in exposed situations
generally, the external glass is frequently fractured either by reason of the unequal
expansion of the glass and of the metallic framing in which it is secured, and also
in consequence of sudden cooling of the heated glass by the dash of rain or spray,
or by a current of cold air directed upon it. The danger of fracture from these and
other causes is much increased where bent shaped glasses of unequal thickness are
employed, or where the glass itself is made of the material known as plate glass.
In consequence of this risk it is almost impossible to obtain from such lamps or
lanterns the amount of light that is in many cases desirable, the flame being neces-
sarily restricted in order to avoid excessive heating of the glass or its framing. My
Invention relates to means of avoiding the danger of fracture of the glasses in such.
cases, thereby permitting the use of larger and more luminous flames than can be
now safely employed. In order to explain the nature of the means which I employ
for this purpose I will take the case of a ship lamp which is surrounded to the
extent of more than half its circumference by a glass of partly cylindrical form
thickened in the middle of its length, so as to present a lenticular section and to act
as a lens condensing the rays of the light, and diverting them outwards nearly in
one horizontal plane. This glass is peculiarly liable to fracture not only on account
of the great inequality in its thickness but also because it must be tightly secured
to the metal of the lautern in order to prevent access of currents of air or of spray
to the interior. According to my. Invention I fix this glass in a separate framing of
thin metal attached at its edge, and I provide this framing with loops, one at each
side, and secure it to the body of the lantern by pins passed through these loops,
this mode of fixing giving freedom for expansion and contraction of the glass and of
the lantern independently of each other, and thereby relieving the former of all
Prins G71

page_text: strains due to this cause. I make the glass and its frame of a little less depth than
the space in front of the lantern where it is placed, and I rest it on three or more
studs, so that there is passage for air or water underneath the glass, and also above
it from the outside inwards or from the inside outwards. Within the glass I fix to
the lantern another glass of the form of more than half a cylinder, so as to enclose
the frame airtight-between it and the back of the lantern, and I make this glass
thin and well annealed, taking care to have its thickness as nearly as possible
¯uniform-in all parts. This inner glass becomes highly heated by the flame, but in
consequence of its being of uniform small thickness it is not liable to suffer from
strains of expansion.and.contraction,.nor-from-sudden.changes.of_temperature.__In_
the semi-annular space between the inner thin glass and the outer lenticular glass
there is a body of air which owing to its non-conducting property and its freedom
to circulate and become changed, prevents the outer glass from becoming heated so
much as to endanger its fracture. If water or spray should dash against the outer
glass it may find its way into the semi annular space within it, but cannot get into
the flame chamber, and there is freedom for it to flow out again by the passage
under the glass frame. A like construction, with suitable modifications of the forms
of the parts, applies to lamps other than those of the kind employed at sea.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Albert Marcius Silber in the Great Seal Patent Office on the 5th
August 1879.
ALBERT MARCIUS SILBER, of Wood Street, in the City of London.
MENTS IN SHIP AND OTHER LAMPS OR LANTERNS."
"IMPROVE-
In lamps or lanterns such as are employed on shipboard and in exposed situations
generally the external glass is frequently fractured either by reason of the unequal
expansion of the glass and of the metallic framing in which it is secured, and also
in consequence of sudden cooling of the heated glass by the dash of rain or spray,
or by a current of cold air directed upon it. The danger of fracture from these and
other causes is much increased where lens shaped glasses of unequal thickness are
employed, or where the glass itself is made of the material known as plate glass.
In consequence of this risk it is almost impossible to obtain from such lamps or
lanterns the amount of light that is in many cases desirable, the flame being neces-
sarily restricted in order to avoid excessive heating of the glass or its framing. My
Invention relates to means of avoiding the danger of fracture of the glasses in such
cases, thereby permitting the use of larger and more luminous flames than can now
be safely employed. In order to explain the nature of the means which I employ
for this purpose I will take the case of a ship lamp which is surrounded to the
extent of more than half its circumference by a glass of partly cylindrical form
thickened in the middle of its length so as to present a lenticular section and to act
as a lens, condensing the rays of the light and directing them outwards nearly in one
horizontal plane. This glass is peculiarly liable to fracture not only on account of
the great inequality in its thickness, but also because it must be tightly secured to
the metal of the lantern in order to prevent access of currents of air or of spray to
the interior. According to my Invention I fix this glass in a separate framing of
thin metal attached at its edge, and I provide this framing with loops, one at each
side, and secure it to the body of the lantern by pins passed through these loops,
this mode of fixing giving freedom for expansion and contraction of the glass and
of the lantern independently of each other, and thereby relieving the former of all
strains due to this cause. I make the glass and its frame of a little less depth than
the space in front of the lantern where it is placed, and I rest it on three or more
studs, so that there is passage for air or water underneath the glass, and also above
it from the outside inwards or from the inside outwards. Within the glass I fix to
the lantern another glass of the form of more than half a cylinder, so as to enclose
the flame air-tight between it and the back of the lantern, and I make this glass
thin and well annealed, taking care to have its thickness as nearly as possiblo
uniform in all parts. This inner glass becomes highly heated by the flame, but in
consequence of its being of uniform small thickness it is not liable to suffer from
strains of expansion and contraction, nor from sudden changes of temperature. In
the semi-annular space between the inner thin glass and the outer lenticular glass
there is a body of air which, owing to its non-conducting property and its freedom
to circulate and become changed, prevents the outer glass from becoming heated so
much as to endanger its fracture. If water or spray should dash against the outer
glass it may find its way into the semiannular space within it, but cannot get into
the flame chamber, and there is freedom for it to flow out again by the passage
under the glass frame. A like construction, with suitable modifications of the forms
of the parts, applies to lamps other than those of the kind employed at sea.

page_text: secured to the lantern body by its edges, fitting in grooves as shewn at a, a, so as
to enclose completely the front of the lamp. B is the exterior lens glass, which is
held by its edges in a light metal frame b, b. The frame has on each side an eye C,
and there are corresponding eyes D, D, on the lantern body, through which and the
eyes C pins d, d, are passed to hold-the-glass-B-in its place with sufficient slack-
ness to allow for expansion and contraction without straining. The glass B and its
frame rest at their lower_edge on three studs or fillets E. It will be seen that
between the glasses A and B there is a semi-annular space to which there is free
passage above and below the outer glass, as also on either side thereof-between the
frame-b-band-the-lantern-body, so that air can freely circulate between the glasses,
keeping the outer glass cool, and if water or spray should find its way into-the-
space between the glasses it can issue freely by the space below the outer glass.
Although I have shewn in the accompanying Drawings a form and arrangement
of glasses more particularly suited to a ship lamp, it may be readily understood that
similar arrangements are applicable generally to lamps and lanterns for use in
exposed situations.
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I would have it understood that I make no general claim to the
use in lamps or lanterns of double glasses with an air space between them, but I
claim in respect of ship and other lamps and lanterns for use in exposed situations-
The combination of a uniformly thin well annealed inner glass secured to the
body of the lamp or lantern with an outer glass (which may be lenticular) secured
in a separate light frame loosely held to and supported on the body of the lamp or
lantern, so as to give free air passage above and below and at the sides thereof, and
between it and the inner glass, substantially as and for the purposes herein set
forth.
In witness whereof; I, the said Albert Marcius Silber, have hereunto set my
hand and seal, this Thirty first day of July, in the year of our Lord One
thousand eight hundred and seventy-nine.
A. M. SILBER. (L.S.)