A MODE OR MODES OF PRODUCING MUSICAL SOUNDS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, URELI
CORELLI HILL, Professor of Music, of New York, and a Citizen of the United
States of America, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-eighth day of June, One thousand eight hundred
and forty-seven, in the eleventh year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said Ureli Corelli Hill, my exors,
admiors, and assigns, Her especial licence, full power, sole privilege and
authority, that I, the said Ureli Corelli Hill, my exors, admors, and assigns,
and such others as I, the said Ureli Corelli Hill, my exors, admors, or assigns,
should at any time agree with, and no others, from time to time and at all
times thereafter during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within that part of Her said
Majesty's United Kingdom of Great Britain and Ireland called England, Her
Dominion of Wales, and Town of Berwick-upon-Tweed, in the Islands of
Jersey, Guernsey, Alderney, Sark, and Man, and also in all Her Majesty's
Colonies and Plantations abroad, my Invention of "A MODE OR MODES OF
PRODUCING MUSICAL SOUNDS;" in which said Letters Patent is contained a
proviso obliging me, the said Ureli Corelli Hill, to particularly describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, by an instrument in writing under my hand and seal, and to
cause the same to be enrolled in Her said Majesty's High Court of Chancery

page_text: within six calendar months next and immediately after the date of the said
in part recited Letters Patent, as in and by the same, reference being thereto
had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Ureli Corelli Hill, do hereby declare the nature of my said Invention, and
the manner in which the same is to be carried into practical effect, to be as
the same are described and ascertained in and by the following statement
thereof, reference being had to the Illustrative Drawings hereunto annexed,
and to the figures and letters marked thereon respectively, that is to say:-
My Invention of "A Mode or Modes of producing Musical Sounds'
consists,―
Firstly, in forks like the ordinary tuning fork, vibrating over apertures or
mouths in chambers of air.
Secondly, in springs, which are wires bent and fastened at one end to a
conductor or rack vibrating on a sounding board, and in the use of the
forks in the extreme upper part of the scale of the instrument in question,
that is to say, above the sixth octave, which may, by their peculiar form and
delicate manner of holding them, be used without the chambers of air or with
them. The forks are used in the treble, middle, and part of the bass; the
springs complete the lower part of the scale. Keys and action nearly as those
of the upright pianoforte are used to set these forks and springs in vibration,
or the construction may be suited to the horizontal action. I shall in this
Specification and Drawings only describe the instrument in the upright form.
The horizontal form would require the hammers to strike from above or below
at pleasure, and require the sounding board or boards in the back of the
instrument instead of under the instrument, as in the present description. If
an octave above a pitch C tuning fork vibrate over a person's mouth while
open to a certain capacity, a strong tone will be given, and as the mouth is
opened to more or closed to less than that given capacity, the tone of said fork
will impair, for the capacity of the mouth would thus become too small or too
large for the said fork, though not for a higher or lower note than C; the
larger capacity would require a lower fork, and the smaller capacity a higher
fork. The compass may with perfect ease be carried down five notes lower
than herein-after described, also several notes higher, I believe; but the
compass of notes here given in the upper part of the scale are probably more
than will ever be required. The two lower octaves, or twenty-five notes, or
two octaves inclusive, will be made with springs, and the next seventy-two
semitones, or one semitone less than six octaves, with forks, most or the
whole of them over the air chambers. The springs might be carried at least

page_text: opening of the back scale of the keys may be carried down for more than two
octaves lower, or as low or lower than forks can be practically agitated by the
touch.
DESCRIPTION OF THE DRAWINGS, SHEETS Nos. 1 and 2.
