NEW INVENTED METHOD OF MAKING ALL KINDS OF GLASS BY A VERY CONSIDERABLE IMPROVEMENT IN THE CONSTRUCTION OF THE FURNACE, AND THE FLUES CONNECTED WITH IT, WHICH OCCASIONS A GREATER FLOW OF AIR THROUGH THE FURNACE, AND THEREBY PRODUCES SUCH INTENSE HEAT AS TO FUSE THE MATERIALS IN LESS THAN
Year: 1802

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DONALDSON, of the Parish of Saint Mary, Redclift, in the City and County of
Bristol, Glass Manufacturer, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under His Great Seal of Great Britain, bearing date at West-
minster, the Fifth day of March, in the forty-second year of Ilis reign, did
grant unto me, the said John Donaldson, my executors, administrators, and
assigns, His said Majesty's especial licence, full power, sole privilege, and
authority that I, the said John Donaldson, my executors, administrators, and
assigns, and every of them, by myself and themselves, or by mine and their
deputy or deputies, servants or agents, or such others as I, the said John
Donaldson, my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend, any "NEW INVENTED METHOD OF MAKING ALL KINDS OF GLASS BY A VERY
CONSIDERABLE IMPROVEMENT IN THE CONSTRUCTION OF THE FURNACE, AND THE FLUES
CONNECTED WITH IT, WHICH OCCASIONS A GREATER FLOW OF AIR THROUGH THE FURNACE,
AND THEREBY PRODUCES SUCH INTENSE HEAT AS TO FUSE THE MATERIALS IN LESS THAN

page_text: ONE HALF OF THE USUAL TIME, WITH A SAVING OF FULL ONE THIRD PART OF THE COAL
GENERALLY CONSUMED, AND RENDERING THE GLASS OP A BETTER QUALITY," within
that part of His Majesty's United Kingdom of Great Britain and Ireland called
England, His Dominion of Wales, and Town of Berwick-upon-Tweed, in such
manner as to me, the said John Donaldson, my executors, administrators, and
assigns, or any of them, should, in their discretions seem meet, and that I, the
said John Donaldson, my executors, administrators, and assigns, should and law-
fully might have and enjoy the whole profit, benefit, commodity, and advantage
from time to time coming, growing, accruing, and arising by reason of the
said Invention for and during the term of years therein mentioned; to have,
hold, exercise, and enjoy the said licence, powers, priviledges, and advantages
therein-before granted, or mentioned to be granted, unto me, the said John
Donaldson, my executors, administrators, and assigns, for and during and unto
the full end and term of fourteen years from the date thereof next immediately
ensuing, and fully to be compleat and ended, according to the Statute
in that case made and provided; in which said recited Letters Patent is
contained a proviso that if I, the said John Donaldson, should not particularly
describe and ascertain the nature of my said Invention, and in what manner the
same was to be performed, by an instrument in writing under my hand and
seal, and cause the same to be inrolled in His Majesty's High Court of
Chancery within one calendar month next and immediately after the date
thereof, that then the said recited Letters Patent, and all liberties and advan-
tages whatsoever thereby granted, should utterly cease, determine, and become
void, anything therein-before contained to the contrary thereof in anywise' not-
withstanding, as in and by the said recited Letters Patent, reference "being
thereunto had, will more fully and at large appear.
NOW KNOW YE, that I, the said John Donaldson, in compliance with
the said proviso, do hereby declare that my said Invention is described in
manner following (that is to say) :-
After the body of the furnace itself is constructed in the usual förm "and"
dimensions, or of any other form or dimensions that experience háth shewn or
hereafter may shew to be advantageous to the manufacture, (in all or any part
of which construction as aforesaid I claini no exclusive priviledge, except so far
as the same shall or may be united or combined with my improvement herein-
after to be described.) I proceed to inclose the same within another building
well adapted to prevent the external air from having any access to the 'fire,"
except through the ash-pit and grate, and I make the said last-mentioned
building of such a figure and height that the rarefied air which liath passed

