IM- PROVEMENTS IN PIANOFORTES
Year: 1862

page_text: LETTERS PATENT to George Henry Hulskamp, of Troy, State of New
York, in the United States of America, and of 53, Chancery Lane, in
the County of Middlesex, Pianoforte Maker, for the Invention of "IM-
PROVEMENTS IN PIANOFORTES
"
PROVISIONAL SPECIFICATION left by the said George Henry Hulskamp:
at the Office of the Commissioners of Patents, with his Petition, on the
28th June 1862.
I, GEORGE HENRY HULSKAMP, of Troy, State of New York, in the United
States of America, and of 53, Chancery Lane, in the County of Middlesex,
Pianoforte Maker, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PIANOFORTES," to be as follows:-
My Invention relates, first, to sounding boards of pianos; and consists, first,
in imparting a degree of tension to the sounding board in contradistinction to
the state of compression to which they are always reduced in pianos, by reason
of the tension of the strings exercising a compressing influence on the frame
or braces to which the sounding board is attached. The tension of the sounding
board, whether of wood, metal, or other material, may be given and maintained
in any suitable manner; but according to another part of my improvements I
place the sounding board on one side of the braces or frame and the strings on

page_text: the other, that is to say, the strings are above and the sounding boards below
the braces or distending timbers or frame. The tension of the strings so
disposed with relation to the sound board not only distends and produces
tension on the sounding board, but it also strengthens the bracings. The
bridges are supported from the sounding board by upright and diagonal sound-
ing parts. These parts are placed at suitable intervals throughout the length
of the bridges, or they may be replaced by a continuous board with openings
for the passages of the braces. In using posts, I prefer to make them thin in
the direction transversely to the strings, but of some extent lengthwise at the
base and tapering up to the bridge. By the application of diagonal posts or
struts, which I apply principally to the bridges of the covered or bass strings,
the vibrations are transmitted to the middle of the sounding board, and thus
distributed more uniformly than usual over its entire surface, and to these
bridges I apply both upright and diagonal sounding posts. In grand piano-
fortes, I prefer to dispense with the bent side in the frame and case, and
extend the sounding board over the increased area so obtained, so that the
curved bridge does not rest on the sounding board so near its edges as
usually.
The second part of my improvements relate to the hitch board, and consists
in making it of several thicknesses of wood combined, and having the grain
running in different directions, by which I am enabled to dispense with the
metal hitch plate used in the ordinary construction. This wooden hitch
plank or board I make to come close up to the bridge, and use with it a
sounding board extending no farther than the bridges or below the frame, as
herein-before described; or it may be with a sounding board above as well as
below the frame, which I sometimes adopt, but in all cases confine the upper
sounding board to the limits of the bridges. In straining the sounding board,
as described, I place a metal plate under the front part of the piano (under
the keys), from which the board is strained or placed in tension by suitable
screws and other parts. I connect this plate by metal ties with the lower ends
of upright cast-iron brackets receiving the strain (in horizontal pianos) of the
braces or distending bars or frame of the piano; the upper ends of these
brackets abut against a metal plate or facing of the wrest plank, which receives
the thrust and tension of the strings. The lower plate is connected with a
metal plate above the wrest plank by suitable bolts; at the upper part of the
frame (the treble), I carry up the facing plate of the wrest plank above the
strings, which pass through it in holes made therein, and which forms the bridge
or stop of the strings at this point; the holes, however, do not form the stop,
which is formed by a kind of hooked overhanging part of the metal, which