Sheet No. 1.-The Figure 1 represents the front elevation of the instru-
ment. Figure 2 represents the end elevation, with one side removed, exhi-
biting the side view of a chamber, a spring, and a fork, with the mode of
fastening or screwing the same to a section of the spring rack and fork rail;
side view of one of the supports for holding the stack of chambers perma-
nently over the table damper; damper wire; section of the action, with the key
and some of the hammers, and of the key which raises the damper, and
where the damper wire comes in contact with it when struck; and side view of
the cross piece, which the rack may be fastened to by the shank of said rack
at one point. Figure 3 represents the plan or top view, shewing the sounding
board, cross pieces in bottom of case, &c., &c. Figure 5 represents a side
view of a chamber, fork, damper, wire, hammer, key, and the stopper under
the chamber, and a double row of screws for holding the forks in the fork rail.
Figure 6 represents the bottom of the chambers, shewing the holes which the
stopper closes when the key is struck. Figure 18 is a scale of the number of
octaves contained in the musical instrument herein described, by reference to
which the locality or position of any note in the scale of this instrument can
be ascertained, which may be spoken of herein-after.
Sheet No. 2, Figure 4, represents in a side view a chamber damper, damper
wire, spring, fork, and hammer; in the latter the wooden part is pointed as used
for the forks, and one of the supports for the stack which is to rest on the
table, the cross piece to which the spring rack may be fastened at one point;
a section of the lower damper, rail for keeping the damper wires over the ends
of the keys, the upper end of said damper wires going through a slight
projection on the upper part of the chambers immediately over the mouths,
which, when all united in the stack, serve as an upper damper rail for the
forks. Figure 4* represents the form of the peg, which, by being glued across
in the inside of the chambers, is used to give strength and more solidity to the
Jower chambers. Figure 7 shews the mouths in the front view of the stack of
chambers in one form, one kind of fork rail, with double row of screws for
holding fast the forks, the props to support the stack, and the side view of the
able on which the props may be attached. Figure 8 shews the whole front
view of the springs, spring rack, fork rail, forks, damper heads, damper wires,

page_text: props or supports, and a side view of the table on which all that is connected
with the forks are supported; single screw for fastening fork to fork rail; whole
length of the lower damper rail for the forks for keeping the damper wires
over the ends of the respective keys; the frame, with small cross pieces near
the tops of the springs, and same lower down, serving as an upper and lower
damper rail for the damper wires to the springs to pass through, that they
may be in a line above the back ends of the respective keys opposite the
springs. Figure 9 shews the side view and manner of fastening a fork to a
section of the fork rail, with two screws for regulating the position of said
fork, which will be sufficient to shew how all the others may be secured and
fastened, with the exception of the upper octaves, where but one screw if
any would be required. Figure 10 shews a back view of the springs and
chambers, the frame for the spring damper wires same as in Figure 8,
the under damper rails same as in Figure 8; the cross piece which may be
used for putting a screw or pin through or in the crotch (or lowest angle) of
the shank of the spring-rack as an additional fastening in connection with the
rods (seen in Figure 11), going from the ends of it. Figure 11 shews a top
view of the same, and fastening of the spring rack. Figure 12 shews a top
view of one sort of fork rail. Figure 13 shews the top view of the fork rail
shewn in Figure 7. Figure 14 shews the side of a spring about the form for
low F, damper, damper wire, hammer, and a section of the spring rack, and
manner of fastening the springs with a screw to it. Figure 15 represents
different forms of springs. Figures 16 and 17, different spring racks, with the
cross pieces for the fastenings of their shanks. Similar letters of reference are
placed upon and denote corresponding parts, in so far as such parts appear or
can be seen at each of the Figures respectively. Most of the above Figures
will be more fully understood by the references to them in the progress of the
descriptions of the different parts of the instrument herein-after contained.
Firstly, chambers, see Sheet No. 2, Figure 4; Sheet No. 1, Figures
2, 5, and 6. The chambers are of two kinds, namely, the open and the closed.