page_text: through the fire, and issued forth from the apertures or flues of the furnace
into the said surrounding building, shall occupy the interior space,thereof,, and
produce the same effect upon the draft of air, by which the fire is urged and,
maintained as is produced by the heated air in any other elevated chimney.
(the scientific causes of which are well known and need not be here,explained),
and in order that the workmen may have convenient access to the working.
flues, and that the heat (which during the perfect closure of the surrounding
edifice is extreme) may be moderated for working, I form certain openings in the
said building, which are to be closed in a fit and proper manner by iron doors,
or otherwise, whenever the extreme heat is required, but which are opened by
taking the same down at the time of working, and thereby permit the external
air to enter between the. furnace and the surrounding edifice,.so as to reduce
the draught to the ordinary standard or force. And I do hereby declare that
the figure and dimensions of the said surrounding edifice or building are
susceptible of considerable variation, according to the circumstances of the work
itself, and the judgment of the operator, who must be supposed to possess
sufficient skill to perform a work of this kind in a proper manner; but that
in general I do advise and prefer a conical figure, of considerable elevation, for
the external building, having its orifice or chimney at the top, and its base of
such a diameter as that its internal face may be less than one foot distant from
the nearest projecting part of the curvature of the furnace, and having side
appertures to be closed as aforesaid, made and constructed opposite th working
flues, and that for the safe and perfect construction of which the skill and
precautions usually employed in works of this nature will be fully sufficient
without further instructions.
In witness whereof, I, the said John Donaldson, have hereunto set my
hand and seal, the Nineteenth day of March, in the forty-second year
of the reign of our Sovereign Lord George the Third, by the grace of
God of the United Kingdom of Great Britain and Ireland King,
Defender of the Faith, and in the year of our Lord One thousand eight
hundred and two.
JOHN (L.S.) DONALDSON.
Signed, sealed, and delivered, by the within-
named John Donaldson, in the presence of
WILL HENRY CLAYFIELD.
ISAAC COOKE, Att-at-Law, Bristol.

page_text: AND BE IT REMEMBERED, that on the Twenty-second day of March,
in the year of our Lord 1802, the aforesaid John Donaldson came before our
said Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stampt according to the
tenor of the Statutes made for that purpose.
Inrolled the Twenty-third day of March, in the year of our Lord One
thousand eight hundred and two.

page_text: DONALDSON'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DONALDSON, of the Parish of Saint Mary, Redclift, in the City and County of
Bristol, Glass Manufacturer, send greeting.
WHEREAS His most Excellent Majesty King Georgo the Third, by His
Letters Patent under His Great Seal of Great Britain, bearing date at West-
minster, the Fifth day of March, in the forty-second year of Ilis reign, did
grant unto me, the said John Donaldson, my executors, administrators, and
assigns, His said Majesty's especial licence, full power, sole privilege, and
authority that I, the said John Donaldson, my executors, administrators, and
assigns, and every of them, by myself and themselves, or by mine and their
deputy or deputies, servants or agents, or such others as I, the said John
Donaldson, my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times theroafter during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend, any "NEW INVENTED METHOD OF MAKING ALL KINDS OF GLASS BY A VERY
CONSIDERABLE IMPROVEMENT IN THE CONSTRUCTION OF THE FURNACE, AND THE FLUES
CONNECTED WITH IT, WHICH OCCASIONS A GREATER FLOW OF AIR THROUGH THE FURNACE,
AND THEREBY PRODUCES SUCH INTENSE HEAT AS TO FUSE THE MATERIALS IN LESS THAN