page_text: is made quite straight, and maintains the strings at a uniform level. It will be
evident that it would be difficult, if not impossible, to obtain this uniformity of
level and bearing of the strings by the holes alone, whereas it is easily and
properly effected by this means.
Another part of my Invention relates to a similar construction of the agrafes
or stops for the strings over the wrest plank. These stops are small plates of
metal standing up from the wrest plank, through which the strings pass, each
having three holes in grand pianos for the three unisons. When simply passing
through holes it is difficult to reduce them to a uniform level, so that the
hammer in striking gives the same impact to each unison; I therefore form
the agrafe or stud with an overhanging lip or piece, which is easily formed
straight, and which dips thè strings a little from the holes and maintains them
at the uniform level desired.
My improvements in the action of pianofortes are represented in the
Drawing annexed, which is a vertical section between the keys A, A. It
represents the several parts in their full size and proper proportions. The red
shaded parts are those that are covered with cloth, felt, or buckskin, to
prevent noise. A bar B extending lengthwise across the pianoforte is firmly
attached to the frame in the usual manuer. To this bar is screwed the
hinge butt C, and to the latter is attached the hammer butt D, with the
hammer E by the joint 1. Upon the key A, A, I attach a lever F by the
screws G and H, and to this lever is attached the jack or hammer lifter I, I,
by the joint 2. To the jack or hammer butt is attached by the joint 3 a
detacher, represented at J; this is pressed upwards by a spring N inserted into
the lever F, and bearing against a projection on the detacher until the
upward motion of the detacher is arrested by a stop K, attached to the
projection on J by a screw, whereby the length of K, may be readily adjusted.
To the detacher J is also attached a stem or screw L, upon which a round-
headed polished nut is screwed, its height can be adjusted by its screw in
order to bear against the point M of the hammer butt D for the object
hereafter stated. The wire spring N also serves to press the hammer lifter or
jack against the hammer butt D; O is the back check to prevent the rebound
of the hammer in the usual form. A wire spring P attached to the hinge
butt C, pressing against the piece of felt Y on the side of the hammer butt,
serves to support and regulate the weight of the hammer, a small slit is
made in the felt to receive the spring. The points M and x of the hammer
butt are at the same distance from the centre 1, and should be made to press
equally on the end of the jack and the end of the nut on L. But when the
hammer is raised by pressing on the key as the point M moves somewhat

page_text: .
backwards towards the jack as well as upwards, and the nut moves forwards
and upwards, they become disconnected by a small space, so that the point M
has a free motion towards the jack without touching, the same when the
hammer is raised; Q represents one of the strings. The operation is as
follows: When the back part of the key is raised by pressing down the front
.end, the hammer will be carried. rigidly upward. by the jack pressing against
the hammer until it has been brought to within three-eighths of an inch from
the strings, then the end of the detacher J strikes against the bar B, pushes the
jack out from under x, and becomes fully detached when the hammer has
been brought to within about one-eighth of an inch from the strings. After
the blow has been given the hammer will descend about half an inch, the
point M will then fall upon the nut on L, and the hammer will become
.connected with the head of the back check, which prevents the rebound
of the hammer. As the key descends the spring N presses the detacher J,
and. its stem L upwards under the hammer butt at M, by which the
hammer is slightly raised, the jack will then become again connected with
the hammer butt, so that the blow may be repeated with the small part only
of the motion of the key. The friction by detaching the jack from the
hammer butt has been a great defect in the actions at present in use. By my
construction, when the key is pressed down, the hammer rises to about three-
eighths of an inch from the string; the detacher J then strikes against the
bar B without friction, and the jack becomes detached with a very quick
motion, and this adds to the power of the blow. It is thus seen that the
stiffness common in other actions by detaching the jack is also here obviated
by the elastic detacher J, and this adds much to the lightness, power, and
durability of the action.
It is important in pianoforte actions to produce by the normal and but
slight movement of the keys the greatest power from the blow of the hammer,
combined with an easy, light, and elastic touch. To regulate the height of
the jack a screw H under the end of the lever F is inserted in the key, and
its rounded head extends up into a hole in the lever through which it is
regulated. An upright piece of wood S on the lever F serves for the other
bearing of the lever on the key. Another screw G passing about half way
through the lever serves to hold it to the key. Much difficulty has heretofore
been experienced by these levers getting loose and rattling from the effects of
heat, and the shrinking and swelling of the wood. Another mode of attaching
it is represented at U and V, it will there be apparent that any shrinking or
swelling of the wood will be compensated and all looseness prevented. The
upright piece of wood W on the hinge butt is for the same purpose as the

