A METHOD OF BLEACHING PAPER IN THE WATER LEAF OR SHEET, AND SIZING IT WITHOUT DRYING, WHEREBY THE MANUFACTURE OF IT WILL BE IMPROVED BY SHORTNING ITS PROCESS, LESSENING ITS EXPENCE, AND CONSIDERABLY INCREASING ITS VALUE
Year: 1795

page_text: CARPENTER'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ELIAS
CARPENTER, of the Neckinger, in the Parish of Saint Mary Magdalen,
Bermondsey, in the County of Surry, Gentleman, send greeting.
WHEREAS His present most Excellent Majesty King George the Third,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Nineteenth day of November, in the thirty-sixth year of
His reign, did give and grant unto me, the said Elias Carpenter, my executors,
administrators, and assigns, His especial licence, full power, sole priviledge and
authority, that I, the said Elias Carpenter, my executors, administrators, and
assigns, during the term of fourteen years therein expressed, should and
lawfully might make, use, exercise, and vend, within that part of His said
Majesty's Kingdom of Great Britain called England, His Dominion of
Wales, and Town of Berwick-upon-Tweed, my Invention of "A METHOD OF
BLEACHING PAPER IN THE WATER LEAF OR SHEET, AND SIZING IT WITHOUT
DRYING, WHEREBY THE MANUFACTURE OF IT WILL BE IMPROVED BY SHORTNING
ITS PROCESS, LESSENING ITS EXPENCE, AND CONSIDERABLY INCREASING ITS VALUE;"
in which said Letters Patent there is contained a proviso obliging me, the
said Elias Carpenter, by an instrument under my hand and seal, to cause
a particular description of the nature of my said Invention, and the manner
in which the same' is to be performed, to be inrolled in His Majesty's
High Court of Chancery within one calendar month after the date of the
said Letters Patent, as by the said recited Letters Patent, relation being
thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Elias Carpenter, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is herein-after particularly
described and ascertained (that is to say) :-

page_text: I provide a stout deal box or case, which must be perfectly closed, capablo
of confining water or steam. The cover on the top I make to let into a
groove, the dimensions of which must be regulated by the size of the paper
intended to be bleached in it. One I have made for foolscap paper is three
fect four inches square, and threo fect nine inches deep, with a hole cut in one
side near the top to receive the neck of a retort. In this case I put a false
bottom of deal, bored full of holes, which said bottom, including the feet on
which it stands, takes up a space of about five inches. I have also four deal
frames, made to fit into the said box or case, with two cross bars in eaclı, distant
about fifteen inches from each end, leaving a space in the centre of about four
or five inches. These frames have feet, which make their height about ten
inches. The first of these frames stands on the false bottom, the second on
the first, the third on the second, and the fourth on the third. I then put
into the said box or case, under the falso bottom, a proportion of a certain
liquid, which I shall hereafter describe, the use of which liquid is for the
preservation of the health of the operator. In my frames I have a groove cut
in the inside of each end, and another facing each end in the cross bars.
These grooves receive the end of the laths on which the paper hangs. Much
difficulty arose in finding a contrivance for hanging the paper on. Lines, on
account of their being so close, were particularly inconvenient and tedious, and
those which would be moderate in price gave a stain to the paper. Wood
was subject to the same complaint, and being cut so thin as was necessary,
twisted and warped in all forms; and all metal would rust or corrode in the
operation. Nothing, therefore, appeared so convenient and cheap as glass.
I procured from some glaziers the cuttings of sash squares, in large quantities
of strips from to of an inch broad, and about fifteen inches long. Thus
provided, I took my paper, when pressed in the packs in its wet state, and
laying one of the strips of glass in the middle of the pack, I turned about four
sheets over on it, and placed it edgoways in a groove of one of the frames, then
a second the same way, placing it quite close to the first. Thus I proceeded till
the frame was filled. In like manner I proceeded with the remaining frames,
placing them in the box or case, as before described, making it in the whole
to contain about five reams, the cover of which I place on, aud either close it
with pipeclay or strips of paper pasted on, which latter I prefer as the most
cleanly. I then lute the neck of a glass retort in the whole of the box or case
before mentioned, containing manganese, sea salt, and vitriolic acid, the pro-
portions of which I have frequently varied without discovering any very great
dillerence in its effects, but have generally found equal quantities of manganese
and sea salt, and about of their weight of the vitriolic acid have answered