page_text: ONE HALF OF THE USUAL TIME, WITH A SAVING OF FULL ONE THIRD PART OF THE COAL
GENERALLY CONSUMED, AND RENDERING THE GLASS OF A BETTER QUALITY," within
that part of His Majesty's United Kingdom of Great Britain and Ireland calle
England, His Dominion of Wales, and Town of Berwick-upon-Tweed, in suel
manner as to me, the said John Donaldson, my executors, administrators, and
assigns, or any of them, should, in their discretions seem niect, and that I, the
said John Donaldson, my executors, administrators, and assigns, should and law-
fully might have and enjoy the whole profit, benefit, commodity, and advantage
from time to time coming, growing, accruing, and arising by reason of the
said Invention for and during the term of years therein mentioned; to have,
hold, exercise, and enjoy the said licence, powers, priviledges, and advantages
therein-before granted, or mentioned to be granted, unto me, the said John
Donaldson, my executors, administrators, and assigns, for and during and unto
the full end and term of fourteen years from the date thereof next imme.liately
ensuing, and fully to be compleat and ended, according to the Statute
in that case made and provided; in which said recited Letters Patent is
contained a proviso that if I, the said John Donaldson, should not particularly
describe and ascertain the nature of my said Invention, and in what manner the
same was to be performed, by an instrument in writing under my hand an
seal, and cause the same to be inrolled in His Majesty's High Court of
Chancery within one calendar month next and immediately after the date
thereof, that then the said recited Letters Patent, and all liberties and advan-
tages whatsoever thereby granted, should utterly cease, determine, and become
void, anything therein-before contained to the contrary thereof in anywise not-
withstanding, as in and by the said recited Letters Patent, reference being
thereunto had, will more fully and at large appear.
NOW KNOW YE, that I, the said John Donaldson, in compliance with
the said proviso, do hereby declare that my said Invention is described in
manner following (that is to say) :-
:-
After the body of the furnace itself is constructed in the usual form and
dimensions, or of any other form or dimensions that experience hath shewn or
hereafter may shew to be advantageous to the manufacture, (in all or any part
of which construction as aforesaid I claim no exclusive priviledge, except so far
as the same sball or may be united or combined with my improvement l.crein-
after to be described,) I proceed to inclose the same within another building:
well adapted to prevent the external air from having any access to the fire,
except through the ash-pit and grate, and I make the said last-mentioned
building of such a figure and height that the rarefied air which bath assed

page_text: through the fire,' and issued forth from the apertures or flues of the furnace
into the said surrounding building, shall occupy the interior: space thereof, and
produce the same effect upon the draft, of air, by which the fire is urged and.
maintained as is produced by, the heated air in any other. elevated chimney.
(the scientific causes of which are well known and need not bo hero cxplained), ·
and in order that the workmen may have convenient access to the working.
flues, and that the heat (which during the perfect closure of the surrounding
edifice is extreme) may be moderated for working, I form certain openings in the
said building, which are to be closed in a fit and proper manner by iron doors,
or otherwise, whenever the extreme heat is required, but which are opened by
taking the same down at the time of working, and thereby permit the external
air to enter between the furnace::and. the surrounding cdifice,.so as to reduce
the draught to the ordinary standard or force. And I do hereby declare that
the figure and dimensions of the said surrounding edifice or building are
susceptible of considerable variation, according to the circumstances of the work
itself, and the judgment of the operator, who must be supposed to possess
sufficient skill to perform a work of this kind in a proper manner; but that
in general I do advise and prefer a conical figure, of considerable clevation, for
the external building, having its orifice or chimney at the top, and its base of
such a diameter as that its internal face may be less than one foot distant from
the nearest projecting part of the curvature of the furnace, and having side
appertures to be closed as aforesaid, made and constructed opposite th working
flues, and that for the safe and perfect construction of which the skill and
precautions usually employed in works of this nature will be fully sufficient
without further instructions.
In witness whereof, I, the said John Donaldson, have hereunto set my
hand and seal, the Nineteenth day of March, in the forty-second year
of the reign of our Sovereign Lord Georgo the Third, by the grace of
God of the United Kingdom of Great Britain and Ireland King,
Defender of the Faith, and in the year of our Lord One thousand eight
hundred and two

page_text: AND BE IT REMEMBERED, that on the Twenty-second day of March,
in the year of our Lord 1802, the aforesaid John Donaldson came before our
said Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stampt according to the
tenor of the Statutes made for that purpose.
Inrolled the Twenty-third day of March, in the year of our Lord One
thousand eight hundred and two.