page_text: piece S on the lever P. A spiral spring I attached to the jack T and the
detacher J, as shown in the Drawing, will be found more convenient in small
pianoforte actions than the spring N of lever F.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Henry Hulskamp in the Great Seal Patent Office
on the 27th December 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HENRY HULSKAMP, of Troy, State of New York, in the United States of
America, and of 53, Chancery Lane, in the County of Middlesex, Pianoforte
Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of June, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Henry Hulskamp, Her special licence, that I, the said
George Henry Hulskamp, my executors, administrators, and assigns, or such.
others as I, the said George Henry Hulskamp, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN PIANOFORTES," upon the condition (amongst
others) that I, the said George Henry Hulskamp, my executors or adminis-.
trators, by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Henry Hulskamp, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Sheet of Drawings hereunto
annexed, and to the letters and figures marked thereon, that is to say:-
Fig. 1 is a longitudinal plan of the instrument as seen by a person above.
looking down upon the parts represented; Fig. 2 is a similar view of the
under side of the instrument.
It is supposed to be turned bottom side

page_text: upwards to show the sounding board on the under side. Fig. 3 is a vertical
plan as seen from the right-hand side of the instrument; Fig. 4 is an upright
view of one of the agrafes in full size. My principal improvement is designed
to affect the vibrations and tone of the sounding board. In the ordinary
construction of pianofortes of different kinds, the tension of the strings,
amounting to about thirteen thousand pounds, tends to produce a slight
curvature of the frame to which they are attached, and causes great com-
pression of the sounding board, and consequently injury to the tone of the
instrument. To remedy this defect, strong iron bars are usually placed
immediately above the strings in grand pianofortes, and to some extent
in square ones, and connected with the frame so as to prevent, as far as
practicable, its flexure and produce solidity. It is well known that some
degree of tension of a sonorous body materially affects its vibrations. The
head of a drum or strings of an instrument would produce little or no sound
without some strain upon them. So, too, in pianofortes, I have found that
some degree of tension in the sounding board produces a striking effect upon
the quality and volume of its tone, and the best effects are produced when
some relation exists between the tension of the strings and the strain upon
the board. My improvements consist in applying this principle to piano-
fortes of different kinds. I can dispense entirely with the cross bars before
referred to with the ordinary braces, but I prefer for more expensive or
grand pianos to cover the wrest and bitch planks with a thin solid metal
frame. The strain of the strings on one side of the frame is counteracted by
an unequal strain of the sounding board on the other. An equilibrium is
maintained between the two. Any excess or variation of the tension on one
side is in a measure communicated to the other, and a proper relation between
the two sustained. Fig. 1 shows the application of the principle to a grand
pianoforte. It is a view from above looking down upon the parts of the
instrument represented; A, A, A, A, A, A, A, is the ordinary wooden frame,
with its cross beams B, B, and C; on the frame is secured the hitch plate
D, D, D, D, to which the strings are attached in the usual manner. The
red lines represent the strings extending from the hitch plate to the wrest
plank E, E, E. In Fig. 3 the pianoforte is supposed to be turned bottom
side upwards to exhibit the sounding board S on its under side and its
attachments. The back end of it and the part of one of the sides are glued
to the frame and fastened by the pieces F, F, F, and screws as represented.
These fastenings are directly opposite to the fastenings of the hitch plate in
the
upper
side of the frame. The front end of the sounding board is made.
thick by glueing on two wooden cross bars, one on each side, and into these

