CERTAIN IMPROVEMENTS IN MUSICAL INSTRUMENTS, AND IN APPARATUS TO BE USED IN CONNECTION WITH MUSICAL INSTRUMENTS
Year: 1848

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I CHARLES
DAWSON, of Hardinge Street, Islington, in the county of Middlesex, Professor
of Music, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Second day of November, in the
twelfth year of Her reign, did give and grant unto me, the said Charles
Dawson, his exors, adñiors, and assigns, Her especial licence, full power, sole
privilege and authority, that I, the said Charles Dawson, my exors, adññors,
and assigns, and such others as I, the said Charles Dawson, my exors, admors,
or assigns, should at any time agree with, and no others, should and lawfully
might make, use, exercise, and vend my Invention of "CERTAIN IMPROVEMENTS
IN MUSICAL INSTRUMENTS, AND IN APPARATUS TO BE USED IN CONNECTION WITH
MUSICAL INSTRUMENTS," within that part of the United Kingdom of Great
Britain and Ireland called England, Her Dominion of Wales, and Town of
Berwick-upon-Tweed, and also in the Islands of Jersey, Guernsey, Alderney,
Sark, and Man, and in all Her Colonies and Plantations abroad, during the
term of fourteen years next ensuing; in which said Letters Patent there is
contained a proviso, requiring that I, the said Charles Dawson, shall particu-
larly 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 cause the same to be enrolled in Her said Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said in part recited Letters Patent, as, reference being thereunto"
had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Dawson do hereby declare that the nature of my Invention, and the
manner in which the same is to-be-performed, are particularly described..and
ascertained in and by this present Specification or instrument in writing,
reference being had to the several Drawings hereunto annexed, and in which
said several Drawings similar parts are marked and referred to by similar
letters or figures (that is to say):
The first part of my said Invention consists of a mode or modes of pro-
ducing various notes on wind musical instruments, and which notes I produce
upon an instrument constructed according to this part of my Invention by
means or with the aid of a moveable tube or sliding plate, placed within the
instrument and having orifices communicating with chambers placed along the
side of the instrument, such chambers being furnished with orifices to be
stopped or opened by the fingers or keys in the usual manner for the purposes
of producing the notes.
In Figs. 1, 2, 3, and 4, of the said Drawings hereunto annexed, I have
shewn the mode in which I apply the first part of my said Invention to
German flutes. Fig. 1 represents a longitudinal section, and Figs. 2 and 3
transverse sections through the lines A, A, and B, B, on Fig. 1, respectively,
of a portion of such a flute. a, a, is an internal metallic tube fitted so
as to be air-tight, but slide freely within the outer tube b, b. A double
key or lever c is at its centre mounted upon a pin or axis e, and is pro-
vided with springs d, d', which will niaintain each end of the lever equally
distant from the exterior of the flute unless pressure be applied at either end.
The pin or axis e of this lever is supported by arms f, f', projecting from the
lower side of the outer tube b, and entering into openings in the lever as
shewn in Fig. 4, that Figure being a view of the key or lever c, as seen when
looking towards the instrument. The lever c is furnished with arms g, g³,
which embrace the sides of the outer tube and have slots in their sides to
receive the pins h, h'. The pins h, h', are fixed to the inner tube a, a, and
project through slots i in the slides of the outer tube in which they work, and
are capable of sliding freely. When either end of the key or lever c is pressed
towards the tube, the arms 9, 9', will act upon the pins h, h¹, fixed to the inner
tube, and cause that tube to move in one direction on the other within the
outer tube according to the end of the key or lever to which the pressure may
be applied.
