AN IMPROVED CORDAGE;
Year: 1825

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CATHCART
DEMPSTER, of Lawrence Pountney Hill, in the City of London, send greeting.
WHEREAS I, the said Cathcart Dempster, did, by my Petition, humbly
represent to His present Majesty King George the Fourth, that I had
invented "AN IMPROVED CORDAGE;" that in regard I was the first and true
Inventor thereof, and that the same had never been practised by any other
person or persons whomsoever, to my knowledge or belief, I humbly prayed
His said Majesty that He would be graciously pleased to grant unto me, my
executors, administrators, and assigns, His Royal Letters Patent under His
Great Seal of His United Kingdom, for the sole use, benefit and advantage
of my said Invention, within England, Wales, and the Town of Berwick-
upon-Tweed, and also in His Colonies and Plantations abroad, for the term of
fourteen years, pursuant to the Statute in that case made and provided; His
said Majesty, being willing to give encouragement to all arts and inventions
that may be for the public good, was graciously pleased to condescend to my
request, and therefore, by Royal Letters Patent, bearing date at Westminster,
the Fifteenth day of September, in the sixth year of His reign, of His
especial grace, certain knowledge, and mere motion, did give and grant unto
me, the said Cathcart Dempster, my executors, administrators, and assigns,
and every of us, by myself or themselves, or by mine or our deputy or

page_text: deputies, servants or agents, or such others as I, the said Cathcart Dempster,
my executors, administrators, or assigns, at any time should 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 my said Invention, within that part of His said Majesty's said
United Kingdom of Great Britain called England, His Dominion of Wales,
and Town of Berwick-upon-Tweed, and also in His Colonies and Plantations
abroad, in such manner as to me, the said Cathcart Dempster, my executors,
administrators, and assigns, or any of us, should in our descretion seem meet;
and that I, the said Cathcart Dempster, my executors, administrators, and
assigns, should and might lawfully enjoy the whole profit, benefit, com-
modity, 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,
privileges, and advantages therein-before granted or mentioned to be granted
unto me, the Cathcart Dempster, my executors, administrators, and assigns,
for and during and unto the full end and term of fourteen years from the date
of the said Presents next immediately ensuing, and fully to be complete
and ended, according to the Statute in such cases made and provided; in which
said Letters Patent is contained a proviso that if I, the said Cathcart
Dempster, should not particularly describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, by an in-
strument in writing under my hand and seal, and cause the same to be
inrolled in His said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said Letters Patent, that
then the said Letters Patent, and all liberties and advantages whatsoever
thereby granted, should utterly cease, determine, and become void, anything
therein-before contained to the contrary thereof in anywise notwithstanding,
as in and by the said Letters Patent, relation being thereto had, may more
fully and at large appear.
NOW KNOW YE, that I, the said Cathcart Dempster, in compliance
with the said proviso, do hereby describe and ascertain the nature of my said
Invention, and the method of making and manufacturing my said improved
cordage, to be as follows:-
I take such a quantity of raw hemp or other vegetable fibre as I intend to
make into cordage, and have such hemp or fibre properly dressed or hackled
and spun into rope yarns by the most approved methods in usual practice; I
then connect together a number of the yarns (the number varying according
to their gith, size, or thickness) into what is technically called by the rope