To produce the same given note of same shape and material, an open chamber
must be twice the size of a closed one. In the open, the vibrations pass
through; in the closed, the vibrations return through the mouths or apertures
The materials of which the chambers may be made are various; wood, hard
or soft metal, and glass, I find to produce the tones perfectly well. If o
metal, zinc or tin is probably the best, as it takes less room; but if or wood
cherry, or any hard wood, or soft wood, as pine, spruce, or deal, &c., all wel
seasoned, and varnished inside and out, is the cheapest and easiest made, and
are perfectly good. They must be most thoroughly fastened and glued, so as t

page_text: be perfectly air-tight. I find that to give a precise size of a chamber is almost
useless, as when the chambers, particularly the sides of them, are of different
thicknesses of material, they must be of different sizes, more particularly in
the lower notes, beginning at the F in the third octave. See Sheet No. 1,
Figure 18. In the fourth octave and upwards, it is not of near so much
consequence. Thin material of, say, an eighth or three sixteenths of an inch
thick, will answer for the F, third octave, see Sheet No. 1, Figure 18, and
upwards, provided there be a peg, say three eighths of an inch diameter,
inside the chamber, directly through the middle of the chamber, with shoulders
at each end of the peg, so that they rest firmly against the inside of the sides
of the chambers to be glued and wedged, and glued at both sides, so as to
make the sides of the chambers quite solid. See Sheet No. 2, Figures 4, 4*,
Sheet No. 1, Figure 5, Letter O. Thus this mode will admit of thinner
material, and the sides become solid; this mode is not required higher than the
fourth octave; the stiffening may certainly be discontinued in about this part
of the scale, as the sides being so much smaller that the resistance is vastly
greater; also owing to the greater acuteness of the sounds, the difficulty almost
ceases, so that if made of wood, one eighth of an inch thick is quite sufficient.
Further, bars may be used as a substitute for the peg or post (though I
prefer the peg or post), say a quarter of an inch or less in thickness inside the
chambers to stiffen them. If some method similar to those described is not
used, the sides would require to be, I think, a full quarter of an inch in the
Jower notes; and as thick sides consume so much room or space, it is
desirable to dispense with them, if practicable. The mouths in the chambers;
see Sheet No. 2, Figures 7 and 4, and Sheet No. 1, Figure 5, Letter A, may
be about half the length, and of the width of the prongs (see Sheet No. 2,
Figures 4, 8, and 9, Sheet No. 1, Figures 2 and 5, Letter B) of the forks (see
as before) corresponding to them. Or if two are over the same mouth, it
should be about the width of the two. See Sheet 2, Figures 7 and 8, Letter C.
It will be seen from the above remarks, that thin wood (like veneer, &c.) or
thin lead, or common tin, without stiffening, will only do well for the smaller
chambers; the larger or lower chambers want thicker or stiffer material for
the sides. The thickness of the rims of the chambers may be such as best
suits the convenience of manufacture, provided it be one eighth of an inch
thicker if made of wood. In this instrument, for compactness and facility, I
use chambers narrow and rather square or oblong, unless in upper notes,
where holes cut or bored through solid wood are simple and satisfactory.
These chambers, when all glued and put together, I denominate a stack. See
Sheet 2, Figures 7, 10, and 11, Letter D. In this stack, the right side of a

page_text: Metal would
The mouths,
same width
If
chamber will do for the left-hand side of the chamber above. The large end
of the stack contains the lower chambers, and the small end the upper
chambers, the sides containing the mouths being in a line on the top, and
presenting a range longer in the bass and shorter in the treble. See Sheet
No. 2, Figure 7. In making a stack of chambers it is perhaps best to
commence with the lowest or largest one, and extend to the right or smaller
ones, until they are all glued together, if made of wood..
require other means of fastening together, soldering perhaps.
see Sheet No. 2, Figure 7, &c., need not of necessity be of the
or length, as shewn in the Drawings; a mouth narrow lowers the tone of the
chamber, while an open one raises it. The nearer the prong of the fork to
the chamber or cell the flatter the chamber becomes. I think they should in
I find that two forks a semi-
all cases be as wide as the prongs of the forks.
