CERTAIN IMPROVEMENTS IN THE CONSTRUCTING AND MAKING OF MUSICAL INSTRUMENTS, WHICH AFFORD THEIR TONES BY FRICTION APPLIED TO METALLIC SUBSTANCES
Year: 1812

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
GROLL, of Leicester Place, Leicester Square, in the Parish of Saint Martin in
the Fields, in the County of Middlesex, do send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-eighth day of
January, in the fifty-second year of His reign, did give and grant unto me, the
said Charles Groll, my executors, administrators, and assigns, His special
licence, full power, sole priviledge and authority, that I, the said Charles
Groll, my executors, administrators, and assigns, 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 IN THE CONSTRUCTING AND MAKING OF MUSICAL
INSTRUMENTS, WHICH AFFORD THEIR TONES BY FRICTION APPLIED TO METALLIC
SUBSTANCES;" in which Letters Patent there is contained a proviso, obliging
me, the said Charles Groll, under my hand and seal, to cause a particular
description or explanation or communication of the said discovery or Invention,
and in what manner the same is to be used, to be enrolled in His Majesty's
High Court of Chancery within six months next and immediately 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.
NOW KNOW YE, that in compliance with the said proviso, I, the
said Charles Groll, do hereby declare that the nature of my said Invention,

page_text: ner of performing the same, are particularly described and
manner following, that is to say:-
se parts of the said musical instruments, in or by which the
on or vibrations of each distint note or tone or of the several
or tones is or are severally and respectively produced, of the
the Drawing, Fig. I, with the changes and variations herein-
d, and of any sonoroses metal, but I usually employ brass or
ed with a small portion of tin; and I do call the same double
practice the number of bars may consist of three or more,
ced opposite to each other, or of two or more pairs or setts
connected or constructed together, or formed by insertion of a
piece or pieces between bars of much greater length than would
afford the intended note. And I do further declare that one of
dvantages of the said combination of bars is to afford a good
the most acute notes may be produced with equal facility by
ame description. In the said Drawing are shewn two bars,
branches, or plates, distant from each other about one-eighth of
in inch, and solidly connected at their extremities by casting
or fastening the whole together, or by cutting the slit or aper-
ture in a solid piece of metal, or by soldering or uniting the
parts together in any good, firm, and workmanlike manner.
The depth of the said double bars, as seen in Fig. 2, may be
various, according to the choice of the maker, but I usually
make them about three or two eighth parts of an inch deep.
The thickness of each bar, as shewn in Fig. 1, and also the
ength of the slit, may likewise be varied to a great extent;
but it is essential that all the several bars so connected together,
n order to produce any determinate note, should be equal and
similar to each other, because they would afford no musical
sound if in any considerable degree unequal or dissimilar to
each other. And, further, with regard to the said thickness of
bar and length of slit, I do declare that the pitch or gravity and
acuteness of the tone afforded by any sett of the same, does
depend upon the said particulars, and that the tone will be
lower or more grave the thinner the bars and the longer the
slit. And, accordingly, that I do originally make my setts
h dimensions as by previous trial with the metallic material
paid to the intended size and form of the instrument to be
do find convenient and suitable, and that I do afterwards

page_text: tone my said double bars by reducing the thickness thereof or lengthening the
slit, if too sharp, or by inserting a small piece of metal or other material into
the slit (in the situation which will be indicated by trial), if too flat. And,
farther, with regard to some of the actual sizes or dimensions by which certain
precise tones may be afforded, I do find that allowing for change of dimensions
by the operation of tuning as aforesaid, the following dimensions do answer
very well-If the bar be one-eighth of an inch thick and the slit twenty
inches long (and wide enough to prevent the vibrating bars from touching and
jarring), the note will be three octaves below the middle C, which is placed
between the bass and the treble cliffs; and if the slit be sixteen inches long
the note will be two octaves below the said middle C; and if the slit be twelve
inches, the note will be one octave below the said middle C; and if the slit be
nine inches, the note will be the said middle C; and if the slit be six inches,
the note will be one octave above the middle C; and if the slit be four inches,
the note will be two octaves above the said middle C; and if the slit be three
inches, the note will be three octaves above the said middle C. And from the
said dimensions which are suited to metal of moderate hardness and elasticity,
it will be asy to ascertain the length of slit for the intermediate notes, which
will not considerably differ from an arithmetacal series interposed between
them. And I do farther declare that in order to bring out and augment the
tone, it is necessary to fix or apply one or both the extremities or connecting
parts of the said bars to a sounding board, formed or constructed upon the
principles which are well known to workmen, and in general use. And
farther, that with regard to the production of sound by exciting vibrations in
the said bars, I do effect and accomplish the same by means of any of the
well-known instruments which excite sound by continued friction upon the
sounding material, namely, such instruments as the violin bow or the revolving
catgut or string, or the endless webb or ribband of horsehair or other fibrous
material, or the wheel or cylinder acting by the friction of its face, in or upon
all which it is usual to apply rosin, or colophony, or some resinous matter, for
the purpose of encreasing and modifying the friction. And I do apply the
said friction or bowing against or upon one of the said bars, or both, or in
preference, for the sake of convenience, against a small stem or stems, stud or
studs, protuberance or protuberances, fixed to or proceeding from one of the
said bars or from both seperately, or otherwise. And I do make use of
wheels, cylinders, treadles, and other gear or apparatus to move the part
which acts by friction, such as have been heretofore used in keyed or other
instruments wherein the sound was produced by bowing or continued friction,
and I do cause the sound to be produced by the intervention and use of keys,

page_text: levers, and apparatus, sufficiently well-known, and which serve by the absolute
or relative motion of the said bowing or rubbing parts, or of the said bar itself,
or the protuberance or protuberances therefrom, or of all or either of the same,
to bring the parts into action for each particular note. And whereas the
means or methods of producing the notes in key'd instruments operating by an
hair webb or ribband or by the other apparatus herein-before mentioned, upon
strings and other sonorous bodies, are in general use, and do not constitute
any part of my present improvements, I do declare that I avail myself of the
said means or methods, and do therefore consider it to be unnecessary to
describe the same. And farther, that the several forms and constructions of
musical, instruments in which my said improvements shall or may be adopted,
will be various, according to the choice or intention of the maker, and are
sufficiently obvious in themselves to any intelligent manufacturer without
farther explanation.
In witness whereof, I, the said Charles Groll, have hereunto set my
hand and seal, this Twenty-seventh day of July, in the year of our
JAS. STEPHEN.
AND BE IT REMEMBERED, that on the same Twenty-seventh day of
July, in the year above mentioned, the aforesaid Charles Groll came before
our Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and everything therein contained, in form above written.
And also the Specification aforesaid was stamped according to the tenor of the
Statute in that case made and provided.
Inrolled the same Twenty-seventh day of July, in the year above
written.