CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OF ORGANS
Year: 1810

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
LISTON, of Ecclesmachan, in the County of Linlithgow, Clerk, and CHARLES
BROUGHTON, of the City of Edinburgh, Writer to the Signet, do send greeting.
WHEREAS His most Excellent Majesty George Third, by Letters Patent
under the Great Seal bearing date at Westminster, the Third day of July, now
last past, did give and grant unto us, the said Henry Liston and Charles Brough-
ton, our executors, administrators, and assigns, His special licence, full power,
and sole privilege, and authority, that we, the said Henry Liston and Charles
Broughton, our executors, administrators, and assigns, and every of them, by
ourselves, or by our deputies, servants or agents, or such others as we, the said
Henry Liston and Charles Broughton, our executors, administrators, 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, shall and lawfully
may make, use, exercise, and vend, our Invention of "CERTAIN IMPROVEMENTS IN
THE CONSTRUCTION OF ORGANS," within that part of His United Kingdom of Great
Britain and Ireland called England, His Dominion of Wales, and Town of
Berwick-upon-Tweed; in which said Letters Patent there is contained a
proviso obliging us, the said Henry Liston and Charles Broughton, or one of
us, particularly to describe and ascertain the nature of our said Invention, and
in what manner the same is to be performed, by an instrument in writing

page_text: under our hands and seals, or under the hand and seal of one of us, and
cause the same to be inrolled in His Majesty's High Court of Chancer
within two calendar month and immediately after the date of the sai
in part recited Letters Patent, as in and by the same, relation being
thereunto had, may more fully and at large appear, otherwise the said Letter
Patent to be void.
NOW KNOW YE, that in compliance with the said proviso, we, the said
Henry Liston and Charles Broughton, do hereby declare that our Invention
consists, first, in causing each organ pipe to afford several tones, differing from
each other in acuteness or gravity, by applying to the mouth of a pipe, or to the
open end of an open pipe, one or more moveable shades, which the performer
by means of a pedal or pedals, or by a stop or stops for the hand, or in any other
way, may be enabled to remove from or bring to the mouth or open end of the
pipe at his pleasure. These shades are made of thin plates of lead or pipe
metal, such as is used in the manufacture of metal pipes (thicker or thinner
according to the size of the shade), or of other convenient materials. The
shades bear a different proportion to the mouths or open ends of the pipes to
which they belong, according to the degree of alteration intended to be pro-
duced on the pitch of the pipes. When it is intended to alter the pitch of a
pipe by what is called the enharmonic fourth of a tone, or the diesis in a
tempered system, when the shade is of such size as to cover the whole length
of the mouth (across the pipe), rising about as much above the upper lip, or of
such size as to cover the whole open end of the pipe, and one such shade only
is applied to each pipe, or the pitch of an open pipe may be altered the diesis, by
means of one shade at the mouth to alter it in part and another shade at the
open end, to alter the pitch as much more as requisite. This is chiefly useful
when, as sometimes happens, the pipe cannot well bear to be altered, the whole
diesis at the mouth or open end, or in the case of open wooden pipes, which
are tuned by means of a fixed shade at the open end. When it is intended
that cach shade should alter the pitch by what is called comma, being the
difference between the major and minor tones, in a system of perfect intonation,
then there may be two shades to the mouth or open end of each pipe, and the
one shade is made to cover a little more than the half of the mouth (across the
pipe), but rising as much as the formerly described shade above the upper lip,
or a little more than the half of the open end of the pipe, and the second shade
is made to cover the remainder of the mouth or open end; or in the case of an
open pipe, one shale may be applied to the mouth to alter its pitch comma,
and another shade may be applied to the open end to alter it another comma,

page_text: For the convenience of being removed from or brought to the pipe, the shades
are fixed on rollers or cylinders of wood, or other proper materials, moving on
pivots. For the purpose of attaching the shades to the rollers, each shade
may be soldered to a piece of tinned wire, or brass wire, which piece of wire
may be screwed into the roller, or the shade may be attached to the roller in
any other convenient way. When two shades are applied to the mouth or
open end of one pipe, or when, in a range of pipes, the shades of some are
upon different rollers from those of others, then the rollers may be arranged one
above another; the wire or stalk, by which the shade is attached on the lower
roller, bending round the other roller or rollers, so as to apply the shade close
enough to the mouth or open end of the pipe to which it belongs, or where
convenient, one or more rollers may be placed on one side, and the others on
the other side of a range of pipes. This description is illustrated in the follow-
ing Figures:No. 1st, Fig. 1 shews two pipes shaded at the mouth, each
with the single shade, to alter the pitch by diesis; a, a, a, a, the mouths of
the pipes; b, b, b, b, the shades represented transparent that the mouths may
be seen; c, c, the wires or stalks by which the shades are attached to the
rollers; d, d, the stalk attached to the lower roller, bending round the roller
above it; e, e, supports for the pivots of the rollers, one at each end of the
range of pipes. Fig. 2 and 3 are side views of a pipe shaded at the mouth,
to shew the position of the shades when
references being the same as in Fig. 1.
the open end; a, a, a, a, the open ends; b, b, the shades; c, c, the stalks, which
attach the shades to the rollers d, d, which are represented sloping to correspond
with the tops of the pipes. The shade attached to the upper roller is repre-
sented as close applied to the open end of the pipe, and that on the lower roller
as removed from the pipe to which it belongs. Fig. 5th is a bird's eye view of
the same. Fig. 6th is a pipe having two shades at the mouth, each to alter the
pitch comma. Fig. 7th is a pipe with two shades at the top or open end, the
one shade being close applied and the other removed. Fig. 8th is a bird's-eye
view of the same; the references in these Figures will be understood from
what has been already said. The use of these moveable shades is, that by
means of them organs may be constructed with more complete scales than those
in ordinary use, without so great a multiplication of pipes as without this
Invention would be necessary. And whereas, from the ordinary construction
of the bellows, those, at least, which rise on four ribs of equal breadth at each
side and each end, they do not blow with an uniform force, but with less force
when full, and with a continually encreasing force as the top sinks, and vice
versa.
close applied and when removed, the
Fig. 4th shews two pipes shaded at

