A NEW AND IMPROVED METHOD OR METHODS OF UNITING OR SOLDERING METALLIC SUBSTANCES
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LUKE
HEBERT, late of Camden Town, in the County of Middlesex, Civil Engineer,
but now residing at Birmingham, in the County of Warwick, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirty-first day of May, in the first year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Luke
Hebert, Her especial licence, full power, sole privilege and authority, that
I, the said Luke Hebert, my exors, admors, and assigns, or such others as
I, the said Luke Hebert, my exors, adññors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, the
Invention of "A NEW AND IMPROVED METHOD OR METHODS OF UNITING OR
SOLDERING METALLIC SUBSTANCES," communicated to me by a certain Foreigner
residing abroad; in which said Letters Patent is contained a proviso that I,
the said Luke Hebert, shall cause a particular description of the nature of
the said Invention, and in what manner the same is to be performed, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto. had, will more
fully and at large appear.
7

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Luke Herbert, do hereby declare that the following is a true Specification of
the aforesaid Invention.
Instead of the well-known processes heretofore employed, and now
actually practised in these kingdoms, of uniting or soldering the more fusible
metals, such as lead and its alloys, with tin, antimony, zinc, and bismuth, it is
designed to introduce a new and much more advantageous system of operating
which has lately been discovered in France, and which system consists in
perfectly uniting separate pieces of the aforesaid metals, of whatever form, by
fusion alone of their edges or other parts required to be joined, and without
the employment of any other metal or metallic mixture in addition denominated
"solder." This union is effected by melting simultaneously the adjoining
edges or surfaces to be united by means of very intense and forcible jets of
flame, either tranquil, straight, and very sharp. or fluttering, and scattered at
their ends according to circumstances (denominated by the inventor darts of
flame), in whatever way the said jets or darts are produced, provided they are
rendered capable of being applied as a fire tool in every necessary direction at
.the operator's will, that their action be very intense, at the same time under
perfect control as to the degree of intensity, and capable of being circumscribed
as to the points acted upon, in order that the agglomeration and complete
union of the melted points may take place before the liquifaction extends itself
to the more remote parts. Darts of flame applicable to these purposes may
be produced by a variety of methods, particularly by the combustion of jets of
gas or vapours, either pure or mixed with oxygen or air; but that which is pre-
ferred by me as the cheapest and most convenient is the following:-Burning,
under the pressure of a few inches of water, gaseous mixtures of air and of
hydrogen, either pure or mixed with small quantities of carburetted hydrogen
or carbon oxide, such as is designated "bad coal gas." The production, mix-
ture, and combustion is effected by means of an improved oxy-hydrogen blow
pipe, which I have named the aerhydric blow pipe, as being adapted to be
supplied with atmospheric air and not oxygen. It consists in a combination
of several instruments or parts of instruments, each of which is already known
and has been employed in the arts and sciences for various purposes, but
which as now combined form a new arrangement of apparatus peculiarly
applicable to the various methods of soldering or uniting metals described in
this Specification.
The several necessary parts which constitute this new arrangement are the
following-First, a self-acting and self-regulating gas generator, or a gas
holder, of whatever principle, giving for several hours or days together a

