AN IMPROVED PROCESS OF MANUFACTURING CHIMNEYS FOR THE LAMPS OF LIGHTHOUSES
Year: 1873

page_text: LETTERS PATENT to Henry Defries, of the Firm of Jonas Defries and
Sons, of 147, Houndsditch, in the County of Middlesex, for the In-
vention of "AN IMPROVED PROCESS OF MANUFACTURING CHIMNEYS FOR THE
LAMPS OF LIGHTHOUSES."-A communication from abroad by Messrs.
PROVISIONAL SPECIFICATION left by the said Henry Defries at the
Office of the Commissioners of Patents, with his Petition, on the
23rd December 1873.
I, HENRY DEFRIES, of the Firm of Jonas Defries and Sons, of 147,
Houndsditch, in the County of Middlesex, do hereby declare the nature
of the said Invention for "AN IMPROVED PROCESS OF MANUFACTURING CHIMNEYS
FOR THE LAMPS OF LIGHTHOUSES," a communication to me from abroad
by Messrs. O. Schulzer and Co., of Rauscha, Silesia, Prussia, to be as
follows

page_text: to secure the perfect accuracy of form required for the chimneys of
lighthouse lamps. Attempts have also been made to obtain these
chimneys by moulding, but hitherto unsuccessfully from the want of
any means of preventing the formation of a seam and defective surface
upon the chimney. This seam or these marks, although of compara-
tively slight importance in ordinary glass chimneys, becomes a serious
defect in those of large size used in the lamps of lighthouses.
The object of this Invention is to remove this defect, and this object
is attained by the following process:-The workman who takes the
metal from the furnace immediately begins to blow it, and while this
blowing is going on another workman closes a mould around it, the first
workman keeping the glass always turning in the mould until the
chimney is properly made and cool. This continuous turning of the
glass within the mould while in a heated state prevents the formation of
any seam, and the chimney when removed from the mould is quite free
from the mould marks found upon chimneys made in the ordinary
way.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Defries in the Great Seal Patent Office
on the 22nd June 1874.
· TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DEFRIES, of the Firm of Jonas Defries and Sons, of 147, Houndsditch,
in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of December, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry Defries, Her special
licence that I, the said Henry Defries, my executors, administrators,
and assigns, or such others as I, the said Henry Defries, my exccutors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the

page_text: Channel Islands, and Isle of Man, an Invention for "AN IMPROVED PROCESS
OF MANUFACTURING CHIMNEYS FOR THE LAMPS OF LIGHTHOUSES," a communi-
cation to me from abroad by Messrs. O. Schulzer and Co., of Rauscha,
Silesia, Prussia, upon the condition (amongst others) that I, the said
Henry Defries, my executors or administrators, by an instrument in
writing under my, their, or one of their hands and seals, should par
ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Defries, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement :—
The large glass chimneys used in the lamps of lighthouses are usually
blown, but by this method of manufacture it has been found impossible
to secure the perfect accuracy of form required for the chimneys of
lighthouse lamps. Attempts have also been made to obtain these
chimneys by moulding, but hitherto unsuccessfully from the want of
means of preventing the formation of a scam and defective surface upon
the chimney. This seam or these marks, although of comparatively
slight importance in ordinary glass chimneys, becomes a serious defect in
those of large size used in the lamps of lighthouses.
The object of this Invention is to remove this defect, and this object
is attained by the following process :-)
-The workman who takes the
metal from the furnace immediately begins to blow it, and while this
blowing.is going on another workman closes a mould around it, the first
workman keeping the glass always turning in the mould until the
chimney is properly made and cool. This continuous turning of the
glass within the mould while in a heated state prevents the formation of
any scam, and the chimney when removed from the mould is quite free
from the mould marks found upon chimneys made in the ordinary
way.

page_text: part recited Letters Patent, the use of chimneys for the lamps of light-
houses when made by the process herein-before specified.
.
In witness whereof, I, the said Henry Defries, have hereunto
set my hand and seal, this Twenty-second day of June, in
the year of our Lord One thousand cight hundred and seventy- {
four.