IMPROVEMENTS IN DESKS FOR USE IN RETOUCHING PHOTO- GRAPHIC NEGATIVES
Year: 1876

page_text: LETTERS PATENT to Frederic Thomas Burrows and Joseph Dufais Colton,
both of York Place, Portman Square, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN DESKS FOR USE IN RETOUCHING PHOTO-
GRAPHIC NEGATIVES.”
Sealed the 17th November 1876, and dated the 30th May 1876.
PROVISIONAL SPECIFICATION left by the said Frederic Thomas Burrows
and Joseph Dufais Colton at the Office of the Commissioners of Patents on the
30th May 1876.
FREDERIC THOMAS BURROWS and JOSEPH DUFAIS COLTON, both of York Place,
Portman Square, in the County of Middlesex. "IMPROVEMENTS IN DESKS FOR USE
IN RETOUCHING PHOTOGRAPHIC NEGATIVES."
Our Invention relates to desks for use in retouching photographic negatives, and
the improvements comprise-
First. A series of screens of varying degrees of transparency whereby the
operator is enabled to regulate his labor according to the amount of care intended
to be bestowed on the negative, the screen serving to temporarily conceal more or
less, according to its degree of transparency, the minor imperfections in the negative
leaving only the grosser defects visible, so that the attention of the operator is
confined to the faults which it is desired to remove, and is not distracted by the
small imperfections which, the price being low or from some other cause, it is not
worth while to correct. A mechanical selection is thus made which is a great
assistance to the operator, who is, moreover, enabled to judge exactly the effect
which his work will produce upon the finished picture. The screens consist of
plates of glass of different degrees of density fitted in openings in a disc pivoted
to the under side of the carrier on which the negative is mounted, in such a position
that any one of the screens can be quickly made to coincide with the opening in the
rotating carrier over which the negative is fixed.
Secondly. The negative is secured by clamps in a circular carrier fitted to rotate
in the desk so that the operator can vary the position of the negative to suit his
convenience as the work proceeds without having to remove the negative or to
make use of any portable frames or appliances, as with desks now in use. The
clamps are furnished on the under side and are fitted with india-rubber cushions to
ensure immunity from the risk of breaking the negative when the clamp screw's
are tightened up, and the clamps are fitted to slide in dovetailed grooves so as to
be readily adjusted to the size of the negative.
Price lid.1

page_text: Thirdly. In the employment of a concave reflector mounted upon adjustable
supports behind the desk so as to be readily adapted to suit the direction of the
light. With this reflector may be combined a lamp for night work, a plate of
optical violet glass being in this case fitted in the revolving carrier to stop the
yellow rays proceeding from the lamp above referred to.
Fourth. The magnifier is so mounted upon a fixed standard at the left hand that
it can be readily adjusted in any desired position to suit the sight without inter-
fering with the right arm of the operator. Another advantage is that the magnifier
being mounted on a fixed support it is perfectly steady, and the operator's sight
is not impaired by the constantly changing focus, as is the case when the magnifier
is held in the hand.
Another improvement consists in a pencil sharpener fitted to slide within the
desk, and consisting of a block on which a sheet of emery paper or other suitable
abrading substance is stretched or clamped by a metal frame. This block draws
out from the case in a convenient position at one side, and is retained by a spring
which ensures its rigidity and permits of the emery paper or other material used
being renewed from time to time.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Frederic Thomas Burrows and Joseph Dufais Colton in the Great Scal
Patent Office on the 30th November 1876.
FREDERIC THOMAS BURROWS and JOSEPH DUFAIS COLTON, both of York Place,
Portman Square, in the County of Middlesex. "IMPROVEMENTS IN DESKS FOR USE
IN RETOUCHING PHOTOGRAPHIC NEGATIVES."
Our Invention relates to desks for use in retouching photographic negatives, and
the improvements comprise-
First. A series of screens of varying degrees of transparency whereby the
operator is enabled to regulate his labor according to the amount of care intended
to be bestowed on the negative, the screen serving to temporarily conceal more or
less, according to its degree of transparency, the minor imperfections in the negative,
leaving only the grosser defects visible, so that the attention of the operator is
confined to the faults which it is desired to remove, and is not distracted by the
Sinall imperfections which, the price being low or from some other cause, it is not
worth while to correct. A mechanical selection is thus made, which is a great
assistance to the operator, who is, moreover, enabled to judge exactly the effect
which his work will produce upon the finished picture. The screens consist of
plates of glass of different degrees of density, fitted in openings in a desk pivoted
to the under side of the carrier on which the negative is mounted, in such a position
that any one of the screens can be quickly made to coincide with the opening in
the rotating carrier over which the negative is fixed.
Secondly. The negative is secured by clamps in a circular carrier fitted to rotate
in the desk, so that the operator can turn the negative round to suit his convenience
as the work proceeds without having to remove the negative or to make use of any
portable frames or appliances as with desks now in use. The clamps are furnished
with pads of india-rubber or other soft material to avoid risk of breaking the
negative when the clamp screws are tightened up, and the clamps are fitted to slide
in dovetailed grooves so as to be readily adjusted to the size of the negative.
Thirdly. In the employment of a coucave reflector mounted upon adjustable
supports behind the desk so as to be readily adapted to suit the direction of the
light. With this reflector may be combined a lamp for night work, a plate of
optical violet glass being in this case fitted in the revolving carrier to stop the
yellow rays proceeding from the lamp.
Fourth. The magnifier is so mounted upon a fixed standard at the left hand that
it can be readily adjusted in any desired position to suit the sight without inter-
fering with the right arm of the operator. Another advantage is that the magnifier