page_text: regular and continuous current of hydrogen, either pure or carburetted,
provided the gases be produced or collected under a pressure equal to eight or
ten inches of water at the least before being expended. Second, a pair of
bellows or an air-forcing machine of any kind that will produce, under a
pressure equal to that of a few inches of water, at the least a regular and
continual current of air, and in sufficient quantity for the combustion of the
aforesaid gases. Third, a treble connecting tube, provided with two stopcocks,
to each of which the current of air and of gas are conducted by rigid or flexible
tubes, to be mixed before being projected into the atmosphere, whilst the third
branch of the treble tube is furnished either with a flexible tube or with joints,
so disposed that the flame jets may be brought from any required distance and
applied in any direction at the operator's will, which result has never been
before obtained in any apparatus for the purposes mentioned. Safety chambers
partly filled with liquid or any other safety apparatus may be employed for the
passage of the currents of air and gas previous to their passing through the
regulating cocks, but no such apparatus is necessary. The forms of aerhydric
blow pipes may of course be extremely varied; but one of the best specimens
of a portable one, as it is constructed for the supply of self-generated hydrogen,
is represented in Sheet A, Figures 1, 2, 3, 4, which are drawn to a scale of
one fifth the real size, lineal measure.
Figure 1 is an external elevation, the lateral door being taken away;
Figure 2, a vertical section, made through the lines indicated at A, B, and
C, D, in the Figures 3 and 4; Figure 3 is a horizontal section made through
the lines E, F, on Figures 1 and 2; and Figure 4 is a plan of the top of
the apparatus when the protecting lid is taken off. Figure 5 represents
on a scale of half the size, lineal measure, that part of the apparatus which
is used for making the air and gas, and for regulating and directing the flame
darts. The letters from a to k have reference to that portion of the apparatus
which is employed for the self-generation of pure hydrogen, and is constructed
on the principle of Gay Lussac's apparatus already in use. The principal
novelty of the machine here represented consists in making the reservoirs,
tubes, &c. of thin sheet lead, united by fusion of the metal without solder;
at a is the upper reservoir, which is to be charged with sixteen pints of
diluted sulphuric acid, of the specific gravity 1.16, through the hole b,
which is provided with a cork stopper, fastened down by a transverse
copper wire.
c is a leaden tube soldered to the upper reservoir. d is
a stopper, by means of which the communication between both reservoirs
can be intercepted. The rod and handle of this stopper are made of iron,
coated with lead, and the lower end of the lower has a casing of cautchouc to

page_text: form an elastic and impervious closing; ate is the lower leaden reservoir
filled with zinc clippings, introduced through the mouth f, which is closed air-
tight by set screws. g is a leaden false bottom, minutely perforated and
supporting the metallic clipping. h is a leaden tube, soldered to the lower
reservoir, dipping into a cavity or well below the general bottom surface. i is
a small caoutchouc tube, by which the two leaden tubes c, h, are united air-
tight externally, but so as to let both reservoirs communicate. j is a leaden
tube, closed by a cork, and through which the saturated acid is discharged.
k, another leaden tube in two parts (united by caoutchouc), which conducts
the hydrogen generated in the lower reservoir into the safety chamber. I is a
a stopcock soldered to the tube k. m, the leaden safety chamber, filled with
water or oil up to the dotted line, and provided with short charging and dis-
charging pipes and cork stoppers. n is a brass screwed socket, upon which
fits the tube x. o is a pair of circular vertical bellows, raised by the levers
P, p', by the agency of the hand, or through the medium of a cord worked at
any required distance, or it may be by a pedal on the lower lever p', and
depressed by the flat weights q (which weigh about 12 lbs.). r is a leaden
air tube, to the end of which fits the tube x. s, a wooden vessel bound with
iron hoops, and in which the whole apparatus is solidly fixed. t, a protecting
lid or cover, by means of which the upper part of the apparatus is shut down
and locked. u, a lateral door, through which the lower reservoir is charged
with the zinc. v, hooks and rings for fixing leather straps to enable a work-
man to carry it on his back. In Figure 5, a shews the small brass pieces
which fit upon m and n (Figure 2). y, caoutchouc tubes, distended and
supported internally with spiral coils of tinned copper wire, and bound exter-
nally with cotton. These elastic tubes are closely tied upon the pieces x, and
may be made of any required length for conducting the streams of air and gas
to the points of action. 2, regulating air and gas stopcocks, upon each of
which one of the ends of the caoutchouc tubes is fixed. 1, treble connecting
tubes, in which the mixture of air and gas is effected. 2, the caoutchouc
tubes (usually about five feet long to the portable instruments), provided with
screwed brass ends, one of which is screwed upon the treble (or three way)
connecting tube. 3, small brass jet tube, straight, or bent into any convenient
figure, one end of which is screwed to 2, and to the other is screwed a per-
forated nozzle 4, through which the gaseous mixture escapes. The orifices of
the nozzles are made of diemensions varying from the two hundredth to the
sixth of an inch in diameter, or even more longitudinal nozzles, having a series
of lateral apertures in a line, may sometimes be employed advantageously.
It is scarcely necessary to observe, that the whole of the apparatus wherein