The finger holes used in playing the flute, and to which the fingers are to
be applied, are made in chambers (in the Figures marked k), formed or fixed
upon the outer tube of the flute. Each of these chambers is open at the

page_text: bottom, and is only closed by the inner tube a, a, through which there is an
orifice l forming a communication between the interior of the flute and the
chamber, and through the chamber with the finger hole m. It is well known
that in such instruments as the flute, flageolet, and clarinet, the ordinary finger
holes will not enable a performer conveniently to produce all the notes required.
in performing musical pieces, and therefore such instruments are now generally
furnished with various keys for enabling performers to produce the various
notes required; but notwithstanding the addition of such keys to such musical
instruments they are still not capable of producing notes of all the various
descriptions or degrees of pitch which the performer may desire, and the per-
former frequently finds considerable difficulty in gliding from one note to
another. In a flute constructed in the manner now described, the inner tube
a, a, may by means of the key or lever c be moved up or down as the per-
former pleases, and he is thus enabled to vary the note or pitch of the tone
which would otherwise be produced by any particular fingering of the instru-
ment, and so obtain the ordinary semitones (as they are commonly called), and
many other notes which could not be produced from instruments of the ordinary
construction. And it is hardly necessary to say that if the pitch of the tone
which would be produced by any particular fingering is to be raised, the inner
tube must be moved upwards towards the top of the flute or embouchure, and
when the pitch is to be depressed, the inner tube must be moved in the
opposite direction. As in a flute constructed in the manner just described all
the orifices are placed along one side of the flute, a sliding plate may be used
in lieu of the sliding tube, the plate being made to fit against that side of the
instrument upon which the chambers are placed, as before mentioned, and
orifices being made in the plate for the purpose of making a communication
between the inside of the flute and each of the chambers, in the manner
as herein-before described with reference to the sliding or moveable inner tube..
When a plate is used in lieu of a tube, I make the concave surface of it with
the same curve as the interior of the flute, so as to make the interior a com-
plete circle, and I sink the plate into the substance of the flute, making the
edges of the plate to work in grooves, as shewn in Fig. 5, which figure repre-
sents a transverse section of the tube of a flute so constructed.
Instead of making the tube to move up and down within the flute in the
manner which has been described, the tube may be made so as to be capable
of a circular motion only within the flute, but the orifices in the tube intended
to form the communications between the interior of the flute and the chambers
are to be cut longer and spirally in the tube, so that by turning the tube in
the one direction or the other, the part of the orifices which may form the com-

page_text: munications with the chambers, may be nearer to or further from the embou-
chure, as may be required by the performer for producing variations in the
pitch of the notes. For the sake of greater perspicuity, I have described the
application of this part of my said Invention to a German flute only, but the
mode of applying this part of my Invention to various other wind musi-
cal instruments, the notes of which are produced by closing or opening
lateral orifices, is the same in substance as that which has already been
described.
The second part of my said Invention consists of a mode or modes of pro-
ducing various notes on wind musical instruments. and which notes I produce
upon an instrument constructed according to this part of my Invention by
means of a longitudinal valve or longitudinal valves, by the aid of which a
performer can open the side of the instrument at such part or parts as may be
requisite from time to time for enabling him not only to produce various notes
upon the instrument, but also to subdivide many parts of the musical scale to a
greater extent than has hitherto been attained on such instruments.
A flexible and elastic
In Figures 6, 7, 8, 9, 10, 11, and 12, of the Drawings hereunto annexed, I
have shewn one mode of carrying this part of my said Invention into effect.
Fig. 6 is a longitudinal section of. parts of a German flute constructed accord-
ing to this part of my Invention, shewing a single valve placed along one side
of the flute. Fig. 7 is a plan or view of that side of the flute upon which the
valve is placed. Figs. and 9 are transverse sections of the instrument, as
taken through the lines C, C, and D, D, respectively, of Fig. 6. This flute is
made of metal, and is curved, as shewn in Fig. 6. Along one side of this
instrument is made a slot a, formed with lips c, c, as shewn in Fig. 10, which
represents a transverse section of the tube of the flute.
longitudinal valve or band d, d, is formed, with a rib or projection along one
side of it, this rib being intended to project through the slot, and when the
valve is not pressed down to project beyond the exterior of the flute. This
valve is made of a spiral metallic spring of the form, and covered with leather,
india-rubber, or other convenient material, in manner shewn in Fig. 12, which
is an enlarged perspective view of part of this valve or band. Instead of
making the valve of a metallic spring, covered with leather or india-rubber,
the valve may be made entirely of india-rubber, or of any other material proper
for the purpose. The longitudinal valve is to be made sufficiently wide to fill
up the interior part of the slot a, and so that the projecting sides or edges of it
may lie or press against the lips c, c, of the slot.
