IMPROVE- MENTS IN PLOTTING' AND "COMPUTING SCALES FOR THE USE OF SUR- VEYORS AND ENGINEERS."
Year: 1866

page_text: LETTERS PATENT to Henry Dean, of Wood End, near Fareham, in the
County of Southampton, Surveyor, for the Invention of "IMPROVE-
MENTS IN PLOTTING' AND "COMPUTING SCALES FOR THE USE OF SUR-
VEYORS AND ENGINEERS.""
Sealed the 9th July 1866, and dated the 11th January 1866.
PROVISIONAL SPECIFICATION left by the said Henry Dean at the
Office of the Commissioners of Patents, with his Petition, on the
11th January 1866.
I, HENRY DEAN, of Wood End, near. Fareham, in the County of
Southampton, Surveyor, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PLOTTING," AND "COMPUTING.' SCALES FOR. THE USE
OP SURVEYORS AND ENGINEERS," to be as follows:
This Invention is, designed for the purpose of affording facilities for
plotting and computing with greater accuracy and despatch than can be
obtained by the usual method and by the scales as ordinarily constructed,
the Invention consisting principally in, forming a combined plotting and
computing scale, whereby, the same divisions being used for both plotting
and computing, error cannot possibly arise, owing to, the divisions, of the
plotting and computing scales not exactly corresponding. Besides ensuring

page_text: greater accuracy and despatch, this Invention also effects a considerable
economy, as a whole set of plotting, computing, and offset scales are
combined in one instrument.
In carrying out my Invention I first provide a piece of ivory, boxwood,
metal, or other suitable material of a convenient size to form the main
scale. The scales may be made of various sizes, but for ordinary use I
propose to make the main scale two feet long, one and a half inch wide,
and one-quarter of an inch deep, divided on each surface through a length
of twenty inches, and comprising upon one side scales of two, three, four,
and six chains to the inch plotting, and three and four chains computing,
and upon the other side an equal number of scales, including one and five
chains to the inch for Ordnance and Board of Health surveys, railway
sections, and the like. The main scale is only marked with the principal
or main divisions, such as furlongs, acres, chains, hundreds, and so forth,
the subdivisions for links, feet, rods, tens, and so on being made upon a
supplemental sliding scale hereafter described. By these means the main
scale can be numbered much more clearly, and the subdivision of one
division on the supplemental scales can be executed with much greater
accuracy than the whole scale could be subdivided, and at a much less
expense. The main or furlong and acre divisions on the main scale are
numbered in red, whilst chains, hundreds, fifties, and the like are numbered
in black. The main scale is provided with a longitudinal groove in each
edge running throughout its entire length, and in these grooves is accu-
rately fitted a sliding frame of metal, composed of two slides (one running
in each groove) connected together by two transverse bars passing at right
angles to the slides and parallel to each other across the face of the main
scale. This sliding frame carries two supplemental scales which are
feather-edged and are marked with the requisite subdivisions, links, feet,
tens, and so on, to correspond with the divisions on the main scales, the
central or "zero" point being marked upon them in red. These supple-
mental scales are capable of being adjusted and fixed in the parallel bars
so as to correspond exactly with the various scales on the main scale. The
sliding frame is provided with springs running in the grooves to give it an
easy and steady motion, and a stop is provided at each end to arrest the
sliding frame at the precise spot where the "zero" point on the supple-
mental scale coincides with the "zero" at either end of the main scale.
By removing either of these stops the sliding frame can be taken out and
reversed, thereby serving for both sides of the main scale. A projection
from the sliding frame carries the "station pricker," which is a needle held

page_text: up by a spring, but capable of being depressed so as to puncture the paper
when required. Another projection from the sliding frame carries the
"offset scale," which is mounted at right angles to the main scale. The
"offset scale" (which is of the same depth as the main scale) is marked
with similar divisions, two, four, and six chains to the inch on one side, and
on the reverse side other divisions corresponding with those of the main
scale, and has a longitudinal groove in which a slide works, the said slide
being graduated with the subdivisions like those on the supplemental scales
before described, and carrying the offset "pricker" at a point exactly
opposite to "zero," the pricker working through a groove cut entirely
through the centre of the "offset scale." The offset slide is also re-
versible so as to be used with either side of the scale. The "computing
frame" is mounted upon the sliding frame in precisely the same manner as
the "offset scale." To the slide of the "offset scale" is attached a hinged
flap, which may be folded down over either graduated edge so as to cover
up the subdivisions of the edge not in use, and thus prevent the possi-
bility of error by reading off the wrong scale. A similar contrivance
may also be placed upon the supplemental scales of the main sliding
frame..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Dean in the Great Seal Patent Office on the
11th July 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DEAN, of Wood End, near Fareham, in the County of Southampton,
Surveyor, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of January, in the year of our
Lord One thousand eight hundred and sixty-six, in the twenty-ninth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry Dean, Her special licence that I, the
said Henry Dean, my executors, administrators, and assigns, or such
others as I, the said Henry Dean, my executors, administrators, and
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,