page_text: the aeriform or fluid matters are disposed should be made and preserved air-
tight, and have leather or caoutchouc washers to the joints. It will also be
obvious, that the reservoirs, and consequently the power of the gas generator,
may be considerably increased without altering the dimensions of the other
parts. The largest portable aerhydric blow pipe hitherto made by the Inventor
contained about twenty-four quarts of diluted acid. When the apparatus is
once charged with the metal and diluted acid, and the air which previously
filled the vessels is discharged, the opening of the intermediate stopper and of
the gas stopcock is sufficient to set it into action at any time, and to produce
for many hours together a continual stream of gas, which may be limited and
regulated according to the requirements of the operator. It may be found
convenient in some circumstances to substitute for the generative portion of
this apparatus a strong gas holder, containing from ten to thirty cubic feet of
combustible gas, compressed to from ten to thirty atmospheres by the usual.
process, and furnished with an ordinary regulator to govern its discharge, in
such manner that the gas shall expand into a volume whose pressure does not
exceed that of about one or two feet of water before it enters the treble
connecting tube.
From the description that has already been given of the aerhydric blow pipe,
it will be readily comprehended, that by lengthening the tubes, modifying the
opening of the stopcocks, and changing the nozzles, it will always be very easy
to the operator to conduct the gas and apply the flame darts at considerable
distances from the instrument, to change its form, dimensions, and direction;
to regulate its impulsive force;. to render it oxidating or reductive at will by
burning hydrogen, either pure or mixed, in any proportion with air; and in fine,
entirely to govern its heating power, which can be rendered so intense as to
melt strong platina wire. The following simple test will always indicate with
certainty if the mixture and the force of the current be duly regulated :-In
the affirmative, when the hottest and most reductive part of the interior flame
is applied to a little bit of clean scraped metal,-for example, lead-the heated
point becomes immediately as bright as silver, and the flame itself assumes a
violet tint, produced by the volatilization of a small portion of the lead. And
the negative is shewn (that is, if there be too much or too little air) by the
metal oxidating rapidly, and by its melting upon a much larger surface, owing to
its being heated more slowly. The dimensions, the number, and the disposition
of the flame darts requisite for each particular use necessarily depend on the
nature and fusibility of the metal, and in the thickness and form of the parts
to be united. No other rule can be given on the subject than that the flame
must always be strong enough to melt rapidly the points to which it is applied,
without fusing at the same time the surrounding or neighbouring parts of the

page_text: metal which are to be spared. By a little practice the proper dimensions of
the orifices in each case will be determined.
Before describing the mode of operating for soldering it will be proper to
introduce in this place a description of another apparatus, capable of produc-
ing flame darts, which is not comprehended under the description of the aerhy-
dric blow pipe, but which, on account of its novelty, simplicity, and usefulness,
should be particularly mentioned. It is shewn in Figure 10, Sheet B. Air
forced either by the mouth or in any other way is blown through a flexible
tube 6, into a jet of pure or carburetted hydrogen, which is brought on by a
flexible tube a. These two tubes are of caoutchouc or leather, and are fixed
to brass tubes c, c, united together and covered with woollen cloth, so as to be
used as a handle. d, d, are regulating stopcocks for the air and gas. e, e,
small brass tubes, upon which are screwed copper nozzles inclined to one
another, and having one or more holes. f, a screw, by means of which the
distance between the two nozzles can be regulated at pleasure.
MODE OF OPERATING.
When the two pieces of metal,-lead for example,-are to be united, their
edges are to be scraped clean and bright, and placed in contact. The flame dart
is then to be directed by the operator, in such a manner that the internal sum-
mit of the cone of fire (which is the hottest and most reductive part of it) shall
strike and rapidly heat at the same time the two nearest points of each piece
of metal; the heated points melt separately at first, but the liquifaction
becoming soon complete, they unite into a bright silvery-looking globule.
The agglomeration is then continued gradually onward along the seam or
gutter by similar treatment, and by the mechanical force of the current of
fire the fluid metal is at the same time spread sideways, and as it were pushed
along the gutter, until it is of a uniform and sufficient thickness, feeding, if
needful, the channel with fresh strips of lead, by pushing their extremities into
the flame dart, or by melting some of the lead near to the seam (if it can be
spared) by means of the flame and therewith pushing it into the desired spot.
In order to keep the opposite parts of the two edges that are being acted upon
equally fluid, the flame, by a slight oscillatory but quick motion of the hand,
is made to attack the edges alternately, and as the liquid metal fills up the
channel, and is smoothed down by the stream of fire, the operation is carried
forward until complete, when it presents a surface scarcely different from the
smoothest untouched parts, and incapable of being distinguished from them
after scraping over the surface, being in fact one homogeneous piece of metal.
The work is greatly facilitated in most cases by previously cutting, filling, or
beating down the two parts which are to be soldered, so as to form, when

