Patent of 1857 : "LETTERS PATENT
to George Crawford, of Edinburgh, in the County of Mid Lothian, North
Britain, Music Seller, for the Invention of “IMPROVEMENTS IN
PIANOFORTES."
Sealed the 3rd September 1857, and dated the 14th May 1857.
PROVISIONAL SPECIFICATION left by the said George Crawford at the Office
of the Commissioners of Patents, with his Petition, on the 14th May
1857.
I, GEORGE CRAWFORD, of Edinburgh, in the County of Mid Lothian, North
Britain, Music Seller, do hereby declare the nature of the said
Invention for “IMPROVEMENTS IN PIANOFORTES,” to be as follows, that is
to say :
This Invention relates to various modifications of the details of
pianofortes, for the purpose of producing a general improvement in the
tone and effect of the instrument. According to one portion of these
improvements, the part of the pianoforte technically known as the “rest
bridge” is made of glass, so as to secure a superior purity of tone. The
sounding board has upon it a double bridge with a suspension tube, the
bridge being indented with bone or ivory instead of small pins in order
to conduct more tone or vibration from the sounding board. The
suspension tube is screwed to the sounding board between the Crawford's
Improvements in Pianofortes. two bridges, for the strings to pass
underneath, causing a transverse bearing, which takes the strain from
the sounding board and allows of a free vibration.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed
by the said George Crawford in the Great Seal Patent Office on the
13th November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE CRAWFORD, of
Edinburgh, in the County of Mid Lothian, North Britain, Music Seller,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of May, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said George Crawford, Her special license that I, the said
George Crawford, my executors, administrators, and assigns, or such
others as I, the said George Crawford, my 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 therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for “IMPROVEMENTS IN 20 PIANOFORTES," upon the
condition (amongst others) that I, the said George Crawford, by an
instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Crawford, do hereby declare the
nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement in writing, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say :
My said Invention relates to various modifications of the details of
pianofortes, for the purpose of producing a general improvement in the
tone and effect of the instrument.
According to one portion of these improvements, the part of the
pianoforte technically known as the “rest bridge” is made of glass,
so as to secure a superior purity of tone. The sounding board has upon
it a double bridge with a suspension tube, the bridge being indented
with bone or ivory instead of small pins in order to conduct more tone
or vibration from the sounding
board. The suspension tube, if screwed to the sounding board between the
two bridges for the string to pass underneath, causing a transverse
bearing, which takes the strain from the sounding board and allows of a
free vibration.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the several illustrative Figures on the
explanatory Sheet of Drawings which I have hereunto appended for the
purpose of showing certain modifications under which my improvements may be judiciously
carried out in practice.
English Patents of Inventions, Specifications,
1857, p. 10/42
Figure 1 on my accompanying Sheet of Drawings is a sectional elevation
of the internal portion of a pianoforte, showing the sounding board and
“ rest" as arranged with one modification of my improvements applied
thereto; Figure 2 is a transverse vertical section, taken at right
angles to Figure 1; and Figure 3 is a vertical section of a portion of
the details, drawn to a larger scale than Figures 1 and 2, to show more
clearly the arrangement of the tubular bridge herein-after described.
The first part of my said Invention has reference to what is technically
known as the “rest bridge;" in this modification this part of the
instrument is constructed of glass, or other material more resonant than
wood, or a combination of wood and metal, which materials have hitherto
been used for the purpose. The improved “ rest bridge,” as shown in my
illustrative Drawing, is made of a series of pieces of glass, the upper
surface of which, or that upon which the strings rest, being either of a
convex or concave form, or it may be made with a flattened ridge, and
sloping or angular sides.
The several pieces of glass intended to
form the “rest þridge” are placed on the rest plank A, and the pieces of
glass B are arranged or placed end to end, and curved or otherwise
disposed so as to form the figure required for the support of the
strings, as they vary in length, and are held in position by the
downward pressure of the strings. The strings of the instrument pass in
the first place from their “ hitch” pins C, beneath the tubular bridge
D, which is fastened to a wooden stay at the back of the sounding board
E. The details of this bridge are more clearly shown in the enlarged
sectional view, Figure 3.
It consists in this modification of the
duplex pieces of wood D, in which are
inserted pieces of bone or ivory F; these pieces of ivory are either
notched or plain, and receive the strings G, which rest partly upon the
ivory and partly on the bridge D. The strings are passed over the first
series of the pieces F, and under the tube H; this tube is secured to
the sounding board by screws I, which pass through the sounding board E,
and into a strengthening piece of hard wood J, at the back of the
sounding board.
A modification of the arrangement of this part of the
improvements is obtained by making the bridge D in one piece instead of
in two, as shown in the sectional view, Figure 3, the tube H being
fitted in a hollow or indentation in the bridge.
The strings G pass under the tube H, and
over the second series of ivory supports F, whence they are carried over
the rest bridge B, beyond which they are passed through studs K, and are
finally secured to the rest pins L. Instead of making the rest bridge of
glass, as herein-before described, it may be constructed of china,
earthenware, particular kinds of stone, porcelain, or other vitrified
substances, or other suitable materials more
resonant than wood, or a combination of wood and metal.
Another modification of my improvements consists in the use and
application of double sounding boards in pianofortes, in order to
increase the volume of sound from the instrument. The rest plank above
the duplex sounding boards may be supported by means of metal tubes,
fitted between the two sounding boards, and wooden bracings may be
fitted behind the sounding boards to support the “rest plank."
Pianofortes made according to these
improvements possess great brilliancy of tone, and give out a volume of
sound greatly superior to those of the ordinary construction; this
superiority of tone and
power being derived from the use of the crystal or other similar
resonant body, and from the strain being removed from the sounding board
by the transverse bearing obtained by the suspension tube.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or
restrict myself to the precise details or arrangements which I have had
occasion to describe or refer to, as many variations may be made
therefrom without deviating from the principles or main features of my
Invention; but what I consider to be novel and original, and therefore
claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,–
First, the general arrangement and construction of pianofortes, as
hereinbefore described.
Second, the use and application of glass, china, earthenware, stone, or
composition of a generally similar character in the manufacture or
construction of “rest bridges" for pianofortes, as herein-before
described.
Third, the use and application of metal tubes to the bridges of
pianofortes, in which arrangement the strings are supported upon pieces
of ivory, bone, or other suitable material forming the apices of the
bridge, the combination of Crawford's Improvements in Pianofortes. the
parts tending to take the strain off the sounding board, and increasing
the vibration of the instrument, as herein-before described.
Fourth, the use and application in pianofortes of a secondary sounding
board, in order to increase the volume of sound imparted by the
instrument, as herein-before described.
In witness whereof, I, the said George Crawford, have hereunto set my
hand and seal, this Tenth day of November, One thousand eight hundred
and fifty-seven. GEORGE CRAWFORD. (L.s.)"
English Patents of Inventions, Specifications,
1857, p. 10