tone apart will do over or before one chamber, by having the chamber of a
tone or sound between two adjoining semitones; six chambers will be sufficient
for the octave. By this method the whole stack from the lowest to the
highest note will come into the width of the ordinary pianoforte action.
single chambers, or one to a note, is preferred (which is perfectly practicable),
in order to obtain the strongest tone in the lower chambers from the first F#
upwards, six or eight notes in the third octave, it will be best to give about
three fourths of an inch in width to each note, which would require an
extension of the back scale of the keys of some three or four inches. After
these few notes there is abundance of width, as half an inch to the note is
quite enough to the top of the scale of the instrument. The shank (see
Sheet 2, Figures 8, 16, and 17, Letter E) of the rack resting on the sounding
board must be turned towards the stack to bring it nearer the middle of the
sounding board. I have adopted in the present plan one chamber to two
notes until the sixth octave above, for the higher notes one note to a chamber
see Sheet No. 2, Figure 8, Letter F, and in the higher ones open in the backs,
see Sheet No. 2, Figure 10, back view of all the chambers and springs,
Letter G. In using two forks of adjoining semitones to one chamber it can
be tuned to the lower note of the two forks, then bore a hole under and
near the front of the chamber, near to and above the end of the key,
corresponding with the lower note (Sheet No. 1, Figure 6, Letter P),
which hole is to be increased or decreased in size till the chamber be made
in tune with the upper note of the two, which hole will be closed when the
lower key (see Sheet No. 1, Figure 5, Letter C*) is struck, and thus the
chamber be made in tune for the lower note. This fixture is called the
stopper (see Sheet No. 1, Figure 5, Letter Q), and is only required for

page_text: a few of the lower chambers, say four to six of them. The size of the
chambers may be ascertained in the following manner :-Have a given number
of forks made and precisely tuned, then take the width of the back part of
the keys and hammers you would use, and if you use two forks to one chamber
have them made of different dimensions, say some varying from eight by
twelve inches for the largest, and gradually decreasing in the same ratio, that
is, in height and depth, and all of the width of two back keys of your scale,
you will find the sizes for the lower forks commencing at the F #third octave,
which notes are much more difficult to arrive at than those even an octave
higher; but by trial the proper scale or size of the chambers will be found.
For the Proportions of the Chambers one to the other.-Organ pipes will
form correct data in making calculations for the areas which each chamber
should contain. Each prong of the fork may vibrate a column of air by
putting on the front prong a thin wire (or a very thin continuation of the.
prong may be forged) above and out of the end of said prong, with a thin
piece of tin or metal on the end of the wire, for a cell or chamber above the
lower range or stack. This upper stack must be over the dampers. A.
similar plan might operate on the springs if required.
For Tuning the Chambers.-If a chamber be too large for a note it may be
raised by boring holes into the rim. I prefer for this purpose to have the
holes opposite the mouths, or the back may be cut down until the chamber is
raised to the pitch desired. They may also be raised by moveable backs,.
which, by pushing them in nearer the mouths, the chambers become smaller,
and thus raise the tones of the chambers, and when in the right place exactly.
they may then be glued fast in. Chambers of same area inside, and made of
different thicknesses of material, will not give the same note. To find the
pitch of a chamber blow in the mouth of it, and it will give the note that.
belongs to it, or by striking on the side of it you will be assisted in finding
the note; thus it will be seen that by holes in the rim (better in the back
rim) the chamber is raised in pitch, or by thinning the sides it may be lowered.
The mouth of the chamber may be carried through a short projection or sort
of neck to receive the prong of the fork, if desired. The fork should be quite
close to the mouth of the chamber, or mouth of the neck conducting the
sound to the chamber, see Sheet No. 1, Figure 5, Sheet No. 2, Figure 4,
Letter A.