The valve or band is fastened at each end by a pin e, and it is to be stretched
between the two pins e, e¹; to such a degree as to cause the projecting sides or

page_text: edges of it to be pressed against the lips c, c, of the slot, and the tube of the flute
is made in a curved form, as shewn in Fig. 6, for the purpose of more easily
obtaining the requisite degree of pressure by the sides or edges of the valve
against the lips of the slot. It will thus be seen, that when the valve or band
d, d, is stretched and fixed in its place, the slot will be closed by it, so as to
prevent the passage of any air through it; but if any part of the rib of the valve
d be pressed by the finger, so as to force a part of the valve inwards and away
from the lips c, c, as shewn in the transverse section, Fig. 11, and indicated
by the dotted lines at p, in Fig. 6, an opening will be made for the passage of
air from the tube a, and when the pressure of the finger is removed the band
d, d, will again return to its place and close the slot. In a German flute of
the ordinary construction, notes are produced differing from each other in pitch
by means or with the aid of lateral orifices placed at certain parts of the
instrument, the position of which, however, the performer has no power to
vary; but in a flute constructed with a longitudinal valve, as herein-before
described, the performer is at liberty to press his finger upon any part of the
valve for the purpose of obtaining an orifice there, and may thus produce not
only the various notes usually obtained upon the flute, but also many other
notes which could not be produced upon a flute of any ordinary construction.
Instead of constructing a flute with a single longitudinal slot and valve, it may
be made with several of such slots and valves, as shewn in Fig. 13, each of the
slots and valves in that case being made shorter, but so that the whole of the
slots and valves will together extend the same distance along the flute as the
single slot and valve would. And in this case I arrange the slots and valves
in two lines, as shewn in Fig. 13, in order to enable the performer to produce
an orifice or opening at any part or parts in the same way as if there was one
continuous slot and valve. I have described the details of this part of my said
Invention also as applied to a German flute only; but the mode of applying
this part of my Invention to various other wind musical instruments, the
notes of which are produced by closing or opening lateral orifices, is similar to
that, which I have described in connection with a German flute.
The third part of my said Invention consists of apparatus to be applied to
the key boards of pianofortes, organs, musical instruments played by means of
similar key boards, and which apparatus is applicable for preventing the action.
of all or any of the keys of the board used for sounding such of the notes as do
not occur in the key of any piece to be played. I have in Figs. 14, 15, 16,
and 17, of the said Drawings hereunto annexed, shewn the mode of con-
structing the apparatus which forms this part of my Invention, and the
manner in which it is applied to the key board of a pianoforte. Figure 14 shews

page_text: a_plan_of_part_of_a. key board, and of the said apparatus; Figure 15 is a
section on the line E, E, on Fig. 14, and Fig. 16 is a section on the line F,
F, on Fig. 14. a, a, are the keys of the instrument; b is the name board;
ć portions of the casing, all of which are of the ordinary description; d, d, is a
roller, which is placed behind the name board, and also behind the centre pins
upon which the keys move, upon which roller projections c are fixed, in
manner herein-after described. This roller extends from side to side of the
key board, and the axes of it are at each end supported in suitable bearings,
fixed upon the framing of the instrument. The roller must be placed at such
a distance above the surface of the keys of the key board as will allow that
part of each key which is under it to be raised in the usual manner, when the
action of such key is not intended to be prevented, as is shewn in Fig. 17.
