IMPROVEMENTS IN WRITING AND DRAWING INSTRUMENTS
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
WILLIAM THOMSON, of Leicester Square, in the County of Middlesex, Civil
Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourth day of July
(One thousand eight hundred and forty-nine), in. the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Robert William Thomson, my exors, adññiors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Robert
William Thomson, my exors, admors, and assigns, or such others as I, the
said Robert William Thomson, my exors, admors, 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 "IMPROVEMENTS IN WRITING AND DRAWING INSTRUMENTS;" in
which said Letters Patent is contained a proviso that I, the said Robert
William Thomson, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part 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
Robert William Thomson, do hereby declare that the nature of my said Inven-

page_text: tion, and in what manner the same is performed, are fully described and
ascertained in and by the present Specification thereof, reference being had to
the illustrative Drawings hereunto annexed (that is to say) :-
I make the said instruments wholly or partly of glass, which has the
advantage over the steel of which metallic pens are ordinarily formed, of being
incorrodible by acids, of not being liable to rust, and of wearing much less
rapidly; and I construct them also in such manner that each instrument
serves as its own ink or colour holder, and may be used unintermittingly as
long as there is ink or colour in the holder. Several forms of these instru-
ments are represented in the annexed Drawings, Figure 1.
Figure 1 represents one made wholly of glass. A is the shaft part or
handle; B, a bulb for containing the ink or colour; and C, the writing or
drawing point. In making this instrument I take a piece of glass tube of
suitable length, and with a capillary bore of about the of an inch; I close
it up at one end and then blow it into a bulb of the form shewn in Figure 2,
in the manner usual with glass blowers. The point C is then heated and
drawn off into a curved form suitable for the nib, the width of which
and the opening therein will of course determine the thickness of the
stroke produced by the instrument when in use. The points, instead of
being curved as in the Figures, may be made straight or have any other
shape or curvature given to them which convenience or fancy may dictate.
The nibs are ground on a stone or on a small wheel with emery or diamond
dust; or they may be ground and polished by the modes commonly followed
in the cutting and polishing small articles of glass and precious stones.
bulb or reservoir B is filled with ink or colour by inserting the point in a
quantity of the fluid, applying the mouth to the top and exhausting the air
from the bulb and capillary tube. When the mouth is withdrawn the restored
pressure of the atmosphere prevents the ink from rising in the tube, so that
the instrument may be tossed about or even inverted without any risk of the
ink or colour escaping at the top.
The
Instead of using the mouth to exhaust the instrument an artificial
exhausting piece may be added, such as represented in Figure 3. A is a
short length of tube of larger bore than the entire diameter of the handle A,
and open at both ends. Into one of the ends I insert a collar of vulcanized
india rubber, as shewn at B, Figure 3; I then slip this collar over the handle,
and push it a little way down; on then closing the open end of the tube
A with the thumb or finger, and gradually drawing it off the handle, the air
will be exhausted and the bulb consequently charged with ink or colour.
Another form of exhausting tube is shewn in Figure 3. C is a short tube of

page_text: larger bore than the diameter of the handle (A). B is a piece of vulcanized
caoutchouc tube of a bore smaller than the diameter of the handle, but
expansible by stretching. One end of this caoutchouc tube is drawn over and
secured to the outer end of the tube C, and in the other end of the caoutchouc
tube there is inserted a ferrule D, of metal or glass or other suitable material,
to keep it from doubling under when it is pushed down over the handle of the
pen, as before directed. The air is exhausted and the bulb filled in the same
way as with the exhausting piece, Figure 3.
into the holder A,
The pulling up of
the replenishing of
Figure 4 represents an instrument in which the reservoir B and nib C are
made of glass as before, but the reservoir has a short shank S attached to it,
which fits into an elastic collar of vulcanized caoutchouc D inserted in the end
of a metal handle or holder A. P is a piston, which fits
and is packed at its lower extremity, as indicated at K, K.
this piston serves to produce the exhaustion necessary to
the reservoir B. I is a small aperture in the holder A, which must be closed
with the thumb or finger when the piston is being drawn up, but being left in
all other cases open serves as an escape hole for any air that may be between
the piston and reservoir, and which might otherwise eject by its pressure the
liquid from the reservoir, and serves also to admit air to supply the place of
ink or colour used.
Figure 5 shews a form of instrument suitable for carrying in the pocket.
It is in all respects the same as Figure 4, with the exception that there is
attached to it a metal tube I provided with an air hole a, which, when the
instrument is in use, fits on to the end of the piston P, and forms a convenient
prolongation of the handle, and when the instrument is out of use fits on to
the mouth end, so as to close up the reservoir and prevent any escape of fluid,
in which closed up state it is represented, Fig. 6.
I prefer making the points and nibs of glass, because of the cheapness and
durability of this material, and its not being liable to corrosion or rust, but
they may also be made of any of the precious stones cut and drilled by the
modes in ordinary use among lapidaries, and then attached by cement to
glass bulbs, as shewn at C, Figure 7. I also propose to attach glass and
stone nibs to metal tubes or bulbs. To preserve the nibs from being chipped
a small piece of metal tube may be fitted over the nib, and ground into form
with the glass, as shewn at C, Figure 8; or the nibs may be preserved by.
depositing on them a coating of metal by the electrotyping process, and
ground into shape with the nib.
Figure 9 shews an arrangement for giving elasticity to common metal pen-
holders. A is the metal pen; B, a short tubular holder, into which the pen

page_text: fits, and which has a shank C inserted into and held fast by a vulcanized
india-rubber collar D, inserted within the ordinary holder E.
Figure 10 shews another form of elastic holder. A is the metal pen;
B, a vulcanized caoutchouc plug fastened into the tube or handle C, so that
the lower end of the plug from D to E is free and unattached to the tube C.
The pen A is inserted between the plug B and the tube C. The degree of
mobility of the pen will depend on the tightness with which the plug B is
fitted into the tube. The plug may be made either solid or of a tubular
form.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the making of writing and drawing instruments of glass, shaped or
fashioned as before described.
Second, the making of glass writing and drawing instruments with nibs or
points of any of the precious stones.
Third, the combining in writing and drawing instruments of glass and stone
nibs with metal bulbs or reservoirs.
Fourth, the making of glass writing and drawing instruments with
exhausting pistons, as before described. And,
Fifth, the elastic holders for ordinary metal pens, as before described.
In witness whereof, I, the said Robert William Thomson, have hercunto
set my hand and seal, this 4th day of January, One thousand eight