Secondly, Forks,-see Sheet No. 1, Figures 2 and 5, Sheet 2, Figures 4,
8, and 9, Letters B and H.-The forks in this instrument are nearly, like the
ordinary tuning fork. The shaft or handle, see Sheet No. 1, Figures 2 and 5,
Sheet No. 2, Figures 4, 8, and 9, Letter H, I prefer flat or square. The

page_text: !
lower forks are longest, gradually lessening in length until in the highest
notes they become very short. The forks for the F#, third octave, may have
prongs about four and a half inches long, three eighths of an inch wide, one
tenth of an inch thick, and one half or three fourths of an inch apart, with a
shaft or handle three inches long, if required, one eighth of an inch thick, and
same width as the prongs, and about a quarter (or more, if desired) of an inch
may be between the prongs of the fork. At about A or C in the fourth
octave the forks may be nearly like the common tuning fork, and the same
may be used by shortening the prongs only, and without any other alteration of
dimensions until you arrive at the top of the scale of sounds used in the
instrument, see Sheet No. 2, Figure 8. Forks may be made with shoulders
in the shanks or shafts, so that they may rest over "sole leather" or india
rubber on the fork rail (to be hereafter explained), and the holes or sockets
may be bushed with leather to prevent the contact of the rail with the fork.
This mode of fixing the forks applies more particularly to the third and lower part
of the fourth octave. In the upper part of the sixth octave, and in the seventh
and eighth octaves, the last when used will be best, with a shoulder to serve to
delicately hold or suspend them as in sockets, or inserted through thin leather,
or by small wires or cord, so as not to pinch or press too hardly the shanks
or shafts, and through all the forks the ends of the shanks or handles should
touch nothing, also through all the forks to be inserted in two parallel lines
of sole leather will be found very good. In fact the least possible play of the
forks (provided they are so permanently fixed as not to move too much) is
to be desired, which is in every way advantageous. In the upper part of the
fourth octave, fifth and sixth ditto, the forks may be even screwed in metal,
sometimes slightly bushing the holes with leather, and they answer perfectly well.
The forks may be thinned towards the ends of the prongs, gradually tapering
their whole length, and they agitate easier. Clumps on the ends may be
used, and the forks may be made much narrower throughout, particularly in
the upper tones. If it should be requisite a hole may be drilled through any
or all of the shanks of the forks for assisting in holding them if it should be
thought requisite, or it may be dispensed with.
Thirdly, the Fork Rail. For the different views and manner of fastening
in the fork rail and forks, see Sheet No. 1, Figures 2 and 5; Sheet No. 2,
Figures 7, 9, and 13, Letter J; Sheet No. 2, Figures 4, 8, 10, 11, 12, Letter I.
It stands obliquely to bring the tops of the forks in a horizontal line, as in
Sheet No. 2, Figure 8. The prongs point upwards, and match the upper line
of the mouths in the chambers behind them, and are arranged to correspond
with the keys and hammers. The fork rail may be made of brass, with single

page_text: The rail itself can rest on
or double row of screws to hold and regulate the forks, and in steps that the
forks may be at right angles with it. In the third octave, two or four forks in
each step; higher up, six or more in each step. For the upright supports or
props, see Sheet No. 2, Figures 7 and 8, Letter U.
leather. The props can be fastened against leather on the cross pieces in the
bottom of the case between the keys; see Sheet No. 2, Figure 7. Leather
or cloth between the forks and rail prevents in a great measure unnecessary
noise from the stroke. The rails should be supported on unvibrating mate-
rial, as leather or cloth; either "sole" or thinner leather, or india rubber, I
prefer.
Fourthly, springs, spring rack, and sounding board; see springs, Sheet
No. 1, Figure 2, &c., Sheet No. 2, Figures 8, 10, 11, 14, and 15, Letter K.
Spring rack, see Sheet No. 2, Figures 8, 16, and 17, Letter L; see sounding
board, Sheet No. 1, Figures 2 and 3, Letter M. Where the forks become
hard to agitate, and the chambers inconveniently large, springs are used to
complete the scale. They are best of steel, and the wire becomes longer as
the tones descend, for the lower tones cannot be produced by the shorter wires.