Upon
one end of the axis of the roller is fixed a toothed bevilled wheel g, geared
into another bevilled wheel h, which is fixed on a spindle i, and that spindle is at
one end mounted in a suitable bearing, the other end of it passing through the
name board, and having a pointer fixed upon it, as shewn at k, Fig. 14. Upon
the name board, and surrounding the spindle of the pointer is an index plate,
marked so as to shew the extent to which the spindle and consequently the
roller is to be turned in order to bring any part of the roller which may be
desired into operation. The outer end of--the spindle projects a little beyond
the pointer, and that projecting part is squared, so as to receive a key l, by
means of which the spindle may be turned. Upon the roller d are placed pro-
jections e, which partly encircle the roller, and which are not quite so wide as
the keys upon which they are to act, and the height of each of these pro-
jections must be such, that when turned down to the under side and next to the
key against which it acts, it will (in manner shewn in Fig. 16) prevent that
key from being used so as to produce a note. I divide the circumference of the
roller into twelve equal parts, that being the number of the major keys of the
diatonic scale, in which music can be played, and I place the projections already
mentioned upon the roller, in such a manner that each line or point of separation
between those divisions will be appropriated to one or other of the twelve keys
of the diatonic scale. The order in which these projections are placed upon
the roller will depend upon the order in which the different keys of the scale
may be desired to be arranged or produced. The chief object of this apparatus
being to assist the teacher in the instruction of pupils, it is hardly necessary to
place any projections upon the roller to act upon the keys used for playing
what are usually called the sharp or flat notes, but merely to apply the
apparatus to the long keys used for producing what are usually called the
natural notes, those being the keys which pupils are most apt to strike

page_text: improperly, so as to produce false or incorrect notes.
For this reason, there-
fore, I ordinarily apply only seven projections upon the roller for each octave;
but, of course, the same principle may be carried out and extended to each of
the twelve keys in every octave of the board. The line or point upon the
roller intended to be used in the key of C major will, of course, in this mode of
arranging the apparatus, be entirely without any projection, and although any
other order of arranging the keys may be adopted, I prefer to arrange them
according to a usual order of modulation, as herein-after described. One of
the before-mentioned lines or points of the roller being appropriated to the
natural key of C major, I appropriate the next to the key of G major,
and, therefore, I place projections upon the roller to act upon or fix every
F natural key of the key board so that it cannot be used to produce a note.
And as according to the arrangement just mentioned, the F natural keys of
the board will not be required in the next four keys of the scale, I continue
the projections just mentioned to the fourth of the nextly following lines or
points of division upon the roller. The next key in order of modulation being
D major, I make, at the next line or point of division upon the roller, a
projection to act upon or fix every C natural key of the board, in like manner
as just described with respect to the F natural keys, and, as before mentioned,
continue those projections to the fourth of the next following lines or points of
division upon the roller. The next key in order being A major, projections
are to be made for acting upon the G natural keys, and those projections
carried forward as before, and in like manner proceeding with the other keys,
projections must be made for acting upon the D natural keys of the board in
the key of four sharps, upon the A natural keys in the key of five sharps, upon
the E natural keys in the key of six sharps or six flats, and upon the B
natural keys in the key of seven sharps or five flats, the projections being in
each case continued to the fourth line or point of division upon the roller as
before mentioned. As according to this arrangement the keys for producing
the sharp and flat notes are always left at liberty, the remaining keys of the
scale will be produced without adding any other projections to the rollers than
those already described. The index plate should be marked in the order in
which the projections on the roller are arranged, so that by turning the
pointer to any particular key marked on the index plate the appropriate
division of the roller may be turned down and its projections brought into
action. In Fig. 18 I have shown the manner in which I mark an index
plate when the apparatus is arranged in the manner which I have described,
the names of the several key notes being marked upon the index plate, but

page_text: the index plate may be marked with numbers or in any other way which
might be deemed most convenient. -
The fourth part of my said Invention consists of a mode or modes of
constructing additional keys or apparatus to be applied to or used in connexion
with the key boards of pianofortes, organs, and other musical instruments, played
by means of similar key boards, for the purpose of enabling the performer by
the movement of a single finger to cause two or more of the keys of the board
to be acted upon so as to produce two or more notes at the same time.
Figures 19, 20, 21, 22, 23, and 24, of the said Drawings hereunto annexed,
shew the mode of constructing the apparatus forming this part of my said
Invention, and the manner in which it is applied to the key board of a piano-
forte. Fig. 19 represents a plan of part of the key board of a pianoforte with
part of an apparatus constructed according to this part of my Invention applied
thereto. Fig. 20 is a section of the same parts as taken through the line
G, G, in Figure 19. Figs. 21 and 22 are also sections of the same parts,
shewn as taken through the lines H, H, and J, J, respectively.
