CERTAIN IMPROVEMENTS UPON HARPS
Year: 1807

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
GRÖLL, of Leicester Fields, in the Parish of Saint Martin, and City of West-
minster, send greeting.
WHEREAS His most Excellent Majesty King George the Third did,
by His Letters Patent under the Great Seal of that part of the United
Kingdom called England, bearing date at Westminster, the Thirteenth day of
July, in the forty-seventh year of His reign, give and grant unto me, the
said Charles Gröll, His special licence that I, the said Charles Gröll,
during the term of years therein mentioned, should and lawfully might use.
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "CERTAIN IMPROVEMENTS UPON HARPS;" in which
said Letters Patent there is contained a proviso obliging me, the said Charles
Gröll, by an instrument in writing under my hand and seal, to cause a par-
ticular description of the nature of my said Invention, and in what manner
the same is to be performed, to be enrolled in His Majesty's High Court of
Chancery within six calendar months after the date of the said recited
Letters Patent, as in and by the same, relation being thereunto had) may
more fully and at large appear.

page_text: NOW. KNOW YE, that in compliance with the said proviso, I, the said
Charles Gröll, do hereby declare that my said Invention is of the description
following, and plan hereunto annexed, viz. :—
.
First, instead of raising each of the strings of the harp, through the interval
of a semitone (whenever required); by means of one single order, rank, or
arrangement of divisions, by means of forks, hooks, rings, or similar well-known
contrivances, (namely, one of the said forks, hooks, rings, or contrivances being
applied and adapted to each string,) I do apply, adapt, and use two such orders,
ranks, or arrangements of divisions, as herein-after is more particularly set
forth, for the purpose of raising each of the said strings (whenever required)
through-the-intervals of two semitones. And I do also cause the intended
effect of the said divisions to be produced at pleasure by fit-and-appropriate
machinery adapted to the pieces which constitute the said orders, ranks, or
arrangements of divisions, and communicating with certain pedals, which is
likewise herein-after more particularly set forth. And the construction of the
first part of my said Invention which I am now describing is shewn in the.
Drawings hereunto annexed.
Figures 1, and 2, and 3 represent so much of the harp as may be
sufficient to exhibit and explain this part of my said Invention as applied to
one single string. 2, 2, represents the string proceeding downwards from the
turning pin and over the bridge pin R, and between the two forks or other
occasional stopping pieces A, B. The distance between A and R is so adjusted
that whenever-A, by the usual quarter turn on its axis, is made to stop or,
bind the string, it shall cause the disengaged or lower part of the said
string to afford a tone which shall be half a note higher or more sharp than
before; and the distance between B and R is so adjusted that whenever B, by
the usual quarter turn on its axis is made to stop or bind the string, it shall
cause the then disengaged or lower part of the said string to afford a tone
which shall be two semitones or half notes higher or more sharp than the tone
afforded by the open string. The darker shaded parts of the ground or
surface in the Figures 1, 2, and 3 are supposed to have the front plate removed,
in order to shew the interior mechanism by which the pieces A and B are.
worked. E is a three-tailed piece, moveable on its centre E, and giving the
needful motion to A by a communication from its tail C. F is another piece
moveable on its centre F, and performing the like office with regard to B, by
means of a communication from its tail D. I is a piece moveable on its
centre I, and giving motion to E and F by means of its tails G and H, which.
to prevent friction are made to terminate in small rollers. S is a wire or
suitable rod of communication which is attached beneath to the treadle.

page_text: Fig. 4, Fig. 5, or Fig. 6, from each correspondent system, Fig. 1, Fig. 2, or
Fig. 3, immediately above. L, K, M is a reaction spring fixed at L, and at-
tached to the piece I by its extremity M, so that it brings the piece I back to the
position exhibited in Fig. 1, whenever the action of the treadle is not exerted
upon S. And lastly, as to the parts of the mechanism, there are two gentle springs
within the forked parts of E and F, against which the rollers of I do act, and
keep the pieces A and B steadily in their respective situations, when not
required to act upon the spring. The action or effect is as follows:-In Fig. 1
the whole spring is at liberty to vibrate, and the whole of the apparatus,
together with the pedal F 4, possesses the situations respectively described in
the Drawings. But when the pedal N, Fig. 4, becomes depressed to the situa-
tion shewn in Fig. 5, the wire S draws I into its first position of action, during
which the roller H runs along the spring of F without disturbing that piece
or its fork B, and at the same time the roller G acts against a snail fall or
inclined plane in E, so as to turn that piece, and throw the fork A into action
upon the string, which thus becomes raised one semitone. And again, when the
pedal N, Fig. 4, or 5, becomes farther depressed to the situation shewn in
Fig. 6, the wire S draws I into its second position of action, during which the
roller G runs along a circular part of the tail of E without producing any farther
motion in that piece, and at the same time the roller H acts upon the opposite
tail of F so as to turn that piece, and throw the fork B into action upon the
string, which then becomes raised two semitones, or one whole note. And
finally I do (as is usually done in the apparatus in harps where a change of
one semitone on each string is produced) connect all the apparatus belonging
to the several strings of the same denomination, or cach of the respective
series of octaves together, so that whenever a change shall be produced by the
action of one of the pedals in the note or tone of any one string the like change
shall be produced in all the strings of the same denomination. And I do
dispose my said apparatus in a workmanlike manner adapted to the spaces
into which the same is to be disposed, and sufficiently clear in its parts with
regard to each other that all the intended effects may be produced without any
undue interference of one part with any other.
Secondly, in order that the strings of the harp may be tuned with more
certainty and precision, and may continue longer in tune, I fix upon the pin
which is to receive the string a racked wheel, into which I cause an endless
screw to work, and produce a slow, steady, and firm motion.
represented in Fig. 7, 8, and 9.
These parts are
Thirdly and lastly, in order that the forks A and B may be placed and
securely fixed on their axis so as to hold upon and stop the spring in the exact

page_text: position required. 1 make a right and left hand screw upon the axis or sterm
C, Fig. 10, 11, and 12, and upon the first of the said screws f I screw the
fork itself, and when the said fork hath been duly placed 1 do then turn nutt
or index so as firmly to bind against the face of the said fork or piece, and
thereby secure the same in its place.
In witness whercof I, the said Charles Gröll, have hereunto set my hand
and seal, this Eleventh day of January, in the year of our Lord
One thousand eight hundred and eight.