A difference in the curves, parallels, or angles, as may be in the same wire,
will vary the tone very much sometimes, by moving the inner curve, for
example, up or down. I think a superabundance of wire is to be avoided, as
a superfluous quantity has a great tendency to increase the harmonics. To
make a set of springs, use steel wire, which may be very well worked cold.
Iron and steel, same size and form, produce about the same note.
Let the
wire be, say, one eighth and a sixteenth (scant) of an inch in diameter for all
the lower twenty-five notes.
For about the form of the lower F, see Sheet
No. 2, Figure 14, Letter K. In ascending in the scale the size of the circle
gradually lessens, and the length of wire used varies some quarter of an inch
(scant) for each note. Suppose fifteen notes are made with circles, the lowest
which is F, may take twenty-two and a quarter inches. For the fifteenth
semitone or G, second octave, use about eighteen inches in length. The ten
notes above, ending on the third F from the lowest note, may be continued,
lessening their circumference and the length of wire. But suppose they are
made with parallels, the G, second octave, see Sheet No. 2, Figure 15,
Letter K 3, may be about fifteen and a half inches long; the longest parallel,
see Sheet No. 2, Figure 15, Letter X, about four and a half inches long; and
second parallel, see same Sheet and Figure, Letter Y, about three inches long.
The F, two octaves above the lowest note, and upper note of parallels, requires
about thirteen inches entire length of wire; first parallel, three and a half
inches long; second ditto, about one and a half inches long. For cach note

page_text: (the same nearly as in the circular form), the difference in the length of wire
is about one quarter of an inch. The stems or shanks of all these twenty-five
notes, whether circular or parallel, they may be, say, seven inches long. In
the calculations of the lengths of wire above given I have so considered them;
but all these measurements are liable to variations without injurious effects.
Of Tuning the Springs.-This is principally effected by changing the form of
the circle until the right note is produced, which, by opening and closing, will
raise or lower the note. The parallels are lowered by opening them, and
raised by closing them, &c. When the circular forms are perfectly made, they
will decrease so regularly as you ascend in the scale that dampers may be
applied to the loose ends of them; same with the parallels. To take a very
long wire to form the springs for the low notes, a harmonic sound will be
given for the note, which may be done, if desired, with the different forms;
but I think the best method, both as regards tuning, manufacture, and quality
of tone, is to use no more circles, parallels, &c. than those given in the
Drawings above referred to for any note. In the same length and form of
two wires, of different sizes, the larger will tend to the higher tone of the two.
A spring that does not sound well may by a slight difference in the bending
be much improved. For circular, angular, parallel, and other forms, see
Sheet No. 2, Figures 14 and 15. These are found to answer very well.
Cutting off the end of a spring tends to raise, or, by filing thinner, to lower
the note. The vibrating forms of springs are very various; for some of
them, see Sheet No. 2, Figures 14 and 15, Letter K. The springs are
firmly fastened at one end to a rack by rivets or screws at equal distances
(that is, at the width of the keys), that is where only one is used to
a note. Two may be used, which augments the quantity of tone; in the
present description only one to a note is taken into consideration. This rack
is placed on a sounding board, which lays in the bottom of the instrument, and
under the bottom cross pieces of the case; it may be made as here represented
or inclosed like a sounding box, or in various ways, barred if you please, not
too thick; about a quarter of an inch thick will answer, more or less. Thin
sheets of wood between the springs may be used, which seems to soften and
enrich the tone, but in such case the damper wires must be before or back of the
springs; or there may be two or more sounding boards, one projecting a trifle
above the other, that is, one may lay at a little elevation above the other, of a
different thickness and smaller if it is preferred for the upper springs; in such
case a corresponding number of shanks or racks would be required. The
shank, see Sheet No. 2, Figures 8, 16, and 17, Letter E, of the rack, may be
half an inch wide, more or less, and a quarter or more or less thick, resting

page_text: on the sounding board through a mortice cut in a small piece of rather hard
wood glued fast to the said board, about the middle of it, to keep the shank
from moving about; there may be, if desired, more shanks coming to the board.
