IMPROVEMENTS IN THE CONSTRUCTION OF PIANOFORTES
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
ERARD, of Paris, send greeting.
,',
1.
WHEREAS did, by Petition, humbly represent unto Her present most
Excellent Majesty Queen Victoria, that I had invented "IMPROVEMENTS IN
THE CONSTRUCTION OF PIANOFORTES," and Her said Majesty, being willing to
give encouragement to all arts and inventions that may be for the public good,
was graciously pleased, by Her Royal Letters Patent under the Great Seal
of the United Kingdom of Great Britain and Ireland, bearing date at West-
minster, the Twelfth day of September, One thousand eight hundred and fifty,
in the fourteenth year of Her reign, to give and grant unto me, the said
Pierre Erard, my exors, admors, and assigns, Her especial license, full power,
sole privilege and authority, that I or they, by myself or themselves, or by
my or their deputies, servants, or agents, or such others as I or they should
agree with (and no others), during the term of fourteen years from the date
of the said Letters Patent, should and lawfully might make, use, exercise,, and
vend my said Invention within that part of Her said Majesty's. Dominions
called England, Her Dominion of Wales, and Town of Berwick-upon-Tweed,
in such manner as to me, my exors, admiors, and assigns, shall seem meet,
and that I or they shall enjoy the whole profit and advantage arising by
reason of the said Invention during the said term of fourteen years; and
whereas the said Letters Patent contain a proviso obliging me, the said
Pierre Erard, particularly to describe and ascertain the nature of my said
f +
A

page_text: Invention, and in what manner the same is to be performed, by an instru-
ment in writing under my hand and seal, and to cause the same to be
inrolled in Her Majesty's High Court of Chancery within six calender months
next and immediately after the date of the said Letters Patent, as in and
by the same (reference being thereunto had) will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Pierre Erard, do hereby declare that my said Invention, and the manner
in which the same is to be performed, is described and ascertained in manner
following, and by the aid of the thirteen Sheets of Drawings hereunto
annexed, with the writing thereon, that is to say :-
The improvements which constitute the present Invention are various, and
may be applied to pianofortes of different forms, whether they stand upright
or to those which are horizontal. Before entering into the detailed explana-
tion it may be well to state that since my establishing in England the
manufacture of Sebastian Erard's repetition action for pianofortes, under the
Patent granted to me the Twenty-second day of December, One thousand
eight hundred and twenty-one (the term of which Patent was extended by a
further Patent dated the Thirty-first of December, One thousand eight hun-
dred and thirty-five), those instruments have been carried to such a degree
of perfection for the flexibility and precision of touch and the fine quality of
tone, that Erard's grand pianofortes may be said to leave nothing to be
wished for to satisfy the great performers on that instrument; and as far as
the solidity of their construction is concerned, the other improvements intro-
duced, in their general construction, as partly specified in my Patents of the
Fifth day of January, One thousand eight hundred and twenty-five, and the
Twentieth day of February, One thousand eight hundred and twenty-seven, had
insured for, them. very satisfactory durability; notwithstanding, the experience
acquired during a period of twenty-five years in making and exporting those
instruments to the various climates of the globe has led me to make the
further improvements which are the subject of the present Patent, the prin-
cipal object of which is to render pianofortes in general better suited for
extreme climates, where the noxious influences of damp and great heat
exercise a destructive effect on the most seasoned woods, and tend to dissolve
the best glueings, hence the necessity taught by experience to substitute as
much as possible metal for wood in the construction of pianofortes, especially
in those parts of the instrument which are more or less acted upon by the
tension or pull of the wires. For twenty-five years past it is true the use
of metal has been effectually introduced into different parts of Erard's grand

page_text: pianofortes, such as the metallic bracing of six or more iron bars over the wires,
and the improved hitch pin plate of metal, also the harmonic metal bar,
&c., &c. Notwithstanding the good result attending the introduction of metal
in various parts of the instrument something more remained to be done,
namely, to unite those partial additions of metal into one general system so as
to combine them into an entire frame of resistance sufficiently firm and secure
to resist in a more efficient manner the great pull of the wires. Numerous expe-
riments have been made by me from time to time in order to obtain such a
desirable end; and after much labour, trouble, and expense, I have succeeded
in producing a new mode of applying metal to the construction of pianofortes
comprising the indispensable qualities of strength, durability, lightness, and
facility of application. Besides those improvements which bear upon the
general construction of the instruments, I made others on the mechanism and
action of the instruments. To make this Specification more distinct and clear
I shall divide the description of those improvements into parts.
Part the First.. Improvements on the general Construction of the Instru-
ment. Hitherto it has been a general practice in pianoforte making,-when-
ever metal has been introduced for strengthening different parts of the instru-
ment, to fix the auxiliary metal to the wood. Now the principal novelty of this
first part of my present improvements is the reverse, namely, the application
of wood to metal, as I shall proceed to explain in the description of my new
invented wrest plank, which part of the instrument is the most difficult to
construct in grand pianofortes. In the ordinary construction of those instru-
ments the wrest plank, when applied to the sides of the case, in order to form
that part of the instrument called the frame, is made entirely of wood, and it is
only when the case is built together that the different pieces of metal requisite
.to strengthen or secure it are applied to the wood, but in my new improved
.construction the metal is the basis of the construction, and the wood is applied
to the metal so as to form the wrest plank. previous to its being fixed to the
sides of the case or frame in the following manner :-
New Constructed Wrest Plank applied to Horizontal Grand Pianofortes.-.
In the different Figures of the Drawings the same letters denote the same
things, and the writing on the Drawings will assist the following description:-
In Sheet I., Figures 1 and 2 represent the two separate parts of my new
improved wrest plank for a grand pianoforte, ready shaped and prepared to
be united together to form a whole previous to the wrest plank being fixed to
the frame or case of the pianoforte. Figure 1 is the metal part-which must be
made of cast metal. Figure 2 is the wood part, which may be made of any
: suitable wood, beech by preference. Figures 3 and 4 are edge views of the
A 2

page_text: two parts, metal and wood, of the wrest plank, ready to be joined one to the
other. The edge of the wood, Figure 3 (which Figure represents the wood
part inverted) is fitted into the groove-shaped metal, Figure 4. Figures 5
and 6 are end sections of the same two parts. Those two parts are joined
one to the other in such manner that, by uniting the two parts, the line a, a,
Figure 1, of the metal part is brought into close contact with the dotted
line b, b, Figure 2, at the under side of the wood part, and the line c, c, of the
wood is brought into close contact with the line d, d, of the metal, Figure 1;
and the two parts, when so fitted and joined to one another as they appear in
Figure 7, form my new improved wrest plank. Figure 8 is an end section of
my new wrest plank, at that end which is to be fixed to the treble side of the
case of the instrument; and Figure 9 is an end section at the other end, which
is to be fixed to the base side of the case of the instrument. These two said
Figures shew the flanged shape 9, 9, into which the metal part is cast at
both ends, in order that it may be firmly secured by screwing to the two sides
of the case, both below and above the level of the wrest plank, in order to
give it an additional steadiness, whilst the wood part of the wrest plank is
joined or pinned to the sides of the case. The projections of the metal part of
my new wrest plank, Figures 1 and 7, have upright parts h, h, to serve as
abutments for the front ends of the metallic bar i, forming the bracing of the
instrument; and holes are made through those projections to receive upright
bolts k, Figure 8, with square heads above the projections, fitting closely to
the said upright parts h. The ends of the said metallic bars are fitted and
fastened by upright screws to the said square heads of the bolts k, which have
screws on their lower ends to receive metal nuts countersunk into the under
side of the metal part of the wrest plank; and the bolts k answer, as is shewn
by Figure 8, the double purpose of securing firmly the grooved shape of the
metal part to the wood part, and at the same time of supporting and securing
the bracing metallic bars i in an efficient manner at their front ends on the
wrest plank. The opposite ends of the bracing metal bars are fixed in the
usual manner to the metal plate called the hitch pin plate, to which those ends
of the wires which are opposite to the wrest plank are attached, the wires
are therefore attached at both ends to proper metal stops, united and kept
apart by means 'of a sufficient number of longitudinal bracing bars i, i, these
three distinct members, metal wrest plank, hitch pin plate, and bracing bars,
forming a solid frame, which sustains the pull of the wires almost independently
of the wood frame or sonorous case of the instrument. The row of small
circles e, e, and e, e, upon the metal part, Figures 1 and 7, show the places
where the usual bridge studs are screwed into the metal.
The studs are