page_text: applied to each other, a rectangular channel, as is exhibited in the group of
examples marked Figure 11, Sheet B. At a, a, are shewn diametrical
sections of the ends of two leaden pipes so prepared, and intended to be united
in a horizontal position. The ends (scraped clean) being brought into contact,
they are acted upon by the flame dart in the manner described, so as to unite
their extreme edges first on the upper side, and as the work proceeds gradually
turning the tube round until the circle is completed; then the channel may be
filled up with leaden rods or bands, melted in by the aid of the fire dart. In order
to unite two leaden pipes in a vertical position, the edges are advantageously
prepared in the manner represented at b, b. In this case the union is best
effected by dissolving the superfluous projecting portion of the upper tube, and
therewith filling up the groove completely. An example of the mode of joining
two flat surfaces edge to edge, is given at c, c. The bottom of the groove formed
between them is first to be melted, and united, and afterwards filled in, as
already sufficiently explained. The letters d, e, f, g, exhibit four other
examples of the mode of uniting metallic plates at their edges, in all of which
the process of melting down either or both of the edges of the gatter is recom-
mended to increase the thickness of the joints. When flat solderings are to be
made, and can be supported by means of sand, sheet iron, or in any other
manner, it is unnecessary to take all the precautions afore described, and it is
then sufficient to melt rapidly both edges upon the supporter to a state of
complete fluidity, by means of a strong flame, and to add at need the lead
wanting to give to the whole metal a uniform thickness. Asbestos supporters
can in some cases be most advantageously employed as able to take exactly
the form of the under part of the pieces to be supported.
Figure 12, Sheet B, exhibits a mode of uniting thin sheets of lead in a
vertical position. The union is in this case commenced from the upper part
downwards, fusing the deepest parts first, and afterwards melting and bringing
down the edges carefully over the first melting, so as to produce by this
process a thickness in the joint equal at least to that of the other parts of the
lead. In uniting vertical leaden sheets from a twelfth to half an inch or
more in thickness, the fusion and union must be begun at the lower part,
according as the operation proceeds, and the lead which may be required to
give sufficient thickness to the joint is added, and supported by means of a
narrow iron spoon and iron delineated at Figure 15.
Figure 18, Sheet B, represents three examples of this operation. i, i,
exhibits the mode of making a flat vertical fused joint, with a soldering iron j
of a suitable form in front, and an iron support k at the back. 1, 1, exhibits
the mode of operating, when the junction is to be made in an internal angle,

page_text: and the form of the iron m, which is employed to assist in the work; the angular
space n, left open between the face of the iron and the leaden plates, is to
be filled up with lead fused in conjunction with the edges. o, o, shews the
arrangement for making an external angular joining. In this case the
soldering iron p is placed externally, and a supporting angular piece of iron q
placed internally. The cavity r is in this case to be filled up with lead,
fused in conjunction with the edges o, o. The irons j, m, p, are only a few
examples of a variety of forms which, to do the work with facility, efficiency,
and dispatch, should of course be adapted to the figure of the parts to be
operated upon.
At Figures 14 and 15, Sheet B, are shown the details of the soldering
spoon and iron, Figure 14 representing the spoon s sideways, fixed above the
iron m, and Figure 15 gives an upper view of the spoon, with the iron under-
neath. t is the handle. While the spoon of this compound instrument delivers
the lead melted upon it by the flame dart, the iron is applied to support
the fluid metal, and as fast as it consolidates the iron is worked upwards, and
fresh fluid metal discharged from the spoon into the angular space formed
between the lead and the iron, and the operation is thus continued upward
until complete. It frequently occurs that leaden pipes have to be united
which lie in an horizontal position, and cannot be moved. The best method
of performing this is to solder the lower part of the tube's circumference
internally, and then to finish externally the. upper part. Several variations.
may be introduced into the detail of the operation, but the Inventor recommends.
the following, which are illustrated in Figure 16. It consists in cutting away
a sufficient segment of the upper part of the pipe to introduce the flame jet
between them. The two edges at vare then soldered internally, and the
remaining guller filled up with lead, the angular and curved piece w made
to fit the parts cut away from each, and the edges scraped clean, it is put into
its place and soldered to the other parts by means of the flame dart, adding
if needed fresh molten lead to strengthen the joint. A variation from this
consists in making up the upper part of the circumference, which has been cut
away, by means of a thin support a of sheet iron adapted to the internal curve
of the pipe, and upon which fresh lead is melted and modelled by the soldering
iron to the configuration of the pipe, until it is complete, excepting a narrow
slit through which the thin iron support is drawn out; the slit is then filled up
by means of the flame dart, and fresh lead added if required. Thus are
produced, in the most difficult of situations, perfectly homogeneous and at the
least equally strong with the rest of the stracture. Similar modes of operating
are applicable to angular tube soldering, and to a variety of cases which it