The ends of the rack are secured by rods circular and straight, see Sheet
No. 2, Figure 11, Letter N, extending to the back and end of the case. The
rods should be sufficiently stiff, resting on hooks at right angles with them at
the end of the rack, and be screwed into it. The spring rack may have a
fastening, if desired, through a hole, so as not to jar in its shank near the top
of it, or fitted closely into the crotch of the said rack by a pin, with a nut or
screw which attaches to a cross piece, see Sheet No. 2, Figures 8, 10, and
11, &c., Letter A", which cross piece is to be screwed into the top of the cross
pieces in the bottom of the case. For two other forms of rack, see Sheet 2,
Figures 16 and 17. These racks may either of them be substituted for the
one in Figure 8. Any of the racks may be made of cast brass or of iron or
steel forged or cast. The springs rise perpendicularly for about six or seven
inches above their fastenings until in a horizontal line with the forks when
they bend towards the back of the instrument into their various forms.
Sixthly, Dampers and general bringing together of the Parts.-The dampers
(see Sheet No. 1, Figures 1, 2, 3, Sheet No. 2, Figure 14, Letter R), are
hinged on a frame at the back and top of the instrument; they are horizontal
and are at right angles with the back near which they are hinged, on lower sides
and front ends of which there are damper heads. These heads may be, variously
made, resting on the horizontal line and ends of the springs and forks under
the dampers. On one or both the prongs and back of the forks are placed the
chambers, see Sheet No. 2, Figures 1, 2, and 3. Just under and before the
damper heads and horizontal line of the forks and springs are the hammer
heads, see Sheets No. 1, Figures 1, 2, 3, each hammer head fronting a fork or
spring perpendicularly under the dampers and hammers; and in front of the
range of chambers, forks and springs are the keys, see Sheet No. 1, Figures 1,
2, 3, and 5. From the back ends of the keys to the front ends of the
dampers above are damper wires, which may even pass directly through the
chambers a quarter of an inch back of the mouths, or as in the Drawings,
see Sheet No. 1, Figures 2 and 5, Sheet No. 2, Figures 4, 8, and 10, Letter S,
which, as the back ends of the keys rise, they lift the dampers off the springs
and forks by the same motion that throws the hammers against them. The
chambers and fork rail may be all so arranged over a table, see Sheet No. 2,
Figure 8, Letter T, as all to be taken out together. The fork rail may, if
thought best, rest on the props fastened to the cross pieces in the bottom of the

page_text: instrument, see Sheet No. 2, Figure 7, Letter U. The spring rack must be
fastened with screws and nuts, see Sheet No. 2, Figures 8 and 11, to take out
as a separate fixture after removing the damper wires, which must also take
out separately from the springs. The tops of the chambers, by a slight projec-
tion, or having the damper wires pass directly through them about a quarter of
an inch back from their mouths, will serve for the upper damper rail for the
damper wires in the rear of the forks. For the lower damper rail, see
Sheet No. 2, Figure 8, &c., Letter Z. The upper and lower damper rail for
the springs, see Sheet No. 2, Figure 8, &c., Letter Z, are strips of wood
running right and left, attached to two upright side pieces, which are all suffi-
ciently strongly fastened together and screwed on to the cross pieces of the
bottom of the case. For the cross pieces of the bottom of the case, see
Sheet No. 1, Figure 3, Letter B*; for the damper rails of springs and forks,
see Sheet No. 1, Figures 2 & 5, Sheet No. 2, Figures 8, 10, &c., Letter Z;
see Sheet No. 2, Figures 8, 10, 14. The action used in illustrations is like
the upright cottage pianoforte, and the tones correspond with the key board in
chromatic succession. The touch should be very quick and more delicate
against the forks than in the pianoforte, see on Sheet No. 1, Figure 1, the
front elevation; No. 2, the end elevation; No. 3, the plan or top view.