page_text: made of suitable metal to serve as vibrating rests for the wires; such
metal studs were originally introduced in Sebastian Erard's pianofortes, and
have proved such a beneficial improvement to pianofortes where the hammers
strike upwards beneath the wires, as is generally the case in horizontal grand
pianofortes,. that such studs have been generally adopted through the trade, but
fixed in the ordinary. wood' wrest plank. Now it is evident that their efficiency
must be carried still further when properly applied and firmly fixed to metal,.
for experience has proved that the firmer the wires are fixed to the ends of
their vibrating lengths the purer are the tones. f,f, Figures 7, 8, and 9,
is a brass plate of a proper thickness, properly glued and fixed by screws
to the wood part of the wrest plank, Figure 2, to give still more firmness
thereto. The holes through the plate f. f. for the tuning pins or wrest
pins to pass through. into the wood beneath, must be of a somewhat larger
diameter than that of the tuning pins... Such a plate as f,f, having been.
applied to wrest planks before,. I do not claim it as part of my Invention; it
is merely shewn here as applied in a more effective manner from its edge
bearing against the projections. of the metal part, Figure 1, of the wrest
plank, as shewn in. Figure 7, which renders the whole more firm and solid
than when merely built of wood. On the other edge the thickness of the plate
is reduced with a bevil edge so as to come come flush with the horizontal part
of the wood in front of the wrest pins suitably for that bevil edge to be covered.
over by what is technically called the capping piece of the wrest plank, as is
clearly shown in Figures 8 and 9. It is obvious from the Drawings and the
foregoing description that the pull of the wires principally falls upon the metal
part of the wrest plank, the wood being introduced in this construction of the
wrest plank merely to receive the ordinary wrest pins, which are inserted into
holes in the wood beneath f, f, in the usual manner. This improvement of.
the application of metal instead of wood in the wrest plank may be carried
still further by making the wrest plank entirely of metal, which new construc-
tion will require the application of a new and more mechanical system of
tuning, as is herein-after described.
New-constructed Wrest Planks applied to Horizontal Pianofortes, of other
Forms than Grand Pianofortes.-It may be easily conceived that a wrest
plank on my new construction may be applied to pianofortes of all forms by
introducing such alterations in the form and application of it herein-before
described as may be required to suit the difference of construction in the
instrument. Sheet II. represents the treble end of an horizontal pianoforte of
the square construction, where the useless corners, taking up much room in
the apartment, are removed in the manner shewn by the plan Figure 10, the

page_text: But
dotted lines representing the old square shape of one of the corners.
whatever shape may be adopted, which is a matter of taste and convenience,
the improved construction hereby to be described may be applied in the
following manner :--Figure 10; Sheet II., is a horizontal plan, and Figure 11'
a vertical section, of the treble part of a square pianoforte with three unison
wires for each note in the scale. Figure 10 shews the compass of thirty-three
notes only in the treble of the instrument, but will suffice to shew the appli-
cation of my new wrest plank. A, Figure 11, is a section of the metal part
of tlie wrest plank, in which are cast certain projections to form abutments
for one end of each of the longitudinal bracing bars i. The other ends of those
bars are affixed to the upper ends of upright bolts of a conical shape, whereof
three are shown at e, e, e, for as many of the bracing bars i, i, i. The bolts
pass through holes in the metallic hitch-pin plate, and are driven down
through those holes into the cross rails of the wood frame, and also down into
the frame bottom below 'at the under part of the instrument with a consider-
able force. The metallic part A of the wrest plank is formed with the
flanged shape shewn at A, Figure 11, so as to admit of the wood part of
the wrest plank being fitted behind and beneath it, and fastened to the
wood by screws, as shewn in both Figures. Figures 10 and 11 will suffice
to shew in what manner the metal part A of the wrest plank, metal hitch-pin
plate, and the metal bracing, bar i, i, are combined together to form a frame
for the treble' part of the instrument, and such combination may be continued.
in like manner throughout the remainder of the instrument. Those three
members united together form, as in the grand pianoforte, Sheet I., a frame
for resisting the greater part of the pull of the wires. f,f, is the brass plate,
that may be added at pleasure on the wood part of the wrest plank behind
the metal part A thereof, where the wrest pins are inserted nearly in the
same manner as in the grand piano, Sheet I., with one of the edges of f,f,
bearing against the edge of the metal part A of the wrest plank.
New-constructed Metal Bracing Bars and Wrest Plank applied to Upright
Pianofortes. In upright pianofortes the upright wood rails forming the
principal part of the wood frame at the back of the instrument are not inter-
rupted, as is the case in most horizontal pianofortes, and hence the application
of metal bars in front of the wires has not been felt to be so necessary in
upright as in horizontal pianofortes, where such wood rails of the frame must
be interrupted, and, in consequence, that frame considerably weakened, in
order to allow space for the hammers to move towards and strike the wires;
and, furthermore, upright pianofortes have been almost invariably strung with
two unison wires only for each note in the scale of the instrument so, as to

page_text: abject the framework to much less pull of the wires. In my improved
pright pianofortes (either with the wires disposed perpendicularly or obliquely).
generally avail myself of three wires to each note, and adopt such a compass
the lengths of the wires as will insure. a more powerful tone and more
quality of tone throughout the scale than is usual in upright pianofortes; in
onsequence the pull of the wires is considerable; and I have found the appli-
ation of such bracing bars indispensable for good and durable instruments...
The quality and power of tone of a superior pianoforte depends essentially on..
he amount of pull of wires that its framework and case will resist effectually.
Experience has proved that the fineness and intensity of the tones depend
materially upon a good proportion between the lengths and the diameters of:
the wires employed throughout the scale of the instrument, and without the -
aid of counter-bracing bars in front of the wires it would be impracticable.to.
construct a sonorous case sufficiently strong to resist the pull of the best.
proportioned wires so effectually (when there are three wires to each note) as
to insure the instrument standing. in tune, even with the aid of those well..
known contrivances hitherto employed for strengthening the wood frame.
behind the wires by the application of metal to the wood at the back of the
instrument. I therefore claim, as an important improvement in the construc:
tion of upright pianofortes, the application of additional bracing to the frame
work and case of upright pianofortes in general by means of metal bracing
bars applied in front of the wires, that being the same side of the wires. where
the hammers strike them. The application of such bracing bars upon that
side of the wire where the action with the hammer must be placed to strike.
the wires presented great difficulties to carry it into practice, and. it. is. not.
until after much labour and repeated experiments that I have succeeded in.
applying such metal bracing bars in a practicable and effective. manner
in upright pianofortes. I shall now proceed to explain the manner in which
I make the aforesaid application.
Sheets III. and IV. represent sonorous cases of upright pianofortes strung
with wires in two different modes, but both those cases being on my new mode
Sheet III.
of bracing with metal bars in front of the wires of the instrument.
is the sonorous case of an upright pianoforte, where the wires are disposed
obliquely to a vertical position, although all the wires are in the same vertical
plane. And Sheet 1V. is the sonorous case of an upright pianoforte wherein
the wires are disposed in a vertical position and all of them in the same vertical
plane. Although the nature of the improvement is the same in both instru-
ments, yet the application to each sort of instrument requires particular
adaptation. In Sheet III. Figure 12 is a front elevation of the sonorous case