The parts
of a key board and keys, shewn in these Figures, are of the ordinary
construction. a, a, are the keys; b, b, is the name board; and c, c, portions
of the casing of the pianoforte. The purpose of this part of my Invention
is attained by means of additional keys or levers which are attached to a
series of spindles or rods d, d, mounted upon axes, and placed in a horizontal
position above the key board and behind the name board. These spindles or
rods are made of metal, and their axes are mounted in suitable bearings in a
metal frame e, fixed behind the name board. The bearings are lined or bushed
with a soft material in the ordinary manner to prevent noise, and between the
bearings and the ends of the rods washers of a soft material are placed for the
same purpose. Upon each of these rods are fixed two or more sockets f, f
(two only being shown in the Figures,) into each of which sockets is to be fixed
a key or lever g, made of wood, or other convenient material, as shewn in
Figures 23 and 24, these keys or levers being made sufficiently long to
extend from the rods to which they are respectively attached, and to protrude
beyond the name board (a part of which is cut away to permit them to come
through), and rest upon the tops of the ordinary keys of the key board, upon
which they are respectively intended to act, as shewn in Figures 19, 21, and
22, and so form a series of additional keys, which the performer may use in
playing or not, as he may think proper. The lengths of those parts of the
additional keys or levers which are behind the name board vary according to
the distance of the rods to which they are affixed from the name board. The

page_text: parts of the additional keys or levers which protrude beyond the name board
are faced with ivory, or other suitable material, so as to make them smooth for
the finger, in the same way as the ordinary keys, and they may be made of
different lengths, and colored differently, so as to distinguish those which are
intended to act on the long keys of the key board, from those which are
intended to act on the short keys, as shewn in Figure 19. The rods already
mentioned are all mounted on the same horizontal plane, or nearly so, and one
behind another at such a distance from each other that they will turn or move
freely as far as necessary without coming into contact with each other. Each
rod is also placed so that each of the keys or levers mounted at the ends of it
shall be immediately above the ordinary key of the key board, upon which it
is intended to act as shewn by the dotted lines in Figure 19. The mode of
mounting these rods in their frame is shewn more clearly in Figure 23, which
is a view from the underside of two of these rods, with their keys or levers so
mounted. Fig. 24 is a perspective view of one of these rods, with a pair of
keys or levers fixed upon it, the keys or levers shewn in this Figure being
intended to act upon two of the long ordinary keys of the key board. The
additional keys or levers are shaped in such a manner that their outer ends
will rest upon the ordinary keys, upon which they are to act, and in a
convenient position for being operated upon by the fingers of the performer.
To prevent noise, the ends of these additional keys or levers have pieces of
leather, or other soft material placed on their under sides, where they touch the
ordinary keys upon which they act, a pair of additional keys or levers being
firmly fixed upon a rod in the manner described. If the key or lever at one
end of the rod be pressed down by the finger, the key or lever at the other end
must also be pressed down at the same time, and thus the performer acquires
the power, with an apparatus constructed in the manner described, to strike
two keys, and to produce two notes at the same time. In the apparatus
shewn in the Figures, the two ordinary keys acted upon by each pair of
additional keys or levers are octaves to each other; but pairs of additional
keys or levers may, however, be mounted upon spindles or rods in the manner
I have described, nearer to or further from each other, and so that the two
ordinary keys of the board acted upon by each pair of additional keys may be
fifths or tenths to each other, or sound any other chord which may be desired.
And it will be observed that the number of pairs of additional keys or levers,
which will be contained in a set of apparatus constructed according to this part
of my Invention, will depend upon the interval between each pair of such
additional keys, and will be equivalent to the number of semitones contained
in that interval. Three or four additional keys or levers might also be

page_text: mounted upon each spindle, in the same manner as already described, so as to
enable the performer by the movement of a single finger to cause three or four
of the keys of the key board to be acted upon at the same time.