page_text: are placed and fixed the iron screw nuts G, G, G, G, G, to receive the iron
bolts, which, passing through the fixed iron plates H, H, with screws on their
ends, serve to tighten and strain the sounding board. These bolts lie and act
in a direction parallel to the strings on the opposite side of the frame, and
should be tightened sufficiently to counteract the tension of the strings.
These bolts and screws are not, perhaps, indispensable, for if the end of the
sounding board on which they act were drawn tight and permanently fixed
before the strings were strained, the tuning of the instrument would of itself.
give a considerable degree of tension to the sounding board and partially
effect the object of my improvement. But the bolts and screws will be found:
to be highly advantageous to regulate and adjust the tension to the degree
found best on trial and use. These parts are also represented in the vertical
plan, Fig. 3. One of the long strings are shown extending from the wrest
plank at E and attached to the hitch plate at D directly opposite to it; on:
the under side the sounding board is attached at E and extends to G, and is
strained by the screw bolt at H equally with the tension of the strings at E.
To give strength and solidity to the structure, I attach to the wrest plank the
cast-iron plate I, I, which extends across the front part of the pianoforte.
Immediately under it on the bottom side of the pianoforte is a cast-iron plate
H, H, and the two are firmly held together by bolts passing through the
ends and the woodwork at J, J, and secured by nuts screwed on to the lower
ends. From the lower plate cast-iron braces T, T, T, T, seen in Figs. 2
and 3, extend and meet the upright cast-iron brackets K, K, K, K. The upper-
ends of these brackets bear against another cast-iron plate L, L, attached to
the back part of the wrest plank; a part of this iron plate is made to extend
up and constitute a bridge for the short string holes, being drilled through it'
for their passage, as represented in Fig. 3. The sounding-board bridges are
represented at N, N, for the covered strings, and O, O, for the uncovered ones.
From these the vibrations are transmitted to the sounding board by sounding
posts or braces. In pianofortes heretofore constructed the sounding board
bridges or the posts that have supported them have been made perpendicular
to the strings and the sounding board, and have thus imparted the vibrations
of the longer strings to the board near its edge where it is fastened to the
frame. I have found a greatly increased and improved effect by making the
communications with the sounding board near its middle and at some distance
from the line where it is attached to the frame. In Fig. 2 the dotted lines
Q, Q, P, P, and R, R, show the places on the inner side of the sounding-
board, where, after many experiments, I have placed the connections. Along
these lines a bridge about an inch in height is glued to the sounding. board.

page_text: At the places indicated by the cross lines, screw heads, pillars, or braces, some
of them perpendicular and some oblique, extend to the upper bridges that
support the strings. The bridge N, N, for the covered strings has two sets
of pillars or braces, one extending from N to P, and another from N to R,
as shown in Fig. 3. The end of the other bridge furthest back at Ois
connected with P by the diagonal brace or pillar O, P, as seen in Figs. 1 and
3. The other pillars of that bridge are perpendicular; one of them is
represented at O, Q, Fig. 3. Instead of pillars or braces to convey the
vibrations to the sounding board as described, there may be used instead one
continuous bridge extending from the strings to the sounding board, with
orifices for the beams B, B, and so curved that those pillars or braces should
be continued in it. This was my first plan and arrangement.
Fig. 1 represents the outline of a very small sounding board; on the upper
side of the frame it is attached to the frame A, A, and extends to the bridge,
N, N; this might be to cover the whole upper surface of the frame, like
the ordinary sounding boards; but I have not yet found it of sufficient advan-.
tage to compensate for the increased expense thereby occasioned. Some,
perhaps, would prefer to omit the upper sounding board altogether, but when.
used I make it extend no further back than the bridges, and this enables me
to make the hitch plate of several pieces of wood glued together, with the
grain or fibres running in different directions, and make it extend nearly to
the bridge, and thus making it hold the strings with sufficient firmness without
the use of the iron plate found in the ordinary construction. The bridge L,.
as well as the agrafes W, W, seen in full size in Fig. 4, I have constructed in
a peculiar manner. They have been made, heretofore, by simply drilling
holes through them, one for each string. The strings bear against the upper
sides of the holes, and produce a jingling sound on being struck by the.
hammer; to obviate which it has been customary to. insert pieces of cloth:
between the strings and their bearing places on the bridges. I have removed
the difficulty by making the top of the bridge curve over, as represented in
the Drawings, and securing to it a wire of soft metal to receive the whole
bearing of the strings. The holes are so drilled. that their centre corresponds:
with the under surface of the soft wire, and large enough to receive the.
three strings of each note without touching each other on the sides of the
orifice. The agrafe being made of soft mètal requires no wire to be inserted,
but the top is curved over, as shown at Fig. 4,.until its lower surface is on.
a level nearly with the centres of the holes, and receives the whole, bearing of
the strings.
Figs. 5 and 6 show modifications, in the construction of the agrafes, Fig. 5,