page_text: of a pianoforte with oblique wires, having four metal bracing bars i, i, applied
to it in the same oblique direction nearly as the wires that are adjacent to each
bar; namely, one of those bars, No. 1, is close to the wire for the lowest bass
note of instrument; the next bracing bar, No. 2, see also Figure 13, is placed
in front of a narrow space left between the uppermost of those bass wires which
are covered with a coiling of other wire, and the adjacent naked wire. The
bracing bar No. 3 (also Figure 14) is applied at that place of the scale of the
instrument where the dampers begin to be omitted. The bracing bar, No. 4,
is placed beyond the wire for the highest note in the treble. Each of the
bars i, i, is nearly but not quite parallel to those wires which are adjacent to
the bar on each side thereof. It is obvious that a greater number of such
bracing bars i, might be applied in front of the wires of an upright pianoforte
without affecting the nature of my application of bracing bars to upright
- pianofortes, but in my estimation four bracing bars are sufficient to insure to
pianofortes of that description all the solidity which they stood in need of; such
an application of bracing bars to upright pianofortes is not practicable unless a
greater space is left between the wires in the general scale of the wires of the
instrument, at each of those places where such a bar is to be placed before
the wires or rather before such space between the wires, this is clearly shewn
in Sheet III., which represents an instrument of the complete compass of
seven octaves from the notes A to A. The bracing bar No. 2 (see a side view
thereof, Figure 13) is placed in front of such a space which is left between the
lower ends of the wires for the notes 22 and 23, nevertheless the usual scale
of spaces is followed for the upper ends of the wires where they are retained
by their bridge stud e, e, Figure 12, which studs are there represented to be
metal studs with holes through them for the wires, in the manner herein-
before described, and such as were introduced by me in grand pianofortes.
But owing to the wires for the note 22 not being parallel to the wires for the
note 23, the space between those wires is greater below than at their studs e, e,
and along the red line v, w, Figure 12 (which denotes the places where the
hammers strike the wires all through the whole scale of the instrument) a suffi-
cient space is left between the said wires for the notes 22 and 23 to admit of the
bracing bar No. 2 being placed in front of that space without interfering with
either of the two hammers which belong to those wires. The 'said space
between the wires for the notes 22 and 23 is greater at the bridge on the
sounding board, and still greater at the lower ends of those wires where they
are attached to their respective hitch pins. In like manner a space is left in
the row of the studs e, e, between those studs which belong to the wires for the
notes 64 and 65; those wires are parallel one to the other, and allow a sufficient

page_text: space between them for the bracing bar No. 3 to be placed in front of that
space without interfering with either of the hammers which belong to the wires
for those two notes. Figure 14 is a side view of the bracing bar No. 3, and
shews that there is a notch cut out in the front side of the bridge upon the
sounding board, which bridge must be properly strengthened by bracing under
the sounding board; the two ends of the said bar No. 3, are fixed by bolts passing
through the wood frame at the back of the instrument and through my improved
metal wrest plank, in case the same is used, as shewn in Figures 16, 17,
and 18. But in case such improved wrest plank is not used, then the upper
ends of the bracing bars No. 2 and No. 3 are fixed either by screw bolts
passing through the ends of the bar and through the wood of the usual wrest
plank, as appears in Figures 12 and 14, for the bracing bar No. 3, or else by
five small screws passing through lateral projections at the upper ends of the
bracing bars No. 1 and No. 2 (as appears in Figures 12, 13, and 19); and
those screws screwing into the wood of the usual wrest plank, and near the
lower ends of the bracing bars No. 2 and No. 3, the hitch pin plates are
fastenened to them by screws, the plate being notched into the under edges of
the bracing bars, as shewn in Figure 14, so as to abut firmly against the
notches which are cut across at right angles to the lengthways of the bars.
There are two hitch pin plates, as shewn in Figure 12, a small one containing
the hitch pins for all the covered wires of the bass, and a larger hitch pin plate
containing the hitch pins for all the naked wires in the remainder of the
compass of the instrument. Those two hitch pin plates are well united together
by dovetailing at their lower parts where they meet together, and the bolts for
fastening the lower part of the bracing bar No. 2 passes through the large
hitch pin plate near to the said dovetailing, as appears in Figure 12. The
bracing bars Nos. 1, 2, and 3, are further secured in their lengths by means
of screws r and s, which pass through those bars and are screwed into the
wood frame of the instrument at proper places; some of those screws r, r, for
the bars No. 1 and No. 2, pass through holes in the sounding board, and
another screws, for the bar No. 3, see Figures 12 and 14, is screwed into the
metal hitch pin plate, and serves to unite the bar to that plate, and also to keep
that plate at its proper distance from the sounding board, which is behind the
said plate. The bracing bar No. 4, Figures 12 and 15, is very short, and serves to
keep the upper end of the large hitch pin plate at its proper distance from the
wood wrest plank, or from my metal wrest plank, in case the latter is applied
to the instrument. Figure 13 shews the curved shape that the bracing bars
Nos. 1 and 2 must have to be fitted for their respective places in the instrument,
as they must be kept at a proper distance near the plane of the wires on the

page_text: instrument, to allow the action to be placed in its proper place in front of those
wires. The bracing bars are wrought iron, made of a suitable shape by drawing
(in the manner of wire) so as to give the metal stiffness; but in order to allow
of the upper ends of the several bars being properly shaped to obtain firm abut-
ments on the wood wrest plank, those upper ends may be made of cast iron
suitably shaped, as in Figures 13 and 19, and fitted to the end of the wrought
iron bar with a scarf joint, as shewn in Figure 13, and that joint secured by
brazing, so as to make the bars complete, in required shape and form. This
mode of making them will facilitate the application of such bars to the
usual wood wrest plank. But in case my new metal wrest plank is
applied, as in Figures 16, 17, and 18; then suitable projecting parts must
be cast in the metal part of that wrest plank itself to receive and form secure
abutments for the upper ends of the several bracing bars i, i, which ends are
fastened to the front side of the metal of the new wrest plank, in the manner
shewn in Figure 16, namely, by two screws for the upper ends of each of the
bracing bars No. 1 and No. 2, and by one bolt for the upper end of the bar
No. 3, that bolt passing quite through the new wrest plank; such mode of
applying the bracing bars will render the framing of the metal parts of the
instrument still more firm and durable. The various Figures in Sheet III.,
with the foregoing description of them, will sufficiently explain the great
advantage of the application of the metal bracing bars i, i, to an upright
pianoforte in front of the wires thereof, those bars being firmly fastened at
one end of each such bracing bar i, i, to the wrest plank, to which the upper
ends of the wires are attached, and the lower ends of the same bars being
firmly connected to the hitch pin plates, to which the lower ends of the wires
are attached. The said application forms altogether a complete and compact
metal frame to resist the greater part of the pull of the wires. That will be
the case even although such bracing bars are applied to a wood wrest plank
only, as in Figure 12. The great security and strength they give to the
instrument is obvious, as they secure to upright pianofortes the great advantage
of having two planes of resistance between which the plane of the wires is
situated, with the same beneficial result as already stated to be obtained in
pianos of the horizontal construction, but in a still more efficient manner,
because the two planes of resistance are much nearer to the pull of the wires
than can be practised in horizontal pianofortes; and, therefore, by my new
application of metal bracing bars to the upright pianofortes in front of the
wires thereof, those instruments may be rendered quite as firm and durable
as horizontal pianofortes. Sheet IV. shows my new application of bracing
bars i, i, to an upright pianoforte, whereof the wires are disposed perpendi

page_text: cularly, the compass of the instrument being six and three quarters octaves
from note C to note A. Those bracing bars i, i, are applied nearly in the
same manner in front of the wires as in the upright pianoforte with oblique
wires, already described in reference to Sheet III., that is to say, proper spaces
are left between the wires at those places in the scale where such bracing bars
are required to be placed between the wires which belong to two notes.
In
the instruments, Sheet IV., the bracing bar No. 1 ang parallel to the wire for
the lowest bass note in the scale, which wire is itself parallel to the side of the
case of the instrument; and to render that bar, No. 1, more firm, it may be
secured fast to that side of the case. The bracing bar, No. 2, is placed
between the wires for notes No. 27 and 28. The bracing bar, No. 3, is placed
between the wires for notes 60 and 61 where the dampers leave off. The
bracing bar, No. 4, is placed beyond the wires for the highest note in the
treble, and acts as a stretcher between the hitch pin plate and the metal part
of the new wrest plank. Proper spaces must be left in the scale of the wires
to allow room for the several bracing bars to stand between the wires for the
notes 27 and 28, and the wires for the notes 60 and 61, so that the said bars
will not interfere with the hammers belonging to those bars respectively; such
spaces can be arranged with greater facility in the instrument, Sheet IV., than
in the former instrument, Sheet III., because the wires in Sheet IV. are dis--
posed upon the same scale of distances apart as the row of hammers and the
action for moving the hammers, which is not the case in oblique pianofortes,
such as Sheet III. It is obvious that a greater number of such oblique
bracing bars might be placed in the instrument, Sheet IV., if required. The
manner in which the four bracing bars are fixed in the pianoforte, Sheet IV.,
is clearly shewn by the different Figures' therein, and the writing on those.
Figures, together with the foregoing explanation of Sheet III., will sufficiently.
explain the application of the bracing bars in Sheet IV., so, that they, together-
with the metal wrest plank and the two bitch pin plates, constitute a solid
and firm metal plane in front of the wires for resisting the pull of the wires
in addition to the resistance of the wood framing behind the wires, so that
the wires are stretched in a vertical plane situated between two planes of
resistance to the pull of those wires, in the same manner as heretofore
explained in reference to Sheet III., and producing the same improved con-
struction in an upright pianoforte, Sheet IV., with vertical wires, as before
stated to be produced in an upright pianoforte, Sheet III., with oblique wires.
By comparing the two kinds of upright pianofortes, Sheet III., with oblique
wires; and Sheet IV. with perpendicular wires, the advantage in point of com:
pass or length of wire in the bass will be found to be in favor of the oblique