page_text: and Isle of Man, an Invention for ""IMPROVEMENTS IN PLOTTING' AND
⚫ COMPUTING' SCALES FOR THE USE OF SURVEYORS AND ENGINEERS," upon the
condition (amongst others) that I, the said (Henry Dean, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, 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 Henry Dean, 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 and on reference to the accompanying Sheet
of Drawings, that is to say :-
This Invention is designed for the purpose of affording facilities for
plotting and computing with greater accuracy and despatch than can be
obtained by the usual method and by the scales as ordinarily constructed,
the Invention consisting principally in combining a set of plotting and
computing scales in one, whereby, the same divisions being used for both
plotting and computing, error cannot posssibly arise, owing to the divisions
of the plotting and computing scales not exactly corresponding. Besides
ensuring greater accuracy and despatch, this Invention also effects a con-
siderable economy, as a whole set of plotting, computing, and offset scales
are combined in one instrument.
In carrying out my Invention I first provide a piece of ivory, boxwood,
metal, or other suitable material of a convenient size, to form the main
scale. The scales may be made of various sizes, divided on one or both
surfaces. The one represented in the accompanying Drawing comprises
upon one side.scales of 2, 3, 4, and 6 chains to the inch plotting, and 3 and
4 chains computing, and upon the other side the Ordnance scale of 2500
plotting, computing, and scale of feet to correspond. The main scale is
only marked with the principal or main divisions, such as furlongs, acres,
chains, hundreds, and so forth, the subdivisions for links, feet, rods, tens,
and so on being made upon a supplemental sliding scale hereafter described.
By these means the main scale can be numbered much more clearly and
the subdivision of one division on the supplemental scales can be executed
with much greater accuracy than the whole scale could be subdivided, and
at a much less expence. The main or furlong and acre divisions on the
main scale are numbered in red, whilst chains, hundreds, fifties, and the

page_text: like are numbered-in black. The main scale is provided with a longitudinal
groove in each edge running throughout its entire length, and in these
grooves is accurately fitted a sliding frame of metal, composed of two slides
(one running in each groove) connected together by two transverse bars
passing at right angles to the slides and parallel to each other across the face
of the main scale. This sliding frame carries one, two, or more .supple-
mental scales which are feather-edged and are marked with the requisite
subdivisions, links, feet, tens, and so on, to correspond with the divisions
on the main scales, the central or "zero" point being marked upon them
in red. These supplemental scales are capable of being adjusted and fixed
in the parallel bars so as to correspond exactly with the various.scales on
the main scale. The sliding frame is provided with springs.running in the
grooves to give it an easy and steady motion, and a stop is provided at
each end to arrest the.sliding frame at the precise spot where the "zero"
point on the supplemental scale coincides with the "zero" at either end
of the main scale. By removing either of these stops the sliding frame
can be taken out and reversed, thereby serving for both sides of the main
scale. A projection from the sliding frame carries the "station pricker,"
which is a needle held up by a spring, but capable of being depressed so
as to puncture the paper when required. Another project on from the
sliding frame carries the "offset scale," which is mounted at right angles.
to the main scale. The "offset scale" (which may be of the same depth as
the main scale) is marked with similar divisions 2, 4, 3, and 6 chains to
the inch on one side, and on the reverse side other divisions corresponding
with those of the main scale, and has a longitudinal groove in which a
slide works, the said slide being graduated with the subdivisions like those
on the supplemental scales before described, and carrying the "offset
pricker" at a point exactly opposite to "zero," the pricker working through
a slot cut entirely through the centre of the "offset scale." The offset
slide is also reversible, so as to be used with either side of the scale. The
computing frame is mounted upon the sliding frame in precisely the same
manner as the "offset scale." To the slide of the "offset scale" is attached
a hinged flap, which may be folded down over either graduated edge so as
cover up the subdivisions of the edge not in use, and thus prevent the
possibility of error by reading off the wrong scale. A similar contrivance
may also be placed upon the supplemental scales of the main sliding
frame.
Such being the nature and object of my said Invention for " Improve-
ments in Plotting and Computing' Scales for the Use of Surveyors