page_text: would be tedious to exemplify and detail, but they are such as any plumber of
ordinary intillect and experience will know how to treat after having informed
himself upon the matter of this Specification. The small iron spoons already
described are especially requisite in adding the additional melted lead to
particular points of perpendicular or inverted surfaces. Leaden drops must in
that case be completely melted upon the spoon, and regularly fushed, by the
force of the flame dart against the parts where they are to stick, and which
have previously been well scraped and heated. Iron screens are likewise used
in order to protect the thin neighbouring parts against the effects of two violent
a heat, and they are sometimes employed to retard the fusion of one of the
edges if they are of various thickness, or belong to leaden pieces of very
different magnitude. It is indispensable to the execution of good work that
the operator shall have the advantage of a good light, especially in soldering
the inside of pipes and vessels; and the best ordinary flame jets employed in
soldering give but a free light; now a powerful light of a yellow color is readily
obtained by the addition of a little soda to the gas nozzles, (a fact known to
many chemists, but of peculiar value in an art like this, as it produces the
light necessary for executing the work, concentrated on the exact spot required.
It is an important fact in the economy of this Invention, through perhaps too
obvious to the generallity of readers to require stating, that instead of the
addition of pure lead in all cases, lead alloyed with any proportion of tin may
be used, but it is dearer, and newer succeeds as well. By attention to the in-
structions herein given, with flame darts properly adjusted in the proportion
and impulsive force of their gases, and with a very little practice, every variety
of soldering or uniting the more fusible metals will be executed in a superior
style of neatness and solidity, horizontally, perpindicularly, and even envertedly
in some cases, and upon metals of all forms, dimensions, and thickness.
This system of soldering is generally applicable to all the uses of the plumber
and the pewterer, but there are a few which I deem it proper to notice
particularly, viz.-The forming of leaden chambers, boilers, reservoirs, and
vessels of every description exposed to the action of acid or saline substances
which attack the ordinary solder; for coating internally with thin lead
casks, barrels, boxes, or any other vessels whatever designed to transpor
solid, liquid, or gaseous substances; for joining end to end, and in every other
manner, water pipes, gas pipes, &c. &c.; and it is particularly applicable for
making very thin lead tubes of all dimensions, either with rolled or "old lead'
recast. Flame darts produced either by the aerhydric blow pipe, or obtained
from any other source, but so disposed as to be applied at any required distance
and in every direction as fire tools, by means either of flexible tubes or