Seventhly, sundry and additional Remarks.-The hammers in the bass oppo-
site springs must be soft and large, similar somewhat to the pianoforte, see
Sheet No. 2, Figure 14, Letter W. Opposite the forks the wooden part of the
hammer heads must be quite pointed, see Sheet No. 2, Figure 4, Letter V, and
covered with leather or cloth, and gradually harden as they ascend until near
and above the sixth octave. Above this a point of wood or metal will bring
out the tones, or a very little leather, such as sheep's skin, may be used over
the hammer head. The forks about the upper part of the sixth octave, and above,
depend much less on the chambers than those below. These chambers, though
smaller than ladies' thimbles, yet improve the tone. Forks may be used in the
seventh and eighth octaves without any chambers with good effect. Forks of the
same size, say three inches long in the prongs, when shortened one inch will
raise it about one octave; one and a half inches taken off, about two octaves, &c.
Chambers may be applied to the springs, but they do not improve the tone
very much, and this size would be inconveniently large. If a small weight
be fastened to the loose end of a spring, it will lower it and rather impair it;
by having a thread cut on the loose end of it, with a nut to screw up, will alter
the tone. Lower springs may (or not) be wrapt with fine wire. Springs of
iron will do passably well. The chambers may be made of almost any hard

page_text: substance and of almost any form; the spherical perhaps is the best, the narrow
the most compact. The same capacity of different materials of different sub-
stances gives different tones. The soft pedal may be made by interposing soft
material between the hammers, forks, and springs, or by moving the chambers
back from the forks, which would require a mechanical construction to effect
this object. The pedal for raising the dampers any mechanic or pianoforte
maker can very easily adjust, as there is abundance of space for it. The case
is susceptible of various forms, &c. The keys need not be near so long as
those of the pianoforte. Opposite the springs, should the damper wires be
placed behind them, the keys must be longer. Strings like the pianoforte in*
cottage form, may be used for the lower part of the instrument. A piano-
forte maker can easily combine the two principles; the sounding board for the
bass would thus require a different construction, but as there is sufficient
room for the purpose, it would be the easiest thing to fix it. There may be
added to any pianoforte, in the proper form for the object or purpose, such a
number of tones, particularly in the three or four upper octaves, as desired,
and they will be found preferable to the strings of the pianoforte, as they are
much longer in duration, and better tone, and always in tune.
Having now described the nature of my said Invention, and the manner in
which the same is to be performed and carried into practical effect, I wish it
to be distinctly understood, that I claim as my Invention,―
Firstly, the air chambers as applied to tuning forks, springs, or any other
vibrating material, as applied to musical instruments; and the tuning fork
or spring, or vibrating material, as applied to the air chamber in musical
instruments.
Secondly, the springs by the medium of a rack applied to a sounding
board, as applied to musical instruments, and the peculiar forks and manner
of using them to produce the higher and more acute notes and tones in said
instruments.
Thirdly, I claim the mechanical combinations and arrangements of parts,
by which my Invention is carried into practical effect, as constituting a
mode or modes of producing musical sounds in musical instruments, as
herein-before particularly described and set forth, and represented by the
Drawings hereunto annexed.
In witness whereof, I, the said Ureli Corelli Hill, have hereunto set my
hand and seal, this Twentieth day of August, in the year of our Lord
One thousand eight hundred and forty-seven.
U. C. (L.g.) HILL.

page_text: AND BE IT REMEMBERED, that on the Twentieth day of August, in the
year of our Lord 1847, the aforesaid Ureli Corelli Hill came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, 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 Twenty-eighth day of December, in the year of our Lord
One thousand eight hundred and forty-seven.