I have only
shown the apparatus extended to twelve pairs of additional keys, this being I
believe the most convenient number, and I prefer to furnish pianofortes with
two such apparatus, the one apparatus being placed in a convenient position in
connection with twelve of the ordinary keys of the upper part of the key board,
and the other apparatus being placed in a convenient position in connection
with twelve of the ordinary keys of the lower or left hand part of the key
board, so as to enable the performer, by means of this part of my Invention,
with one hand to have a more extensive command over one half of the key
board, and with the other hand to have a more extensive command over the
other half of it. But if,a pianoforte should be intended to be used chiefly for
two persons to play upon, it may be desirable that three sets of apparatus
made according to this part of my Invention should be added to the instrument.
The fifth part of my said Invention consists of a mode or modes of con-
structing apparatus for admitting and regulating the admission of air to the
pipes or other parts of organs, and other musical instruments, so as to produce
the required notes, in manner herein-after described. In Figures 25, 26, 27,
and 28, I have shewn the mode in which I construct certain parts of an organ
according to this part of my Invention. In Figure 25 is represented a
longitudinal section, and in Figure 26 a transverse section of such an organ;
a, a, are the bellows and regulator constructed in a manner usually adopted in
making barrel organs, and these bellows are put in action by cranks b, on a
shaft c, which is turned by means of a winch or handle in the usual manner.
Two rollers d and d' are mounted in suitable bearings at the sides of the instru-
ment, and are caused to revolve in the direction indicated by the arrows for the
purpose of drawing the paper or other thin material, herein-after described,
between the bottoms of the air channels, and the leather or flexible top of the
chamber p. These rollers are put in motion by wheel work, mounted at the side
of the instrument, and connected with the crank shaft c, as shewn in Figure 27;
f is a toothed pinion fixed to the crank shaft, and gearing into a toothed wheel
g, to which is affixed a pinion h, which gears into a wheel i, and this wheel
i gears into a wheel j, these wheels i and j being affixed to the ends of the
axis of the rollers d and d¹ respectively. The rollers d and d' are pressed
together by springs acting on their bearings, so that a sheet of paper or other
thin material inserted at and passing to them from the shelf m will be drawn
along by the action of the rollers, and a curved board and shelf w, w, are fixed
behind and below the rollers, so that such a sheet, after passing between the

page_text: rollers, will be turned back, in the manner indicated by the red line 7. The
shelf m is mounted upon hinges at m¹, and under the moveable end of this
shelf is placed a cross bar e, which is pressed upwards by the springs n, n.
This cross bar e is connected at each end by means of rods t and t¹, with
valves u and u¹ opening downwards in the air passages v and v¹, so that by
pressing down the shelf m air may be permitted to flow up from the bellows to
the pipes of the instrument. The moveable end of the shelf m is notched.or
formed with projections, which are made to fit accurately at their sides into
corresponding notches in the upper board o, o, as shewn in Figure 28, that
Figure being a transverse section of part of the apparatus shewn, as taken
through the line K, K, on Figure 25. These notches allow the projections of the
shelf m to be pressed up by the springs n, n, acting on the cross bar e suffi-
ciently high to cause the valves u and u¹ to be closed; but when the shelf is
depressed, and any thin material such as paper is pushed over the moveable end
of the shelf m so as to be drawn forward by the rollers, the paper or other thin
material will prevent the projections at the end of the shelf from passing up
into the notches in the board o, o, above, and will thus keep down the shelf m
and the cross bar e sufficiently far to keep the valves u and u¹ open for the
passage of air up to the instrument through the chamber p. The chamber p
is covered on its upper side with leather or some other flexible material, which
is or can be made sufficiently air-tight, and this covering is perforated with a
number of holes, there being one hole made immediately below, and of the
same size as each of the openings of the air channels q, q, which lead up to the
pipes of the instrument, so that a sheet of paper or thin material being inserted
between the covering of the chamber p and the channels q, q, above it, no air
can pass from the chamber into any of those channels, unless there be some
perforation in that part of the sheet which happens to be placed between some
hole in the covering of the chamber p and the corresponding opening of the
channel above. The covering of the chamber p is made flexible for the