page_text: best. The manganese and salt must be well mixed together, and put into the
retort; then vitriolic acid must be mixed with an equal quantity of water
impregnated with the fumes of burning sulpher, and put into the other ingre
dients. These mixtures, after standing a short time, require a moderate heat,
which I have, from repeated experiments, found most conveniently.communi-
cated by boiling water. The paper, after having been exposed about eight or
ten hours to the vapour or steam arising from this preparation, will be found
sufficiently whitened, and may be taken from the box or case, and sized with
the following size (that is to say):-Take one hundred weight of pieces of
skins of which size is usually made, and after boiling it to a due consistanco
and straining it, mix with it the following ingredients; (viz',) fourteen
pounds weight of allum, seven pounds of calcined vitriol, and one pound of
gum arabic. This quantity will make size enough for about fifty reams of
foolscap paper. Then press it, and finish in the usual way. This process will
answer extreemly well for a ragg that is devoid of sheaves, and wants only a
brightness of color; but where the rag is of a course bad quality, abounding
with sheaves, it will require the following previous preparation (viz'):-I pre-
pare a lixivium from equal quantities of pearlash and quick lime, fresh from
the kiln, the proportion of about four pounds to each hundred weight of the
article. I pour on water by degrees until the lime is slacked, and mix them
well together, and pour on a large quantity of water, stirring it well several.
times, after which I suffer it to stand till the solution is clear, which I draw
off, adding more water to the residuum till all the salts of the ashes are entirely
dissolved; then draw off the clear and mix with the former, and if not suffi-
cient for the purpose, I add more water to the sollution. With this lixivium I.
either macerate my rag or boil it, as its state and condition may require, the
first of which I prefer as the most cleanly as well as the most economical, but
the latter is the most expeditious and effectual; and when working a close-
wrought rag, made of a hard-twisted thread, and abounding with sheavs, it will
be found necessary to pass it through a washing engine, to open it to give the
lixivium and bleaching principal free access to its internal parts. After it
hath been thus macerated or boiled until the sheaves are extirpated, which will
take a longer or shorter time according to the quality and texture of the rag,
it is then either to be pressed or stand in some convenient receptacle to drain
away the superfluous water, then put into the box or case prepared for bleach-
ing the paper, or any other box, chest, or case, made of wood, of any shape or
dimensions, only observing its perfectly tight. What I have used frequently
for this purpose hath been cases three feet square, and about two feet three
inches deep. The noxious vapour which issues from the bleaching cases.