page_text: being mounted on a fixed support it is perfectly steady, and the operator's sight
is not impaired by the constantly changing focus, as in the case when the magnifier
is held in the hand.
Another improvement consists in a pencil sharpener fitted to slide within the
desk, and consisting of a block on which a sheet of emery paper or other suitable
abrading substance is stretched or clamped by a metal frame. This block draws
out from the case in a convenient position at one side, and is retained by a spring
which ensures its rigidity and permits of the emery paper or other material used
being renewed from time to time.
Figure 1 shows a central section of the improved retouching desk open for use by
daylight. Figure 2 shows a front view of the revolving carrier as fitted in the desk.
Figure 3 represents a back or under side view of the same to show the position
of the disc holding the screens. Figure 4 shows the support for the magnifier, and
Figure 5 the pencil sharpener.
A is the lesk frame hinged at the front to a box or base B, and having a rising
lid Chinged to it, the frame being supported in the open position by struts, as
usual in such desks. D is the carrier for the negative, being a disc with rebated
edges fitted to revolve freely in a corresponding opening in the frame A. E, E, are
metal clamps secured by screw bolts F in metal guides G fixed to the carrier D.
The heads of the bolts are retained beneath the guides, along which the bolts are
movable to adapt the clamps to negatives of different sizes, the clamps being secured
in any desired position by the milled nuts on the bolts. The tips of the clamps
are faced with india-rubber, cork, or cloth to avoid splitting the negative, which
is represented in dotted lines in position over the central opening H in the carrier.
I is a disc laving openings fitted with glass plates K of different degrees of trans-
parency. This disc is mounted to rotate on a pivot l' at the back of the carrier D,
the pivot being at one side of the opening H so that any one of the glass screens K
may be made to coincide with the said opening H by turning round the disc I,
which being attached to the carrier D moves therewith when the latter is turned
round during the progress of the work so that the position of the screen_opposite
the opening H is not disturbed. L is a concave reflector attached to a T-shaped
frame M pivoted between two supports N hinged within the box B. For day work
the reflector is attached to the horizontal part of the frame M, and its position is
regulated by a movable wedge O, as shown in Figure 1, and for night work it is
attached to the central depending leg of the pivoted frame M, a lamp being placed
between the reflector and the carrier, which is raised to the position shown in
dotted lines, Figure 1, and has a plate of optical violet glass fitted in the recess P
over the opening H. R is the magnifying glass mounted on a horizontal telescopic
arin S, provided with a binding screw T, by which the glass may be firmly fixed
in any position or at any angle. This arm S is fitted by a tubular socket and
binding screw U to a vertical standard V firmly fixed at the left-hand side of the
desk, whereby the glass may be adjusted at any desired height. W is a pencil
sharpener fitted to slide in and out at the right-hand side of the box B. "It is
shown separately in plan and longitudinal section in Figure 5. It consists of a
wood block W grooved to receive a metal frame X, by which a sheet of emery
paper or other suitable material is clamped or stretched on the block W. Y are
catches to retain frame W, and Z is a spring by which the sharpener is retained
when drawn out.
Having described the nature of our said Invention, and the manner of performing
the same, we declare that what we claim as the Invention to be protected by the
herein-before in part recited Letters Patent is―
1stly. The employment of a series of screcus or plates of different degrees of trans-
parency interposed between the negative to be retouched and the source of light,
in the manner and for the purpose specified.

page_text: 2ndly. The employment of a revolving carrier fitted in the desk and having the
negative secured directly to it as and for the purpose set forth.
Brdly. The combination with the revolving carrier, constructed and fitted as
described of a disc rotating on a pivot at the back thereof, and containing a series of
yraduated screens, substantially as herein shown and described.
4thly. The employment in a retouching desk of a concave reflector mounted in
adjustable supports, whereby it may be readily adapted for day or night work as
set forth.
5thly. In a retouching desk the magnifier mounted on a telescopic arm supported
on a fixed standard at the left-hand side of the desk, and rendered a fixture in any
desired position by means of binding screws as shown and described.
Gthly. In a retouching desk the pencil sharpener, construsted and fitted to slide
in and out at the right hand side of the base as shown and described.
In witness whereof, I, the said Frederic Thomas Burrows, for myself and on
behalf of the said Joseph Dufais Colton, have hereunto set my hand and
seal, this Thirtieth day of November, in the year of our Lord One thousand
eight hundred and seventy-six.
FREDERIC THOMAS BURROWS. (L.S.)