purpose of preventing the escape of air from the chamber in any other way
than into the air channels 2, 2; and this is effected by the air (when it is forced
into the chamber) pressing the covering of the chamber up against the sheet of
paper or other thin material, and also pressing the sheet of paper or other thin
material against the bottoms of the air chambers. Fig. 29 represents a portion
of a sheet of paper or other thin material, perforated so as to admit and
regulate the flow of air up to the pipes which are to be sounded; one end of
this paper or thin material is to be passed along the shelf m, and entered
between the rollers d and d', so that by their action it may be drawn along the
covering of the chamber p and the air channels 2, 7. The holes are made in

page_text: I
Each of the air
the sheet of paper or thin material in proper places for allowing the passage of
air up to each of the pipes as it is intended to be sounded. The width of
each hole in the sheet of paper is equal to that of the opening of the air
channel below which it is to be drawn, and the length of the hole must be
made in proportion to the intended duration of the note which is intended to
be sounded, as the sheet of paper is drawn along by the rollers. The number,
duration, and succession of the notes to be sounded by the instrument may in
this way be regulated at pleasure, and the time may also be regulated by the
degree of speed given to the rollers when they are in motion.
channels leads up to a set of pipes of the ordinary description, and which may,
of course, be varied in any manner that shall be desired; and the instrument is
furnished with stops and a swell of the ordinary description. The sides of the
sheet of paper or other material, perforated in the manner above described,
must be cut straight, and so as to fit exactly between the side pieces x and a¹
of the board o, o, in order that the sheet may not vary from the proper line of
course which is requisite, in order to cause the holes of it to be brought
accurately to the places at which they are to admit the passage of air into the
various air channels. The width of the opening into each of the several air
channels being the same, and those openings being placed at the same distance
apart, the construction of the shelf m and the parts connected with it may be
varied, so as to enable the performer, by moving the sheet of paper or other
thin material to the one side or the other, to cause it to be drawn through
under a different series of openings or air channels, and thus transpose the
music produced by the instrument. I have described the air channels q, q, as
leading up to pipes or sets of pipes (such as are usually placed in organs), and
which are to be sounded by means of currents of air passing up through the
perforated sheet of paper or thin material before mentioned; but instead of
these air channels leading up to such pipes they may be made to lead up to
a set or sets of instruments of any other description, which can be sounded by
means of currents of air, or they may be made to lead up to a set or sets of
any other description of apparatus, from which a succession of musical sounds
can be produced. One great advantage resulting from the use of a sheet or
sheets of paper or other thin material in the way which I have described is,
that such sheets can be prepared at a small cost, and thus instruments of the
description I have mentioned may be made to perform a large number of
pieces without incurring any very serious expence.
Having now described the nature of each of the several parts of my said
Invention, and the manner in which it is to be performed, I hereby declare
that I claim as of my said Invention,―

page_text: Firstly, the mode or modes of producing notes upon wind musical instru-
ments, by means of moveable tubes or plates, having orifices communicating
with lateral chambers, in manner herein-before described.
Secondly, the mode or modes of producing various notes on wind musical
instruments, by means of a longitudinal valve or longitudinal valves, in manner
herein-before described.
Thirdly, the mode or modes of constructing apparatus for preventing the
action of some of the keys of musical instruments, in manner herein-before
described.
Fourthly, the mode or modes of constructing additional keys or apparatus
to be applied to the key boards of musical instruments, so as to enable a
performer, by the movement of a single finger, to produce two or more notes
at the same time, in manner herein-before described.
And, fifthly, the mode or modes of constructing apparatus for admitting
and regulating the admission of air to pipes or other parts of musical instru-
ments, so as to produce the required notes, in manner herein-before described.
In witness whereof, the said Charles Dawson hath hereunto set his hand
and seal, this Second day of May, in the year of our Lord One thou-
sand eight hundred and forty-nine
Enrolled the Second day of May, in the year of our Lord One thousand
eight hundred and forty-nine.