page_text: immediately on their being opened having made several of the people employed
theroin extremely ill, and having experienced the pernicious effects of it severely
myself, I turned my attention to a preventative; and, considering the attrac-
tions of all alkalys with acids, I discovered, after trying various means, that
the lixivium, which we have always at hand, answered the purpose fully.
When I have put it in too strong, or in too great a quantity, its effects have
been curious. In several of those trials, after putting in my lixivium of
various strengths and quantitys, laying on my false bottom, and throwing in the
article thereon, to the amount of at least one hundred weight and a quarter in
ench case, I have found on opening, after standing the usual time of eight or
ten hours, the case which had the weakest portion of the lixivium well
done throughout; where it was a little stronger, one small spot in the
centre, the color untouched, and where it was strongest one large globular
form in the middle, of about eighteen inches diameter, as full of color as when
put in, white all round, top, bottom, and sides particularly; the bottom was
purely white; this I attributed to the powerful attraction of the lixivium,
drawing the gaz down at the sides and corners, whero it would find an
easier passage than in the centro, where it lay in a more solid body. One
gallon of the second running of the lixivium will be generally found a proper
quantity for every hundred weight to draw the bleaching power into the pulp,
and render the process safe and pleasant to the operator. It may be supposed
much of the gaz must be wasted in the lixivium; if put in injudicially it will,
but if in a proper quantity the same charge will bleach much more effectually
than without, it being so votalile that it's difficult to confine it. I have seen the
finer and more subtile parts penetrate through the neck of a stone retort of
considerable thickness, which is soon rendered porous by repeated use; and,
as soon as the case was opened, great quantities would fly off, and if the people
employed did not fly from it for a time, they would experience a trembling of
the limbs, sick headach, painful sensation at the stomach and throat, and a
wheesing cough, as if afflicted with a violent asthma, all of which is removed
by the application of the lixivium. As the gaz decomposes all these sub-
stances found in the pores of wood, to the destruction of the wood and
continual decrease of the bleaching power, it will be necessary to line the case
with some kind of cement that will repel it. I have lined my box or caso.
with a thick coat of white paint, which hath answered tolerably well. When
I have thus prepared my box or case with the lixivium and false bottom, I fill
it with the article to bleach. Having closed the cover, I fix the retort with
the chymical mixtures heretofore mentioned. The precise charge to each of
these retorts cannot be allixed, but must be regulated by the article to be

page_text: bleached, which the judgment and ingenuity. of the operator must determine;
for instance, that charge which might with safety be employed on a strong
course rag would injure the texture of a fine or tender one; and that charge
alone which would be sufficient for a fine rag would be ineffectual for a very
course one. A few careful experiments will furnish a diligent person with
more instructions and knowledge on these particulars than all that can be
wrote. I have, however, generally found that less than two pounds weight
of vitriolic acid to each hundred weight of rag or pulp hath been insufficient
for the finest, and that more than five pounds weight was mischevious to the
coursest, having a tendency to take out strength as well as color. The heat
communicated to these retorts is by boiling water, as before mentioned, being
neither accompanied with the dirt, the expence or labor of sand heats, and
much more uniform in its effects. Many circumstances may happen to make
separate cases and fire produce different shades; therefore, instead of many
cases I intend having only one, equal in dimensions to all I propose bleaching
at a time, with retorts in proportion, with a trough of some convenient
substance to hold the body of the retorts in boiling water, with a cover to
confine in the steam, by which means the heat will be retained, and the cold
air kept from checking the ascent of the gaz when it becomes weak; one of
about twelve feet long, three feet deep, and twenty-eight inches wide, with
about four retorts, would bleach from six to eight hundred weight at a time.
After the article hath been exposed to the action of the gaz for eight or ten
hours it may be taken out of the cases, and if entirely freed from sheaves, it
may be made into paper; but if any sheaves remain it must be again sub-
mitted to a second maceration or boiling, and made into paper, then finished,
from the packs in the water leaf or sheet, as before particularized.
In witness whereof, I, the said Elias Carpenter, have hereunto set my
hand and seal, this Seventeenth day of December, in the thirty-sixth year
of the reign of our Sovereign Lord George the Third, by the Grace
of God of Great Britain, France, and Ireland King, Defender of the
Faith, and so forth, and in the year of our Lord One thousand seven
hundred and ninety-five.

page_text: AND BE IT REMEMBERED, that on the Seventeenth day of December,
in the year of our Lord One thousand seven hundred and ninety-five, the
aforesaid Elias Carpenter came before our said Lord the King in His
Chancery, and acknowledged the Specification aforesaid, and all and every
thing therein contained and specified, in form above written. And also the
Specification aforesaid was stamped according to the tenor of the Statutes
made for that purpose.
Inrolled the Seventeenth day of December, in the year of our Lord One
thousand seven hundred and ninety-five.