page_text: wires, Sheet III., in the proportion that the length obliquely bears to the
vertical height of a parallelogram.
New constructed Wrest Plank, similar to that herein-before described
in reference to Sheet I., but now applied to Upright Pianofortes, whether
the Wires thereof are placed Obliquely as in Sheet III. or Vertically
as in Sheet IV.-Some description has been already given of the ap-
plication of my new wrest plank to an upright pianoforte with oblique
wires, as shewn in Sheet III., at Figures 16, 17, and 18, and all the
Figures in Sheet IV. represent the application of such new wrest plank to an
upright pianoforte with vertical wires. The metal part of each of those wrest
planks, Figures 16, 17, and 18, Sheet III., and Figures 21, 22, 23, and 24,
Sheet IV., is cast in one piece of metal with openings, as shewn in Figure 16;
Sheet III., and Figure 22, Sheet IV., to render the casting lighter. Figures
17 and 18, Sheet III., and Figures 21, 23, and. 24, Sheet IV., are sections of
the new wrest plank, shewing the way in which the metal part thereof is fitted
to receive the wood part, which latter is in front of the wood part and is
securely fixed thereto by screws. Those sections also shew that the metal
part is formed with such a projection in front of it as is necessary to constitute
the bridge for the upper ends of the vibrating lengths of the wires, which
wires bear backwards against that projection or bridge, and stud pins vare
driven into the metal in a row along the said projection, one stud pin v for
each wire, as is shewn in Figures 16, 17, and 18, Sheet III., and Figures 22,
23, and 24, Sheet IV. The wires bear backwards against the said bridge and
stud pins (as they do in the ordinary construction of upright pianofortes) in
consequence of the wires bending at a small angle at the several bridge stud
pins. The section of the wrest plank, Figures 17 and 18, Sheet III.,
and Figures 21, 23, 24, Sheet IV., shews the angles of bending backwards
at that is requisite for causing the wires to rest firmly against the
bridge.
Part the Second. Improved Apparatus for Stretching and Tuning the
Wires of Pianofortes, see Sheet V.-Several attempts have been made at
different times by ingenious men to substitute for the wrest pin or tuning
pin driven into the wood of the wrest plank a more mechanical contrivance.
Sebastian Erard directed his attention to the subject when he first began
improving the grand pianoforte, about the beginning of the present century,
and he applied to the wrest plank of one of that kind of pianofortes
a series of screws for tuning in place of the common tuning pins, one
such screw for each wire the lengthway of that screw being nearly in
prolongation of the direction of the wire, with the end of the screw

page_text: bearing against a fixed stop, and the screw when turned round by a key
operating upon a nut tapped to receive the screw through it, that nut being
fitted into a fixed groove, and the end of the wire being attached to the nut
the motion given by the screw to the nut caused the wire to be stretched or
relaxed according to the direction in which the screw ought to be turned
round by its key. This having been done more than forty years ago by
Sebastian Erard, I do not claim the right of using screws for tuning piano-
fortes, but having at different times within the last few years made numerous
experiments upon the application of such screws for tuning, I have succeeded
in producing an improved apparatus to be applied in pianofortes of that con-
struction wherein the direction of the wires range in conformity with the
direction of the finger keys, namely, the grand pianoforte and the upright
pianoforte, with vertical wires. A difficulty attending the application of
screws for tuning was the want of room to place three such screws, with the
necessary apparatus for tuning the three wires belonging to each note in the
scale of the pianoforte, the space generally allowed in the widest scale of
grand pianofortes being barely nine sixteenths of an inch for each note; but
by disposing the three tuning screws and their apparatus for the three wires
to each note in two rows, one of those rows. nearer to the bridge than the
other row, I have succeeded in the aforesaid application. The tuning screws
originally applied by Sebastian Erard were placed in only one row throughout
the scale of the instrument, but the wires used in instruments forty years ago
were so much smaller than are now used, that his original mode of arranging
the tuning screws and apparatus, although permitting of adequate strength
for such small wires, did not permit of making the parts sufficiently strong
and solid to operate with satisfactory efficiency if wires of the modern scale of
sizes for such wires had been used.
-
Sheet V. shews my improved apparatus for tuning by screw adjustment,
drawn full size. Figure 25 is a side elevation, and Figure 26, a horizontal
plan of the tuning apparatus for the three wires.of.one note. In Figure 25
a is the wrest plank of the instrument, made of wood or metal, but more
effectually of metal, because wood is not required for receiving the ordinary
wrest pins, and therefore the wood of the wrest plank may be dispensed with
entirely. e is the bridge, with three holes through it for the three wires of
the same note to pass through. b, Figure 25, is a bearing piece fixed.in front
of the 'stud e for the wires to pass over, in order that they may thereby be
raised so much as to give them a proper bearing upwards on the stud, with
a firm contact of each wire against the upper parts of the interior of the hole
for that wire through the said stud e, in order to retain each of the wires
securely at that end of its vibrating length. The said studs é (which have

page_text: been herein-before mentioned as originally introduced in Erard's grand piano-
fortes, and since generally adopted in grand pianofortes, and the reverse of the
old mode of laying the wires across a wood bridge and bearing laterally
against a sloping pin driven into the wood of that bridge, the bearing of the
wire in such case was downwards and sideways, and not well qualified to
resist the action of the hammer striking upwards beneath the wire, and
required the wire to be bended at a considerable angle against the sloping
pin in the wood bridge and over that bridge. Such bending caused much
friction on the wire, which in consequence resisted being drawn endways in
the act of tuning. With the studs e each of the wires has a firm and
definite. bearing upwards, so as to effectually to resist the upward action of
the hammer, and that with only a small angle of flexure at the stud e, as is
shown in Figure 25, and consequently but little resistance of friction in the
act of tuning. This circumstance is of so much importance that the applica-
tion of a screw for tuning would be almost impracticable without such
studs e, from the great resistance that the wire would oppose in the act of
.being dragged across the old wood bridge and pin. f, f, Figures 25 and 26,
arė sliding nuts, to the uppermost parts of which the ends of the wires are
attached; one. wire to each nut, and the nuts ff, are tapped through their
lower parts to receive the tuning screws h, h. The nuts f, f, are fitted into
the fixed sockets g, g, so as slide endways therein by action of the screws h, h,
which are lodged within the sockets g, g, so as to pass through the tapped
nuts ff; and the screws h, h, have shoulders formed upon them to bear
endways against the front ends of sockets g, g, in such manner that any one of
the sliding nuts f. f, to which one of the wires is attached, will be caused to
slide endways in its corresponding socket g whenever the screw h belonging
thereto is turned round; by application of a small winding up key to the
square at the front end of the said screw k, any one of the wires can be thus
'screwed up to the required tension by a very steady and pleasant motion, and
with so little effort that the force of two fingers applied to the key will
suffice to tune the wire. The sockets g, g, are fixed by being screwed down
upon a fixed plate i, i, which is firmly screwed down upon the wrest plank a,
and a projection across the upper side of i, i, enters into a corresponding
I notch at the under side of each socket 9, 9, so as to retain the latter secure
against any motion endways, and the socket g is held down by a screw at each.
end of it upon the plate i, i, which is itself fixed on the wrest plank a
(either wood or iron) by means of proper screws at each end of i, i, which is
secured from moving endways by abuting at its backmost end against the
abutnient on the wrest plank a, so as to effectually oppose the pull of the
wires. Each of the fixed plates i, i, will serve as a base for as many of the