page_text: and Engineers," I will now proceed to describe more in detail the manner in
which the same is to be or may be performed or carried into practical effect,
and in order that the same may be distinctly understood I have annexed
hereunto a Sheet of Drawings illustrative thereof, and have marked the
same with figures and letters of reference corresponding with those in the
following explanation thereof, that is to say :-
In the annexed Drawing, Figure 1 represents a plan view of one face of
a combined plotting and computing scale made according to my Inven
tion, and drawn the actual size for a two-foot scale; Figure 2 is a plan
view of the reverse face. A. A, is the main scale; B, B, the offset scale;
and C, C, the computing frame. Figure 3 is a transverse section taken
through the line A, B, in Figure 1; Figure 4 is a view of that end of the
offset scale which joins the sliding frame; Figure 5 is an enlarged section
across the offset scale at the line C, D, in Figure 1, shewing the details of
the offset pricker; Figure 6 is an enlarged edge view of part of the main
scale, showing one of the sliding frames with its supplemental scale; and
Figure 7 is an enlarged section of the station pricker. The main scale
A, A, is provided with a longitudinal groove a, a, in each edge running
throughout its entire length, and in these grooves is accurately fitted the
sliding frame D, D, composed of two slides b, b, (one running in each
groove) connected together by two transverse bars c, c, passing at right
angles to the slides and parallel to each other across the face of the main
scale, as seen at Figures 1, 2, 3, and 6. This sliding frame D, D, carries
one, two, or more supplemental scales E, E, (two being shewn at Figure 1
and one at Figure 2,) which are feather-edged and are marked with the
requisite subdivisions (links, feet, tens, and so on) to correspond with the
divisions on the main scales. These supplemental scales are for the
purpose of avoiding the necessity for marking the minor subdivisions on
the main scale, the central or "zero point being marked upon them in
red, and they are attached to the sliding frame D, D, by means of screws
d, d, fitting into holes in the bars c, c, of the frame, by loosening which
screws they can be adjusted and fixed on the parallel bars so as to corre-
spond exactly with any one of the various scales on the main scale.
Figure 8 shows another way of marking the supplemental scale E, E,
Figure 2, the zero point being X for plotting from the right hand and Y
from the left hand. The sliding frame D, D, is furnished with springs
running in the groove a, a, to give it an easy and steady motion, and a stop
e (Figure 6) is provided at each end of the groove to arrest the sliding
frame at the precise spot where the "zero" point on the supplemental
35

page_text: scale coincides with the "zero" at either end of the main scale; these
stops are fixed by small screws, on removing which the sliding frame can
be taken off and reversed so as to serve for both sides of the main scale.
A projection ff. from the sliding frame carries the station pricker (see
Figure 7), which consists of a needle g, g, held up by a spring h, h, and
furnished with a head by means of which it can be depressed so as to
puncture the paper when required. It will be seen that the needle repre-
sented in the accompanying Drawing is bent or cranked, the object of
which is enable it to perforate the paper exactly in the angle marked * in
Figure 1, but it can be made straight in some cases if required, and admits
of the same adjustment of depth of puncture as described with regard to
the offset pricker. A second projection i, i, from one of the slides b, b,
of the frame carries the offset scale B, B, which is mounted at right angles
to the main scale, having one end provided with a groove k, k, see Figure 4,
into which the projection i, i, fits, and is secured by two screws 1, l. I
may here observe that the computing frame C, C, is to be mounted upon
the sliding frame in precisely the same manner as the offset scale. The
offset scale B, B, is provided with a longitudinal dovetailed groove m, m,
in which a slide n, n, works. This slide is graduated with subdivisions
like the supplemental scales, and carries the offset pricker F at a point
exactly opposite to "zero;" the pricker working through a slot o, o, cut
entirely through the centre of the offset scale. The details of this part
are shewn clearly at the enlarged view, Figure 5. The needle p, p,
provided with a spring 7, 9, for raising it, and a head r, r, for depressing.
The needle carrier s, s, has a shoulder t, t, against which the head of the
needle comes so as to prevent it from perforating the paper too deeply,
and the head screwing on to the needle p, p, and resting upon the spring
is firm at whatever distance it may be screwed on, and by screwing it up
or down the depth to which the needle point punctures may be regu-
lated with the greatest accuracy, and by screwing the head r down to the
shoulder t, t, the needle is fixed. The offset scale shown in the Drawing
is of the same depth as the main scale, and is reversible, so as to be used
with either side of the scale, but in some instances, when it is required to
be feather-edged, it may be made thinner and not reversible. To the slide
of the offset scale is attached a hinged flap u, u, which may be folded
down over either graduated edge so as to cover up the subdivisions of the
edge not in use at the time, and thus prevent the possibility of error by
reading off the wrong scale. A similar contrivance may also be applied to
the supplemental scales E, E, of the main sliding frame, as shewn at Figure 9,
is

page_text: where each set of subdivisions is furnished with its respective covering
flap.
Having now described the nature and' object of my said Invention for
"Improvements in 'Plotting and Computing Scales for the Use of
Surveyors and Engineers," together with the manner in which the same is
to be or may be performed or carried into practical effect, I would remark
in conclusion that I claim as my Invention the construction, combination,
and arrangement of plotting and computing scales substantially as shewn
in the annexed Drawings and above described.
In witness whereof, I, the said Henry Dean, have hereunto set my
hand and seal, this Seventh day of July, in the year of our Lord'
One thousand eight.hundred, and sixty-six.
HENRY DEAN. (L.S.).