page_text: of convenient joints provided with regulating cocks, can be employed not
only for the uniting of lead and other very fusible metallic substances before
named without soldering alloy, but may likewise be advantageously
employed for the solderings of jewellers, braziers, button makers, pewterers,
and other manufacturers in metal, who use the common or the enameller's
blow pipe, or jets of combustible gas, pure or mixed with air. This manner
of applying and handling the flame darts as fire tools, will render them also
capable of being efficaciously substituted in various arts for the usual soldering
irons for soldering tinned iron, tinned brass, tinned copper, tinned silver,
silver, zinc, and lead, not only with the common soft solders, but with solders
much less fusible than those at present in use, and even with lead. The alloys
or metals employed as solders should be either in drops or clean scraped rods
or bands, which are melted on the metal, and directed by means of the interior
flame jet, instead of the soldering iron. Great care should be taken not to
overheat the metals so as to burn the tinned iron, or melt the lead or silver.
Resin, muriatic acid, or sal ammoniac, either solid or dissolved in oil, will be
employed for those solderings in the ordinary way. It follows from what has
been stated, that by this method lead in sheets or in tubes can be soldered or
united to the several metals before enumerated, without any alloy, by simply
scraping very clean the part of the lead which is to be united, applying it in
close contact to the other metal, and melting it by the flame dart. In uniting
tinned copper and brass with lead, it will be preferable to heat the under or
neighbouring part of the copper or brass, and not directly the lead. This
method of applying the flame darts will be particularly useful for soldering
copper, brass, and wrought and cast iron tubes and pipes or cocks with leaden
pipes, or uniting them by intermediate short pieces of leaden tubes, as is
represented at Figure 17, Sheet B. The ends of the tubes A, A, upon
which the soldering is to be executed, should be first tinned in the ordinary
manner, and inserted into the short leaden tube b, previously scraped clean or
tinned inside, and washed in either case with sal ammoniac. The heat of one
or more strong flame darts, according to the dimensions of the copper or iron
piece, is then directed regularly all around the part of the copper or iron which
has not been tinned, and at one or two inches distance from the lead, in
order that the latter metal may not begin to melt before the tinned copper
or iron surface is sufficiently hot to form with it a complete and solid alloy.
The soldering is effected the moment the ends of the piece of lead tube melt all
round. When this process is practised, and particularly when the lead has
not been tinned, the best way is to place the two pieces to be soldered perpen-
dicularly, the lead being downward. In addition to the before described modes

page_text: of soldering, I propose to economize the ordinary process of manufacturing
brass, copper, and other tubes that are soldered longitudinally, by fixing
parallelly a series of them on a suitable carriage, and causing the said carriage
to be brought gradually under the operation of a series of flame darts, at and
immediately over the central line of each tube whereon the solder is laid, in
the ordinary way to be fused, so that the soldering of all the tubes may take
place at once. In the case of making lead tubes in this manner no solder
need be used, but only their edges are to be so brought up as to leave a little
ridge to be melted down, and fill up the fissure without decreasing the thick-
ness of any part of the. tubes. I likewise intend to employ the reverse
operation, especially where the space for the machinery is restricted, that of
fixing the tubes in their parallel and horizontal positions, duly prepared for
soldering, and to cause a series of flame darts emanating from a transverse
tube to traverse over them, and fuse the hard solder, or the superfluous lead
of the lead pipes. The mechanism to produce these results being common to
a great variety of machinery, such for instance as sawing and planing machines,
the draw benches for drawing lead pipes, &c., no particular description is here
given. Flame darts produced in any way may be very advantageously employed
to heat soldering irons to any required degree, and maintain that temperature
constantly during the progress of any work. For this purpose the irons are to
be made either flat or hollow, and to be acted upon either laterally or
internally by one or more flame darts connected by means of flexible
tubes to the gas apparatus, and provided with stop cocks and nozzles for
the regulation and application at the workman's will of the intensity of
the heat and the impulsive force of the flame, likewise to convey and apply the
heated iron to any distance within the limits of the flexible tubes. Figures 1
to 8, Sheet B, represent a few angular, flat, conical, or cylindrical soldering
irons, constructed upon these general principles. A is a long flexible tube
communicating with an aerhydric blow pipe. B is a tube of earthenware, to
one end of which the gas tube A is fixed, and which is used as a handle to
the soldering iron. C is a brass tube fixed to the other end of the tube B.
D, a sheet iron or copper soldering iron, through a hole in which the tube C
passes. E, screws, by means of which the soldering iron is made fast to the
tube C. F, nozzle perforated with small holes O, (from one fiftieth to one
twelfth of an inch in diameter), out of which the flame darts issue, and which
can, if wanted, be partly stopped with a little plaster of Paris. Figure 9
represents a soldering iron nearly similar to that represented in Figure 1, the
only difference consisting in the heated copper or iron t being disposed so as
to be changed at need by means of the screws s, which preserve at a proper

page_text: distance the two iron sides u, between which t is fixed. Excepting what relates
to the mode of heating soldering irons of this kind, they are to be used in
precisely the same manner as the common soldering irons are at present
employed by plumbers, tinmen, and other workmen.
In witness whereof, I, the said Luke Hebert, have hereunto set my
hand and seal, this Twenty-seventh day of November, One thousand
eight hundred and thirty-eight