page_text: sockets g, g, and consequently for as many wires as it may be convenient to
fasten side by side upon one plate i, i, the width thereof being suitable for the
number of the sockets g, g, that are to be fastened upon it. Figures 25 and
26, as already mentioned, represent three sockets g, g, g, fastened upon the
same fixed plate i, i, two of those three sockets g, g, being side by side, but
the third socket g being nearer towards the stud e 'and opposite to the space
between the aforesaid two sockets g, g. The screw h of the said third socket is
prolonged through that 'space, so that the squares on the front ends of all the
three screws for applying the tuning key are side by side. Figure 27 shews
two sockets g, g, side by side, for the case of two wires only to a note.
Figure 28 represents a similar apparatus for only one wire to one note. The
two last, Figures 27 and 28, are intended for wires of the bass note, which
wires are generally covered with a suitable wire wound around them, as shewn
at m and m, Figures 27 and 28, and the covering wire m, m, is not carried
through the holes in the stud e but only the naked steel wire, the end of the
covering wire thereof being made fast upon it by twisting in the end, or by
soldering, so that the covering of the wire will not reach to the stud e, this is
shewn at m, m, in Figures 27 and 28. This new mode of making' the
covering wire fast upon the wire before it reaches the stud e is à great
improvement upon the old method, because the covering wire is not dragged
against the bearing of the wire at the stud e, which dragging would cause the
covering wire to unravel and become loose on the steel wire, so as to produce
a jarring sound; also the intervention of the covering wire at the bearing
against the stud would greatly increase the friction, and consequently the
force requisite för tuning the wire. Figure 29 is a side elevation of the
screw apparatus, Figure 28, for tuning only one wire, the construction being
the same as already described. The sliding nut f projects up out of the fixed
socket g into which it is fitted, and to the uppermost projecting part off the
end of the wire is attached by looping it around the said uppermost projecting
part into a notch cut therein in the manner shewn in Figure 25 as well as
Figure 29.
2-
Figure 30 is a side elevation of a screw apparatus, which is represented to
be for tuning only one wire, similar in application and effect to Figure 29,
but more solid and easy of manufacture. The fixed 'socket g is formed of a
piece of square tube made by drawing in the manner of drawn tube, but of a
square shape, and such tube sawn off into short lengths, the interior of the
square socket being adapted to receive the sliding nut f within it, with the
uppermost part off fitting to the uppermost side of the hollow through the
socket 9, but that uppermost part off having a notch cut out in it for the wire

page_text: to be attached to f by looping around the notched part at the uppermost part
thereof. The said sliding nut f is formed of a short piece sawn off from a bar
made by drawing in the manner of wire, but of a suitable square form and
size to fit truly into the interior hollow of the aforesaid square tube. The
stud h has a shoulder formed upon it for bearing against the front end of the
fixed socket g, which end is formed by a small plate of metal fastened to that
front end, and having a hole through it for the screw h to pass freely through,
the tappet part of the screw being received into the tapped hole through the
lower part of the sliding nut f. The fixed socket g is placed and fixed over a
projection at the upper side of the plate i, i, to which plate the socket is
screwed down by a screw at each end of it. The plate i, i, itself is fixed to
the 'wrest plank by screws, with an abutment j in the manner herein-before
described. The said plate i, i, may have two, three, or more of the sockets g
fastened upon it, as may be required.
Part the Third. Improvements in the combination of parts for Actuating
the Hammers by the Finger Keys, which combination is commonly called the
Action of the Pianoforte; see Sheets VI. and VII., also Sheet VIII.-Twenty-
eight years ago, when I obtained my Patent of the Twenty-second day of
December, One thousand eight hundred and twenty-two, for Sebastian
Erard's repetition action in grand pianofortes, there remained much room for
improvement in the action of upright pianofortes, that part of the action
which is commonly called the check had not at that time been effectually
applied in the action of upright pianofortes, and the hammers, for want of the
check, were liable to rebound towards the wires after the blow, and by block-
ing against the wires to interfere with the freedom of their vibrations in a
manner very prejudicial to the execution of precise music. The intermediate
lever between the hammer and the key, with the check and the sticker for
the hammer mounted on that intermediate lever (part of Erard's said Patent of
One thousand eight hundred and twenty-two), was afterwards introduced in a
novel form of upright pianofortes; that action (whatever its merit may have
been as an improvement upon the different actions then in use in upright
pianofortes) still remained deficient in some points; and my Patent of the
Twenty-fourth day of September, One thousand eight hundred and forty, was
(amongst other matters) for improvements in the action of upright piano-
fortes, some of which improvements have since that time been brought into
use in upright pianofortes manufactured by me, nevertheless such improved
action did not possess the refinement of touch that is inherent in Erard's
repetition action for grand pianofortes, and which is so much in repute with
all eminent pianoforte professors and amateurs. The object of the improve-

page_text: ment now to be described is to introduce into the action of upright piano-
fortes the same refinement of touch as in Erard's grand pianofortes:
Improved Action applied to Upright Pianofortes, Sheets VI. and VII.-
Figure 31, Sheet VI., represents the finger key, and all the parts of the action
in the resting position before the finger has depressed the key. Figure 32
represents the positions into which the finger key and the several members of
the action are thrown by the depression of the key with the finger to the
lowest; the position represented in Figure 32 is after the hammer has been
made to strike the wire so as to put it in vibration, and the escape. of
the sticker i from under the hammer has just taken place, the hammer having
retreated from the wire as far as the check j will allow. Figure 33,
Sheet VII., represents the different positions that the finger key and the
several members of the action will assume by allowing the finger key to
rise upwards in return from the lowest position, Figure 32, towards its resting
position, Figure 31 (that is, towards the level of the other neighbouring keys)
such return being as much as one third of the whole motion that the key has
been previously depressed from the resting position,. Figure 31, in order to
produce the position; Figure 32, and by such return the sticker i has returned
beneath the hammer, as is shewn in Figure 33, in readiness for making
a repetition of the blow of the hammer by pressing down the front end of the
finger key again to its lowest position.
For a full explanation of the different positions of the new action, Figures
31, 32, and 33, I shall describe those positions in detail, as follows:-The
finger key, with its centre of action at a, Figure 33, Sheet VII., and its touch
at 6, has the whole extent of its descending motion at b marked as being
divided into three parts 1, 2, 3. The point of action c at the opposite end of
the finger key communicates by means of the upright pilot f with the inter-
mediate lever g, whereof h is the centre of motion (these parts are shewn
detached in Figure 34) and the sticker i is jointed to the intermediate lever g
to act upwards beneath the hammer d, whereof the centre of motion is at e.
The said intermediate lever g carries the check j for the hammers, as well as
the sticker i, as was the case in my original Specification of One thousand eight
hundred and twenty-two. The sticker i is in the form of an elbow lever, and in
the resting position, Figure 31; the upper end i of the long arm of the sticker:
is beneath the hammer, as is there shewn, but when the intermediate lever g
is raised up, as in Figure 32; by the depression of the key with the finger,
then the short-arm of the elbow lever sticker i is carried up beneath the stop
screw k, and by contact therewith the said upper end of the long arm of the
sticker i-is, caused to escape from beneath the hammer an instant before the
B

page_text: hammer strikes the wire. Au additional lever is applied beneath the inter-
mediate lever g, and both levers g and I are moveable about the same centre
of motion h, although quite independantly one of the other in their motions.
See the parts detached in Figure 34, Sheet VII. At the extreme end of the
additional lever a second sticker m is jointed at n, see also Figure 34, and
that second sticker m reaches up to the hammer behind the first or usual
sticker i, in order to act beneath the hammer nearer its centre of motion e.
The second sticker m is borne upwards beneath the hammer by the elastic
force of the wire spring o, which is, formed with a curled eye to give it
elasticity, and it is fastened beneath the intermediate lever g at the remote
end thereof, so as to act upwards beneath the foremost end of the additional
lever l'at n, and consequently beneath the lower end of the second sticker m,
so as to urge the same endways upwards beneath the hammer, in order
to counterpoise the weight of the hammer, as is clearly shewn in Figures 31,
32, and 33. The proportions and relations of the different members of the
improved action above described are such that, by allowing the front or touch
end 6 of the finger key to rise up or return merely one third of the full extent
of its previous motion downwards, the usual sticker i is allowed to replace
itself under the hammer as in Figure 33, the weight of the upper end of the
hammer being counterpoised by the elastic force of the spring o transmitted
upwards beneath the hammer by the second sticker m, as already explained.
With this improved action a performer on the upright pianoforte will be
enabled to command the hammer to the string as he may desire, as is the case
with Erard's grand pianoforte, whereof the refined touch is so much appre-
ciated by skilful performers by enabling them to increase or decrease the
sounds, according to the expression they wish to give to the music, whilst
with the common action usually applied in upright pianofortes a performer
can only command the hammer with the whole depth of touch or descending
motion of the finger keys, whether he has to express piano or forte.
The above improved action, see Sheets VI. and VII., combines the two pro-
perties requisite for effecting prompt and easy repetition of the same sound by
the touch of the finger key, namely, the spring o and second sticker m to
support the hammer, and the manner of causing the escape of the usual
sticker i from its hold beneath the hammer, when the latter strikes the wire
last, so that the sticker will regain its said hold beneath the hammer with but
a small ascent or return of the finger key.
Sheet VIII. represents another action for upright pianofortes, effecting the
requisite repetition action.in the touch by the application of the spring only.
The same letters of reference denote the same parts as in Sheets VI. and VII.,