page_text: showing an agrafe formed with the bearing or stop of the strings formed on
each side, so that in fixing in position it may be adjusted with either side
towards the scale of the instrument, by which means it may be adjusted to
half turn, as in ordinary, instead of requiring a whole turn, as in that
shown at Fig. 4. The bearing surface of the strings being formed below the
holes through which they pass by interposing pieces of wire 1, 2, as seen,
which may be soldered to the body of metal of the agrafe.
Fig. 6 shows another modification equally advantageous with the latter
arrangement, as it may be adjusted, to half a turn. The bearing of the string
is formed by a piece of wire 3 introduced in a longitudinal hole, below which
the transverse string holes traverse. In these agrafes one hole is made for
cach wire. Although I have represented my improvements as applied to grand
pianofortes, yet it is manifest that they are equally applicable to any other.
form of the instrument by changes of form merely, which will readily occur
to any manufacturer.
My improvements in the pianoforte action are represented in Figs. 7, 8, 9,
.10, and 11 of the annexed Drawings, which are vertical sections throughout
the length of one of the keys A, A. The several parts are represented of their
full size and proper proportions. The red shaded parts are those that are
covered with cloth, felt, or buckskin to prevent noise; the blue shaded parts are
screws, metal wires, &c. A bar B extending lengthwise across the pianoforte
is firmly attached to the frame in the usual manner. To this bar is screwed
the hinge butt C, and to the latter is attached the hammer butt D, with the
hammer E, by the joint 1. Upon the key A, A, I attach a lever F by the
screws G and H, and to this lever is attached the jack or hammer lifter I, I,
by the joint 2. To the jack or hammer lifter is attached by the joint 3 a
detacher, represented at J. This is pressed upwards by a spring N inserted
into the lever Fin Fig. 11, and bearing against a projection on the detacher
until the upward motion of the detacher is arrested by a stop K attached to
the projection on J by a screw in Figs. 8 and 9; whereby the length of K may
be readily adjusted. It may be found more convenient to insert the stop K,
with its screw, into the bar B, as shown in Fig. 9 and also in Fig. 10, by B',
which is an action for upright pianos, herein-after mentioned. To the
detacher J is attached a stem or screw L, and which, supported by its spring,
presses with its polished head under the point M on the hammer butt D.; its
height can be adjusted by its screw in order to bear against the point M, for
the object herein-after stated. The wire spring N also serves to press the
hammer lifter or jack against the hammer butt D in Figs, 8, 9, and 10; the
spring N is inserted in a projection on the jack I, I; O is the back check.to

page_text: prevent the rebound of the hammer in the usual manner. A wire spring P
attached to hinge butt C in Fig. 7, pressing against a piece of felt Y glued
on to the side of the hammer butt, serves to support and to regulate the
weight of the hammer. A little cut is made in the felt to receive the spring.
The points M and X of the hammer butt are at same. distance from the
centre 1, and should be made to press equally on the end of the jack and the
head of the stem L. In grand pianos I make the point M a little further
than the point X from the centre 1. The upright action, Fig. 10, is in its
principal construction the same as in Figs. 7, 8, and 9; the hammer and its
butt is turned towards the front of the keys; in the butt there is a round hole,
which is substituted for the point m, and receives the head of the elastic
stem L, while the back check o, prevents the rebound of the hammer lifter.
In Figs. 8, 9, and 10, the stem L passes through the elastic lever J, and in
Fig. 9 also through the hammer lifter I, I; soft cloth is secured on the stem L
to prevent rattling in the holes of the jack and lever through which it
passes. In upright pianos of high construction and with great length of string
I use the arrangement shown in Fig. 11, in which the joint 4 is to be
connected with the joint 2 in Fig. 10, instead of using the lever F, its height
being arranged and adjusted by the length of the wooden stem 6 and screw 7.
The operation is as follows:-When the back part of the key is raised by
pressing down the front of it, the hammer will be carried rigidly upward by
the jack pressing against the hammer butt until it has been brought to within
three-eighths of an inch from the strings. Then the end of the detacher J
strikes against the bar B, the head of the stem L becomes disconnected by a
small space with the point M, and the jack is pushed out from under X, and
becomes fully detached when the hammer has been brought to within one-
eighth of an inch from the strings. It will be seen in Figs. 8 and 9, when
the end of the detacher strikes against the bar B, Fig. 8, or against the stop K,
Fig. 9, the head of the stem or screw L presses also under the hammer butt
by the point M¹ nearer to the joint 1; the stem L with its spring has a force
sufficient to raise the hammer when acting upon the hammer butt by point M,
but enough to sustain only about two-thirds of its weight when acting against
the hammer butt by point M nearer to the joint 1, and permits the hammer,
which has been disconnected with stem by M, to drop a little below the
strings. After the blow has been given the hammer will descend about half
an.inch, the point M will then fall upon the head on rod L, and the hammer
will become connected with the head of the back check, which prevents the
rebound of the hammer. As the key descends the spring N presses the
detacher I and its stem L upwards under the hammer butt at M, by which