page_text: makers a hawl, and the operation is performed in the manner long known and
used. In proportion to every ton weight, or two thousand two hundred and
forty pounds avoirdupois, of such cordage yarns, I take ten pounds avoirdupois
of corrosive sublimate or bichloride of mercury; thirty pounds of avourdupois
of acetate of sugar of lead, and fifty pounds avoidupois of alum. I then, in
a wooden or other proper vessel, dissolve these ingredients in such a quantity
of soft water as will be sufficient to saturate the yarns. This quantity will
necessarily vary according to the dryness of the material to which it is to be
applied, but from two hundred and fifty to three hundred gallons will to be
found enough. The water must be raised to a temperature sufficiently warm
to effect a complete dissolution of the corrosive sublimate acetate of lead and
alum. A heat of one hundred and fifty to two hundred degrees of Fahrenheit's
themometer will answer the purpose, according to the temperature of the
weather. A little practice will serve to regulate the necessary quantity of
water and the required degree of heat. A little excess either in the quantity
of the water or its temperature is of no very material consequence. I then
use a water-tight wooden or other proper trough or vessel, or troughs or
vessels, of sufficient dimensions, proportioned to the quantity of cordage yarns
I intend to impregnate with the solution before mentioned, and in such trough
or troughs, vessel or vessels, I lay the cordage yarns, connected together in a
hawle as before described, side by side, and in a single stratum horizontally. I
then, by means of a watering pot or other proper implement or perforated
vessel, gradually impregnate or saturate the stratum of cordage yarns so laid
down with a portion of the before-mentioned solution, which solution may be
applied and used either in a warm or cold state. I then take a further
quantity of dry cordage yarns, connected as aforesaid, and place the same also in
a single stratum over those that have been saturated; and then I, as before,
pour over the last-mentioned cordage yarns a quantity of the same solution,
sufficient fully to saturate and impregnate the said yarns, and proceed, stratum
super stratum, to lay down and impregnate in a similar manner the entire
portion of cordage yarns required at the time. The solution used for im-
pregnating the cordage yarns every time any portion thereof is withdrawn from
the containing vessel must be agitated and well stirred up. Although, to save
labour, I, as above mentioned, dissolve the different ingredients in one vessel
together, it will certainly be equally, if not more efficacious, if the solution be
performed in two separate vessels; that is to say, the corrosive sublimate and
acetate of lead, after solution in a separate vessel, may be first applied to each
single stratum of cordage yarns, and immediately followed by that of alum
dissolved in the other separate vessel.
Either method will answer extremely

page_text: well; but I should prefer the mode of separate solution, as by the latter process
the sulphate of lead, which is precipitated by the action of the alum. from the
acetate of lead, will have the chance of being more intimately incorporated with
the fibre of the hemp or other vegetable substance employed. I allow the
rope yarns to lie in the solution or solutions with which they have been
impregnated for the spaco.of.ten.oritwelve,hours.; I then withdraw them, and
press or wring out a portion of the moisture they contain, so that they may be
dried more easily, either by atmospheric exposure or by artificial heat. When
the yarns are sufficiently dry they are to be made into rope or cordage in the
usual way, and; according to the dimensions required, without the application
of tar, pitch, rosin, or any substance. of the same nature. Although I prefer
applying the solution or solutions above mentioned to hemp or other vegetable
fibre after the same has, been spun into yarns, yet an equally beneficial effect
would be produced if they be applied to hemp or other vegetable fibres in 'their
loose or undressed state. But in this way of proceeding great caution will be
required to prevent the fibres, becoming matted or entangled together, and
thereby rendered more difficult to be hackled or dressed for spinning. And
although I consider the mode or method of saturation before described to be
preferable, still the same or partial effects might be produced by immersion of
the cordage yarns or the hemp or vegetable fibre in the solution or solutions
before mentioned.
The advantages which are to be derived from the manufacture of cordage in
the manner above described.are;
:
First, the exclusion of the use of tar, pitch, 'rosin, and other similar sub-
stances in the making of ropes.
Secondly, the preservation of the hemp or, vegetable fibro used, by the
application of the antiseptic ingredients above specified, by which process ithe
durability-and-strength of the cordage-are-insured-to-a-greater-extent-than-is
obtained by the mode of manufacturing it at present in practice.
Thirdly, the pliability of the cordage produced by the above method is
much greater than that of cordage made in the usual way, and the capabilities
of working and coiling it for nautical and other purposes to which cordage
is applicable are greatly increased.
Fourthly, a great diminution in weight, and a lessening of the girth or size
required by the present. system of rope making, according to the purposes
for which it is to be applied.
Although I consider the substances above named, and the quantities to be
used as above specified, as most-fit and proper for the intended purposes, I am
well aware that effects partially similar may be produced by the application-of

page_text: a larger or smaller quantity of the several ingredients to the same weight
of yarns or hemp or other vegetable fibre, and by the use of other chemical
compounds possessing antiseptic properties.
In witness whereof, I have here set my hand and seal, the Fourteenth
day of March, in the year of our Lord One thousand eight hundred
and twenty-six