page_text: and the writing on those parts, together with the foregoing description, will
assist to explain Sheet VIII., wherein Figure 35 represents the finger key
and the action in the resting position. Figure 36 represents the position
which the parts of the action assume after the touch end of the finger key has
been pressed down to its lowest position by the finger, and the upper end of
the usual sticker i has escaped from under the hammer which has already
struck the wire, and has then fallen upon the spring o, which spring supports
the hammer in such a position (as in Figure 36) that the upper end of the
sticker i will replace itself beneath the hammer again, as shewn in Figure 37,
by allowing a little rise of the front end or touch end of the key so as to
prepare the hammer for repeating the blow on the wire by pressing down that
front end of the key to its lowest position by the finger. v is a regulating
stop to limit the height to which the spring is allowed to bend upwards, in
respect to the sticker i. That stop vis fastened to the front side of the
sticker i by a screw passing through a slot in v, which admits of the requisite
regulation. The three positions represented in Sheet VIII. correspond to the
three positions represented in Sheets VI. and VII., namely, Figure 31, Sheet VI..
and Figure 35, Sheet VIII., are both representations of the several parts in
their resting positions when the front or touch end of the finger key is at its
highest position. Also, both Figure 32, Sheet VI., and Figure 36, Sheet VIII.,
represent the positions which the several parts assume when the said front end
of the finger key is pressed by the-finger down to its lowest position; and both
Figure 33, Sheet VII., and Figure 37, Sheet VIII., represent the positions
that the several parts will assume when the front end of the finger key has been
allowed to return, or rise up again a very little from its said lowest position,
so as to prepare for a. repetition of the blow.
Part the Fourth. New set of Pedal Keys applied to Grand Pianofortes for
Sounding certain Bass Notes by the Feet; see Sheets IX., X., and XI.-Great
musicians, and especially those who profess church or classical music, are
accustomed in organs to have a set of pedal keys to be pressed by the feet at
the same time that they are using their hands on the finger keys of the
instrument. It has been long wished to have such pedal keys applied to
grand pianofortes, and experiments have been made for that object. Having.
succeeded, after much labour, in making such an application in a more satis-
factory and efficient manner than has been done before, I claim the particular
mode herein-after described, by which such a set of pedal keys are applied to a
grand pianoforte, and which I offer as a great improvement upon the instrument,
as it will enable great masters of the art to perform the music already com-
posed by great composers, such as Sebastian Bark and others, for an instru-

page_text: ment with pedal keys, and it will further enable skilful performers on the
pianoforte to produce new and imposing effects, which cannot be produced by
grand pianofortes without the addition of such pedal keys.
Sheets IX., X., XI., represent my new set of pedal keys, applied to the
front end of an horizontal grand pianoforte of seven octaves, from note A to
note A. The set of pedals being applied to thirty-two of the bass notes,
namely, from the lowest note A, answering to note A, 32 feet in the organ, up
to the third note E above. The said thirty-two pedal keys, therefore, cor-
respond to and are duplications of thirty-two of the ordinary finger keys, for
that number of the lowest bass notes of the scale of the pianoforte, which finger
keys are retained just as usual throughout the extent of seven octaves, from
note A to note A. It is obvious that the extent or compass of the set of
pedal keys may be varied at pleasure, according to the extent of the scale of
the pianoforte, or to the wish of the performer. Sheet IX. is a longitudinal
vertical section of the front end of the grand pianoforte, showing the mode of
communication between the two pedal keys and the ordinary finger keys.
Sheet X. is a horizontal plan, and Sheet XI. a corresponding front elevation,
of the same front end of the grand pianoforte. The thirty-two pedal keys
are. disposed side by side in a row beneath the feet of the performer, as
appears in Sheet X., and they correspond to an equal number of the lowest
bass notes and finger keys of the scale of the pianoforte, the correspondence
of the pedals with the finger keys being marked in Sheet X. For instance,
the lowest note A in the base of the scale of the pianoforte is marked A on
the left-handmost pedal key in the row of pedal keys, and the corresponding
finger key is also marked A on the left hand of the ordinary row of finger
keys. In like manner the uppermost note to which a pedal key is applied is
marked E at the right-handmost end of the row of pedal keys, and the cor-
responding finger key is also marked E, being the thirty-second in the row of
finger keys, counting from the left-hand end of the row of finger keys of the
pianoforte. It is the last-mentioned pedal key and corresponding finger key
that are represented in the vertical section, Sheet IX., wherein a is the centre
of motion of the finger key; and at the remote end of the finger key a bended
wire b is screwed into the under side of the wood of the finger key, so as to
project downward therefrom, and form the point of communication between that
finger key and the corresponding pedal key, by the said wire b bearing upon the
upper end of the upright rod d, which rod is borne upwards by a connection at its
lower end with the backmost end of a lever arm e, see also Sheet X., which
arm projects out backwards from near the left-hand end of a horizontal axis f;
and from near the right-hand end of that axis f another lever arm g projects

page_text: out forwards, and the frontmost end of g is connected by an upright rod h with
the pedal key by a joint l, near to the backmost end thereof, the centre of
motion of the pedal key being at k. The bended wire b is represented full
size in two separate Figures in Sheet IX., in order to shew more clearly its
construction. It is tapped and screwed into the wood of the key, for the
purpose of regulating its projection downwards beneath the key, suitably for
effecting the requisite communication of motion to the upright rod d by.
downward pressure on the upper end thereof, without other connection with.
that end than by mere contact. The said upright rod d terminates at its
lower end with a screwed pin or piece of wire, which passes freely down.
through a hole at the backmost end of the lever arm e, that hole being bushed.
with cloth in order to avoid noise, and a leather nut is screwed on the screw,
of the upright rod d above the lever arm e, and another such nut below e.
The upper end of the upright rod terminates with such a screwed wire,
which is connected with the frontmost end of the lever arm g by two other.
leather nuts. Those (together with the aforesaid) leather nuts serve to adjust
and regulate the play of the different parts which are to transmit the requisite
motion from the pedal key to the finger key. The lower end of the upright
rod h is connected with the pedal key by means of a brass joint 1, screwed fast
into the wood of the pedal key, and forming a joint for the lower end of the
upright rod h, to cause it to descend with an endways downward motion
whenever the key is depressed by the foot. The pedal key is borne upwards.
by effort of a spiral spring m, which is placed beneath the pedal key, in order
to keep it up in contact with the stop screw s,. when at rest, as is shewn in
Sheet IX., which represents the resting position of the parts. The said
spring m yields easily when the pedal key is depressed by the foot, in order.
to cause the several parts above described to transmit the requisite motion to
the backmost end 6 of the corresponding finger key, so. as to raise up
that end by the upright rod d acting upwards beneath the bended wire b,
and thereby cause the hammer to strike the wires. of the corresponding
note, which is done by so raising up the backmost end b just the same as
would be done by depressing the front end of the same finger key by the
finger. The spring m raises up the pedal key as soon as the pressure
of the foot is removed therefrom, and restores all the parts to their resting
position, Sheet IX..
The foregoing description relates to the parts belonging to one pedal key, and,
its corresponding finger key, all which parts must be repeated as many times
as there are pedal keys in the set, in order to communicate in a similar manner
to what has been described with the corresponding finger keys of the pianoforte ;.