page_text: We, the said Henry Liston and Charles Broughton, declare that our Inven-
tion consists, secondly, in a regulator, which renders the blast of the bellows
perfectly equable. This regulator is shewn No II., Fig. 1st. It consists of a
spiral piece of wood (or other proper material) a 1, 2, 3, of about half an inch
in thickness, more or less, according to the size of the machine, and of a pulley
6 1, 2, 3, of similar thickness, fastened to the spiral. This machine turns on
a pin at the common centre of the spiral and pulley c. The string d, d, d, is
fastened to the pulley b 1, 2, 3, at e, and being wound round it passes under a
small pulley at f, and is fastened to the top board of the bellows at g, at about
an equal distance from either end. Another string h, h, fastened to the string
d, d, d, passes under a pulley at i, goes under the bellows and a similar pulley
on the other side, and is fastened to the opposite side of the top board, that
when these strings act on it, they may pull both sides equally. These three
small pulleys may run in one piece of wood, as shewn, Fig. 2d, which being
placed under the bellows, may be fastened to the frame of the organ. The
weight or counterpoise is suspended by a string m at the centre of the spiral,
when the bellows are quite empty; when, therefore, the bellows begin to
rise, the strings d, d, d, h, h, are drawn so as to turn the pulley, and conse-
quently the spiral in the direction b 1, 2, 3, and then the string m is taken
upon the edge of the spiral, which is grooved to receive it. Thus, as the
bellows are gradually losing force, the counterpoise 7 is gradually gaining power
by the increasing radius of the spiral on which it acts. If the bellows rise so
much as to cause the pulley and spiral make an entire revolution, the weight
will be in the position A, acting on the extremity of the spiral, and as the bellows
sink, the spiral, turning in the opposite direction, will gradually unwind the
string, so that the counterpoise will act on a radius continually decreasing as
the force of the bellows is encreasing; the accuracy with which the regulator
will equalise the force of the blast depends on three circumstances, viz, the
form of the spiral, the size of the pulley 61, 2, 3, and the weight of the
counterpoise 7. The spiral curve is to be formed by the following rule:-
Describe a circle of any convenient diameter, and, supposing the whole circum-
ference to represent the line of the greatest angle, which the ribs of the bellows
make with the bottom or top boards; assume any point, and from thence
divide the circumference into segments (always measured from the same point),
respectively proportional to the lines of the angles, up to that greatest angle.
It will be sufficiently accurate to take the lines of the first five degrees; thence
the lines of each half degree, up to 15°, and thence to the greatest angle (the
entire revolution), each quarter degree draw radii to all these points. Then,
from the centre of the circle measure off each radius proportionally to the secant.

page_text: of its respective angle, and from this point draw a perpendicular to the radius;
these perpendiculars, by their mutual intersections, will, form an irregular
polygon, approaching to the curve required; the scale of equal parts, by which
the radii are measured proportionally off to the secants of the angles, will be
greater or smaller; according to the size of the bellows to be regulated. For a
chamber organ of four or five stops, the secant of the greatest angle may be about
ten inches. For large bellows it may be considerably greater, otherwise the
weight or counterpoise might be inconveniently great. The size of the pulley
is to be such that its circumference shall be exactly equal to the rise of the
bellows, when the ribs make with the bottom or top boards the greatest angle,
for which the spiral is made. The size of the pulley will, therefore, cæteris
paribus, depend on the breadth of the ribs. Thus, if the breadth of the ribs
be five inches, the circumference of the pulley should be equal to twice the size
of the greatest angle, as put down in the ordinary tables of sines, tangents, &c.
calling the first figure in the table incles, and the rest decimals of an inch. If
the ribs be less or more than five incles, the circumference of the pulley will
be found, from the tabular sine, by a statement in the rule of three, vizt, as
five is to the tabular sine, so is the rib to a fourth proportional, which being
doubled, is the circumference required. The weight of the counterpoise will
most easily be found by experiment. If it be too little it will correct the evil
in part, but not entirely; the bellows will, therefore, still gain some force as they
fall. If, again, the counterpoise be too great, the bellows will have most force
when full, and will gradually lose force as they fall.
In testimony whereof, I have hereunto set my hand and seal, at Edin-
burgh, North Britain, this Twenty-first day of August, One thousand
eight hundred and ten, and of the reign of our Sovereign Lord George
the Third, of the United Kingdom of Great Britain and Ireland, King,
Defender of the Faith, &c., the fiftieth year.

page_text: deliver the above writ of Specification, and that the names of Thomas Peat
and Andrew Reid, set or subscribed thereto, are the proper handwriting of
the deponents respectively.