page_text: the hammer is slightly raised, the jack will connect again with the hammer
butt, so that the blow may be repeated with a small part only of the motion
of the key. The friction, by detaching the jack from the hammer butt, has
been a great defect in the actions at present in use. By my construction,
when the key is pressed down the hammer rises to about three-eighths of an
inch from the string, then the detacher J strikes against the bar B without
friction, and the jack becomes detached with a very quick motion, and this
adds to the power of the blow. It is seen that the stiffness common in other
actions, by detaching the jack, is also here obviated by the elastic detacher J,
and this adds much to the lightness, power, and durability of the action. It
is important in pianoforte actions to produce by the normal and only small
amount of movement of the keys the greatest power to the blow of the
hammer, combined with an easy, light, and elastic touch. To regulate the
height of the jack a screw H, under the end of the lever F, is inserted in
the keys, and its rounded head extends up into a hole in the lever, through
which it is regulated. An upright piece of wood S, glued on to the lever I',.
serves for the other bearing of the lever on the key. Another screw G let
down about half way into the lever holds it to the key.
heretofore been experienced by this lever getting loose and rattling from the
effects of heat, and the shrinking and swelling of the wood, and the object of
this mode of attaching is to remedy that difficulty. Another mode of attaching
it is represented at U and V, and it is apparent that any shrinking or swelling
of the wood will be compensated, and any looseness prevented. The upright
piece of wood W in the hinge butt is for the same purpose as the piece S in
the lever F. A spiral spring T attached to the jack I, and the detacher J,
as shown in the Drawings, will be found. more convenient in actions for small
pianos than the spring N attached to the lever F.
Much difficulty has
Having described the nature of my Invention, and the manner of perform-
ing the same, I declare that what I claim as my Invention to be protected by
the herein-before in part recited Letters Patent is,―
First, the use of improved strained sounding boards in pianofortes, whether
made of wood, metal, or other material, fitted and strained in the manner
herein-before described, and when made to counteract the tension of the
strings, substantially as described.
Secondly, I claim the oblique sounding posts or braces on the continuous
curved sounding bridge or board, wherely the vibrations of the strings are
transmitted to near the middle part of the sounding board, substantially as
described.
Thirdly, I claim the extension of a wooden hitch board made thick with
'

page_text: different pieces of wood, as described, nearly to the sounding board bridge in
combination either with a sounding board above the frame extending no
farther than the sounding board bridge, or a sounding board below the frame,
or both, for the uses and purposes set forth.
Fourthly, I claim the mode set forth of strengthening the pianoforte by
making the iron brackets K, K, K, K, bear not only against the iron plate on
the upper side, but also against an iron plate through intermediate bars on
the under side, and connecting that iron plate with the top plate by the iron
bolts J, J, substantially as described.
Fifthly, I claim the construction of the bridge L and the agrafes, Figs. 4,
5, & 6, substantially as described, or making the bridge L of soft metal, in
the manner of the agrafes.
Sixthly, I claim the arrangement and construction of the actions for piano-
fortes, substantially as set forth above.
Seventhly, I claim the form and peculiar construction of the hammer
butts D, of the jacks I, and of the elastic detachers J, J, and their elastic
stems L, substantially as described, or their equivalents.
Eighthly, I claim the peculiar mode of attaching the levers, hinge butts,
&c., substantially as described, for the purpose of preventing looseness, and
the effects of shrinking and swelling.
In witness whereof, I, the said George Henry Hulskamp, have here-
unto set my hand and seal, this Twenty-sixth day of December, in
the year of our Lord One thousand eight hundred and sixty-two.'
Witness,
W. CLARK,
Patent Agent,
53, Chancery Lane,
London.
G. H. HULSKAMP. (L.S.)