page_text: but note, the pedal keys are much further apart than the corresponding finger
keys, and therefore, in order to establish the requisite communication between
cach pedal key. and its corresponding finger key, the several horizontal axes f
are made of different lengths, that is to say, the distance along each axis f
between the place where the lever arm g projects out forward and the place
where the other lever arm e projects out backward from the saine axis f, is a
different distance in each of the several axes f, so as to suit the different
distances between the places where the several finger keys are situated in the
width of the pianoforte and the several places in that width where the corre-
sponding pedal keys were situated. The several horizontal axes f are dis-
posed one above another in the same vertical plane. All this is sufficiently
explained in the front elevation, Sheet XI., by tracing out the row of parallel
horizontal lines in red ink which represent the central lines of the several
horizontal axes f, and also represent the length of those axes. The two other
rows of parallel vertical lines in blue ink represent the central lines of the
several upright rods h in the front, and d at the back. The corresponding
musical notes which are marked in black ink on the several pedal keys
in Sheets X. and XI., and similarly marked in black ink on the corresponding
finger keys, and also similarly marked in Sheet XI., on the horizontal centre
lines of the several axes f and front upright rods h in red ink, and on the
centre lines of the back upright rods d in blue ink, will assist in so tracing
out the several connections. The upright rods h in the front are of different
lengths, and so are the upright rods d at the back, as is apparent in Sheet XI.,
but the length of any one upright rod h added to the length of its cor-
responding rod d is in all cases the same, namely, a length equal to the
difference of height between the row of finger keys and the row of pedal keys.
The several stop screws s serve for the adjustment of the quantity of motion
that each of the several pedal keys. should have in order to act properly on the
corresponding finger keys. t, t, are two properly shaped metal rods fixed
horizontally at a suitable height above the row of pedal keys, to allow the feet
to act thereon without interference from the rods t, t, which serve to rest the
feet upon whenever the performer may require.
In Sheets IX. and X., n and n represent the two usual pedals of grand
pianofortes, one such pedal on the right, which, when depressed (by the right
foot) raises the dampers, and the other pedal on the left, which, when
depressed (by the left foot) shifts the action, so as to remove the hammers
and cause them to strike only two or one wire for each of the notes in the
scale of the pianoforte. The said two pedals n and n differ from the usual
pedals in their shape and manner of being applied so as to avoid interference

page_text: with the row of my new set of pedal keys. The front end of each pedal n is
bended upwards at o, for the foot to act upon it, leaving space beneath each of
the ends o for the foot to act upon the pedal keys. The centre of motion of
each pedal n is at q, and the action of each pedal is transmitted up into the
pianoforte by the upright rod p, which rod is as usual in grand pianofortes.
The new set of pedal keys above described are contained (together with their
mechanism) in a convenient frame and case, which frame serves to replace
the two ordinary front legs of the grand pianoforte, for the two upright
standards of that frame stand nearly at the places of those two ordinary front
legs; and at the under side of the usual horizontal case of the grand pianoforte
two metal plates are fixed with screws, and holes in those plates serve as
sockets, which are fitted to receive two pins which project upwards from the
upper ends of the aforesaid upright standards of the frame when the piano-
forte is placed over those pins, and they will then ensure that each of the
upright rods & will come beneath the wire b at the backmost end of that finger
key beneath, with such upright rod d is to operate with upward motion when
the corresponding pedal key is pressed down with the foot as already explained.
The upper ends of the several upright rods d, d, must be so cut or regulated in
their height that they will range in a horizontal straight line when the pedal
keys are all in their resting position, as in Sheet IX., and the row of the
said upper ends of those upright rods d are all admitted up through a groove
conveniently cut out in the key bottom of the pianoforte for allowing the
said upper ends of the several rods d, d, to apply beneath the several bended
wires at the backmost ends of the finger keys with a very small space of
play between the said upper ends and the said wires. The foregoing
description and the Drawings explain how, by depressing any one of the pedal
keys with the foot, the corresponding finger key in the pianoforte is also
depressed, and made to strike the corresponding wire or wires by transmission
of the downward motion of the pedal key to produce a lifting up of the back-
most end of the finger key, and thereby produce the same effect as if the
front end of the key were depressed by the finger.
Additional note on Part the Second.-It has been therein stated, in
reference to Sheet V. respecting my apparatus for tuning by a distinct tuning
screw for each wire, that such apparatus may be applied either to my new
wrest plank of metal and wood, or upon my new wrest plank of metal only.
For more complete explanation of the latter application (to the wrest plank
of metal only) I have annexed Sheet XII. wherein Figure 38 is a front view
of my new metal framework adapted to an upright pianoforte, with vertical
wires as already described in Part the First in reference to Sheet IV., that

page_text: framework being composed of the hitch pin plate, the metallic bracing bars i,
and the wrest plank, which latter is entirely of metal, either of different
pieces of metal firmly united together by rivetting or otherwise, or else of one
piece of cast metal, which latter is shewn in Figure 38, and is preferable.
The said metal framework is almost entirely independant of the wood frame-
work of the instrument, being of adequate strength to sustain entirely by
itself the pull of the wires, which pull is no longer operative to strain the
wood employed in the general construction of the case of the instrument,
except as respects the bridge on the sounding board, which is put in vibration
when the wires are struck by the hammers.
Figure 39, Sheet XII., is a side elevation, and Figure 40 a front elevation
(drawn full size), of screw tuning apparatus to be applied to Figure 38, the
said screw tuning apparatus being similar to those herein-before described in
reference to Sheet V., and the same letters of reference are used for like parts
in both Sheets V. and XII., the screw tuning apparatus, as it is represented in
front in Figure 40, is for the wires of two notes of the scae. each apparatus
having three distinct tuning screws for the three wires belonging to the same
note (but the apparatus might be adapted for only two or one wires to each
note as already explained in reference to Sheet V.).
In Figures 39 and 40 the three screw tuning apparatuses for the three wires
belonging to the same note are represented with a triangular plate fixed by a
screw at each angle thereof. The musical sign of the note to which it belongs
is engraved upon the place.
In Figure 38 the letters z, z, indicate the places where the several screw
tuning apparatuses are applied and fastened on against the front surface of the
metal wrest plank, one such apparatus (containing three, two, or one tuning
screws) being so applied to each note throughout the whole scale in the
instrument. Figures 39 and 40 differ from the Figures in Sheet V., already
described, in the manner of attaching the end of the wire to the nut f of the
tuning screw h, the attachment being by means of a cross pin x, inserted into
a hole across the nut f, and passing through the eye of a loop formed at the
end of the wire by twisting, and secured from untwisting by soldering the
twist with fusible metal solder; the said loop of the wire is introduced into a
mortice hole cut in the nut f of the requisite size, to admit the said loop at
the end of the wire, and the pin x is inserted across the eye.
Sheet XIII., Figure 45* represents my new application of tuning screws
and of metal framework adapted to a grand pianoforte, that framework being
composed of the metal hitch pin plate, the metallic bracing bars, and the
wrest plank of metal only (either made of different pieces of metal united

