CERTAIN IMPROVEMENTS ON PIANOFORTES
Year: 1829

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
STEWART, of George Street, Euston Square, in the County of Middlesex,
Pianoforte Maker, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of. Great Britain, bearing date
at Westminster, the Second day of November, in the tenth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
James Stewart, His special licence that I, the said James Stewart, my
executors, administrators, and assigns, or such others as I, the said James
Stewart, my executors, administrators, or assigns, should at any time agree with,
and no others, from time to time and at all times during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "CERTAIN IMPROVEMENTS ON PIANOFORTES;" in which said Letters Patent is
contained a proviso obliging me, the said James Stewart, by an instrument
in writing under my hand and seal, particularly to describe and ascertain
the nature of my said.Invention, and in what manner the same is to be per-
formed, and to cause the same to be.enrolled in His said Majesty's. High Court
of Chancery within two calendar months next and immediately after the date
of the said recited Letters Patent, as in and by the same, reference being
thereunto had, will more fully and at large appear..
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Stewart, do declare that the nature of my said Invention is ascertained
as follows (that is to sav).

page_text: DESCRIPTION OF THE DRAWING.
Number 1.-The part from the top to the bottom of the Drawing coloured
blue represents one side of the frame which supports the machanism of the
instrument commonly called the action frame.
.
Number 2.-The hammer rail fixed in the front to the action from No. 1.
The part, coloured yellow, on the upper extremity of this rail, represents the
brass plates in which the centre of the hammer is inserted. This hammer
rail, so far as is now explained, is such as is in general use, and is commonly
called the brass rail, although its main substance is wood, with brass only on
the upper part.
Number 3. Another wooden rail secured to the action frame Number 1.
The bottom of this is guarded with thick cloth, to receive the end of the key
Number 4, when it is raised. This is commonly called the back touch.
Number 5. Another wooden rail is fixed to the action frame Number 1,
on the back part, or that part which faces the performer when sitting at the
instrument.
Number 6. The part coloured yellow, and fixed by screws to the upper
part of the rail.
'
Number 5 represents two brass plates, formed in the same way as those
of the hammer rail Number 2. Those plates receive the wire on which
the centre of the horizontal lever Number 7 works.
Number 8 is that part of a cabinet pianoforte commonly called the sticker.
Its length is regulated by the elevation of the instrument to which it is applied,
as cabinet pianofortes are made of various heights. It is a slender piece of light
wood, which in cabinet pianofortes of the common construction is hinged with
leather to a projection from the lower part of the hammer block Number 9,
but in the construction described by the Drawing is hinged with leather to
the lower part of the horizontal lever Number 7. The lower extremity of
this sticker is inserted into the key.
Number 10 is a piece of wood fixed on the horizontal lever Number 7,
divided on the upper part, and having a piece of wire passed through it, which
is the center on which the lower extremity of the upright lever Number 11
works.
Number 12 is a metal spring fixed on the piece of wood Number 10, and
acting on the back part of the lever Number 11, so as to keep it steady under s
the notch in the hammer block Number 9, which notch is guarded with
leather to prevent noise..
..
Number 13 is a thin piece of wood secured on to the back part of the hammer

page_text: rail Number 2, having a projection at the upper end, guarded with leather or
cloth, and acting on the inclined plane in front of the lever Number 11. When
the key Number 14 is pressed down, so as to liberate the lever Number 11
from the notch in the hammer block Number 9, when the hammer head
(Number 15) has been propelled towards the string (Number 16) a sufficient
distance to give the string a clear and free stroke, that is, that the lever should
quit the notch of the hammer block when the head of the hammer is about
one-eighth of an inch from the string.
Number 17 is a screw passing through the hammer rail against the piece
of wood Number 13, to regulate the position of the latter on the inclined
plane of the lever Number 11, so to make that lever quit the notch of the
hammer when the hammer has reached the proper height on pressing down
the key.
Number 18 is a piece of wood having a shaft passing into the hammer
block (Number 9), which by its weight brings the hammer back after it has
struck the string towards its original positions, and in conjunction with Number
.19 arrests the hammer in its descent, and prevents its reverberating against the
string until it has received a renewed impulse from the percussion of the
key by the finger. This part, Number 18, is usually called the hammer
balance.
No. 19 is that part of the mechanism which is technically termed a check.
Its upper part, which comes when in action in contact with Number 18, for
the purpose of arresting the hammer in its descent, is formed either of wood
covered with leather or of leather alone, and is fixed on a wire which passes
down and is secured in the horizontal lever Number 7.
Number 20 is a wooden rail secured to the back part of the action frame
Number 1, and guarded with cloth on which the hammer shaft rests, when
the hammer is in a quiescent position.
Number 21 is a triangular piece of wood fixed on the horizontal lever
Number 7, covered with leather, and forming a leather hinge by junction with
the piece of wood Number 22, into which a piece of wire, Number 23, is
screwed, which wire, Number 23, communicates when the key Number 14 is
pressed down by the finger to the damper lever Number 24, and raises the
damper Number 25 from off the string.
Number 26 is a piece of wood fixed on to the side of the case of the
instrument, and joined to the damper lever Number 24 by a leather
binge.
Number 27 is a piece of wood secured to the action frame Number 1, and
perforated with holes lined with cloth, through which the damper wire