page_text: together, or of one piece of cast metal, which latter is preferable), the said
framework being similar to the framework already described for upright
pianofortes in reference to Figure 38, Sheet XII., except that the framework,
Figure 45*, differs from Figure 38 in the circumstance that the cast metal
wrest plank part is provided with prominent brackets of metal, suitably formed
for supporting a horizontal metal bar, to which is fastened the wooden rail called
belly rail, whereon the belly or sounding board is glued; that horizontal metal
bar, together with the connecting brackets by which it is supported from and
connected with the metal wrest plank, form a firm framework bordering the
open space which is left for the hammers to pass up through from below, in
order to strike the wires, as is usual in grand pianofortes.
.
Figure 46 is a longitudinal vertical section of the metal work of the metal
wrest plank, shewing one of the connecting brackets between the same and
the aforesaid horizontal metal bar, which is for strengthening the wooden
belly rail whereon the sounding board is glued. The same vertical section,
Figure 46*, also shews the tuning screws h, as already described in reference
to Sheet XII. The letters z, in Figure 45", indicate the places on the metal
wrest plank for fastening the several screw tuning apparatuses in the
respective positions for each note throughout the whole scale of the instrument.
Additional note on Part the Third.-Figures 41 and 42, 43 and 44,
Sheet XII., represent modified constructions of the adaptation (herein-before
described in reference to Sheets VI., VII., and VIII. of Sebastian Erard's
repetition grand action to upright pianofortes. The second sticker, already
described in reference to Sheets VI. and VII. (see also Figures 41 and 42,
43 and 44, Sheet XII.), instead of being left free beneath the butt of the
hanmer near to its centre of motion e, as herein-before described, is in the
present modification to be connected to that butt with a joint pin. For this
purpose the second sticker may be formed as in Figures 41 and 42, with
a fork m at its uppermost end, that fork embracing the butt of the hammer,
and being connected therewith by the said joint pin. And the same second
sticker may have a similar fork at its lowermost end (as in Figures 41 and 42)
for connecting that lowermost end by a joint pin with the additional lever 1;
or the second sticker may be formed of wire bended at right angles into a
horizontal direction at its uppermost end, as shewn in Figures 43 and 44,
and that horizontal end inserted into a hole through the butt of the hammer,
to act as a joint pin, which it will do with exactly the same effect as the fork
and joint pin in Figures 41 and 42. Also the lowermost end of the same
second sticker may be connected with the additional lever 7 by a like mode,
as shewn, in Figures 43 and 44. Figures 41 and 44 are front views of the

page_text: aforesaid two differently constructed second stickers, but both are alike as to
having a nut at their midlength, which nut, being turned, will regulate their
length between the joints at their upper and lower ends with precision
suitably for their operation.
Figures 45 and 46, Sheet XII., explain a substitute for the regulating
stop herein-before described in reference to Figures 35, 36, and 37,
Sheet VIII., for limiting the height to which the spring o in those Figures
is allowed to bend upwards in respect to the sticker i. The sliding piece v
is fastened (as before described) to the front side of the sticker i by a screw
passing through a slot in v, which admits of the requisite regulation; but
instead of the stop v reaching up over the spring o, in order to regulate it
by stopping its motion upwards, the piece is provided with a silk string,
each end of which is fastened to the two uppermost corners of that piece v,
and the midlength of the same silk string being tied to an eye formed by a
curl in the wire of the spring the spring o can be regulated by adjusting the
sliding piece upon the sticker i in manner already described in reference to
Sheet VIII.; and the substitution of the silk string for the upper part of the
stop v of the former construction, Sheet VIII., has the same effect of limiting
or stopping the upward flexure of the spring with less impediment to its
freedom of motion, and consequent elasticity. The similar application of silk
strings may be made with advantage to other springs belonging to the action
of pianofortes. Such springs usually operate by bearing against and pushing
the part or member of the action on which they are to operate; but if such
a spring is connected by a silk string in the manner above described, so as to
transmit to the said part or member on which it is to operate the elastic force
of the spring by a pulling action, friction of the spring pushing against that
member will be avoided, and there will be no impediment to the freedom of
motion and consequent elasticity of the spring.
Figures 47 and 48, Sheet XII., represent a new centre of motion for the
hammers, which may be either be used in horizontal pianofortes (where cach
hammer has a separate centre of its own), or one of those improved centres to
each hammer may be applied to upright pianofortes (instead of the usual
centre plates commonly made in lengths containing the centres for the
hammers of several adjacent notes). The chief improvement in these new
centers is the application to each centre of a screw a, having two spiral
threads cut on different parts of its length, those parts being of different
diameters, one of those threads around the largest part of the screw (which
is nearest to its head) being a single-threaded helix, the thread around
the smallest part of the screw (which is farthest from the head) being a

page_text: double-threaded helix.
The single thread around the largest part of the
screw nearest its head works in the front thickness 6 of the centre, and
the double thread around the smallest part of the screw works in the back
thickness c of the centre. The centre b, c, is formed out of a solid piece of
brass of the requisite thickness to admit of a hole for the reception of the
centre pin being drilled edgeways into it. The brass is afterwards cut by
means of a mechanical saw in order to separate the front part 6 from the back
part c of the brass, so as to allow of their being separate and elastic pieces.
The brass centre being so made, the smaller double-threaded screw is inserted
through the front bar b into its socket or place in the back part c of the centre,
and the larger single-threaded screw comes into its socket or place in the front
part of the centre; and from the different rates of motion produced by the
different threads around the two parts of the screw (the rate being twice as
rapid in the double-threaded screw as in the single, it follows that by turning
the screw a to the right or to the left the two parts b and c of the joint will be
slightly closed or opened, and thereby grasping or releasing the ends of the
centre pin e, until an accurate fit is obtained without shake.
.
Having now described my said improvements in the construction of piano-
fortes, I, the said Pierre Erard, do hereby declare that the new Invention,
whereof the exclusive use is granted to me by the Letters Patent herein-before
recited, consists in the following particulars, namely,-
Firstly, the wrest plank herein-before described in Part the First hereof, in
reference to Sheet I. as applied to grand pianofortes, and in reference to
Sheet II. as applied to square pianofortes. Also in reference to Sheets III.
and IV. as applied to upright pianofortes with vertical wires and with oblique
wires, the novelty of such wrest plank being that its strength to resist the
pull of the wires is derived from metal, and the wood which is applied thereto
(if any wood is so applied) is only for the purpose of receiving the usual kind
of wrest pins or tuning pins in case such tuning pins are used. But the
wrest plank may be made entirely of metal, in cases when tuning screws,
according to the second particular, are preferred to be used (either for a part
or for the whole of the wires throughout the scale of the instrument) instead
of such wrest pins of the common kind. Also the metallic bracing herein-
before described in Part the First, in reference to Sheets III. and IV. with
metallic bars, two or more in number, as applied to upright pianofortes of any
description.
Secondly, the tuning screws herein-before described in Part the Second in
reference to Sheet V., with a distinct tuning screw for extending each wire.

page_text: Thirdly, the improvement herein-before described in Part the Third in
reference to Sheets VI., VII,, and VIII. (also in reference to Sheet XII.) of the
modifications in the construction of Sebastian Erard's repetition grand action,
which modifications render the same applicable to upright pianofortes.
Fourthly, the new pedal keys herein-before described in Part the Fourth in
reference to Sheets IX., X., and XI., as applied to a grand pianoforte, with
the mechanism there described for establishing the requisite communication
between each pedal key and its corresponding finger key.
Lastly, the improvement herein-before described in Part the First, also in
Part the Second, and particularly described in reference to Sheets XII. and
XIII. The improvement consisting in the combination described in reference
to the two last-mentioned Sheets of the wrest plank wholly of metal with the
tuning apparatus, having a distinct tuning screw for each wire, together with
the metallic bracing bars and metal hitch pin plate. The result or beneficial
effect of this last head of improvement being, that the pull of the wires of
the pianoforte is almost wholly sustained by the metallic framework without
any aid from the wood of the instrument, beyond so much as is necessary to
excite sonorous vibration in the wood bridge and sounding board. Sheet XII.
(which is an example for the construction of an upright pianoforte according to
this last improvement) and also Sheet XIII. (which is an example for
the construction of a grand pianoforte according to this last improvement)
are instruments peculiarly adapted for exportation to extreme climates
as to heat and humidity. It is by virtue of the application of the wrest
plank of metal only of the tuning screws (which are the second head
of improvement) that I am enabled to dispense with wood for resisting
the pull of the wires. But note, on account of the expence of a complete
series of distinct tuning screws for each wire throughout the whole scale of
the instrument, a short series of such distinct tuning screws may be applied to
the wrest plank of metal only for the several wires at the lower or bass part
of that scale. In which case as much wood must be applied to the metallic
wrest plank (and united thereto in the manner herein-before described in Part
the First) as will be sufficient to receive ordinary wrest pins or tuning pins for
the several wires of that upper part of the scale of the instrument, and such
partial adoption of the last improvement will be included therein.
In witness whereof, I, the said Pierre Erard, have hereunto set my
hand and seal, this Eleventh day of March, in the year of our Lord
One thousand eight hundred and fifty-one.
PIERRE (L.S.) ERARD.

page_text: AND BE IT REMEMBERED, that on the Eleventh day of March, in
theyear of our Lord 1851, the aforesaid Pierre Erard came before our said
Lady the Queen in Her 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 Statute made for that purpose.
Enrolled the Eleventh day of March, in the year of our Lord One
thousand eight hundred and fifty-one.