IMPROVEMENTS IN SCALES USED IN DRAWING AND LAYING DOWN PLANS
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
COLLARD DRAKE, of Elm Tree Road, Saint John's Wood, in the County of
Middlesex, Land Surveyor, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eighteenth day of February, in the fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said John Collard Drake, Her especial licence, full power, solo privilege and
authority, that I, the said John Collard Drake, my exors, admors, and
assigns, or such others as I, the said John Collard Drake, my exors, adiñors,
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 law-
fully might make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, and also in all Her said Majesty's Colonies
and Plantations abroad, my Invention of "IMPROVEMENTS IN SCALES USED IN
DRAWING AND LAYING DOWN PLANS;" in which said Letters Patent is con-
tained a proviso that I, the said John Collard Drake, shall cause a particular
description of the nature of my said Invention, and in what manner the
same is to be performed, to be inrolled in Her said 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Collard Drake, do hereby declare that the nature of my Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon
(that is to say):
The practice heretofore resorted to in drawing and laying down plans is to
use scales of metal, or wood, or ivory, which are little affected by change of
atmosphere when compared with the paper on which the plans are laid down,
such paper being united to linen or calico by means of paste, which not only
occasions great extension of the paper from saturation, rendering the paper
so united totally unfit for use until the paste shall become dry, but is also
greatly subject to alteration from atmospheric changes.
The consequences
are obvious; the scales of wood, or metal, or ivory, can never agree with the
varying material on which maps or drawings are made, by which very serious
errors and perplexing difficulties are the result. Now, according to my Inven-
tion, the scales used are to be made from the paper on which the nap
or drawing is to be laid down, and the scale so made and used for the
purpose of laying down the plan is, after the plan is made, at all times to go
with the map or plan, by which means the scale and the plan being of the
same materials, and similarly acted on by atmospheric changes, the scale will
at all times have the same relation to the plan as when the drawing or plan
was first produced from the paper scale; and by measuring any portion of the
plan or map by means of the scale (which has been used in laying down the
plan), the quantities indicated will at all times be correct if the plan has been
properly executed in the first instance, notwithstanding any expansion or
contraction which may have taken place in the plan and in the scale. And
although it is a great improvement on the old mode to make the scale from
the paper mounted on linen or cotton by paste, yet, in order to obtain the
fullest advantage of my Invention, I employ india-rubber cement in place of
paste in mounting the paper on linen or cotton. And in order to accomplish
this object, I, as. heretofore, evenly stretch the linen or cotton, and then damp
one surface of the paper, and on the other surface thereof I apply the india-
rubber cement (dissolved india rubber) in a thin coat, and as evenly as
possible, and I also lay a coat of the india-rubber cement on to the linen or
cotton, and then spread the paper on to the linen or cotton. By this means
it will be found that the paper so mounted will be in a far superior condition
for the purposes to which it is to be applied (vizt.). for laying down maps or
plans by means of scales made from the same, than paper mounted by means

page_text: of paste.
From the paper so prepared and afterwards joined in such sizes as
may be required, I cut a strip of the length and width I desire to have the
scale, and I divide it either by hand or otherwise, with a series of lines
according to the work to be done, and similar to divisions on scales now in
use, but I make no claim for dividing such paper scales. But as the paper
scale thus produced would not in itself be suitable for use, it is necessary to
have a straightedge or holder when using the scale in order to hold the scale
when required for the purpose of laying down plans, &c.
Figure 1 shews a portion of the paper scale, and Figure 2 shows a portion
of a straightedge or holder, having a portion of a scale applied thereto, so
that when the paper scale and the straight edge or holder are combined, they
form the working scale. Figure 3 shews an end view of the straightedge or
holder, with the scale therein, and Figure 4 shews an end view of the
straightedge without the scale, the under surface of the straightedge or
holder having a surface of paper on linen or cotton affixed thereon, leaving a
space to receive the scale, as is clearly shewn. Hence it will be seen, that
the paper scale will protrude beyond the straightedge, and the scale by which
the work is laid down on the plan at right angles to the straightedge or
holder will not depend on the accuracy of the edge of the paper scale, but on
the accuracy of the straightedge or holder and the offset scale, by which
portions of the plan are laid down at right angles to the straightedge. The
straightedge (holding the scale) will rest on the surface of the paper scale
when being used; and in order to facilitate the operation of placing the
scale, commonly called an offset scale, accurately on the divisions of the paper
scale, I prefer to use the scale Figure 5, the nature of which is clearly shewn
in the Drawing, there being a line of wire or horsehair, or other fibre, at a, a,
by which the divisions of the paper scale may be more correctly worked from
the lines a, a, being, in fact, coincident with and forming a continuation of the
outer edges of the scale commonly called an offset scale, and used for laying
down such parts of plans, &c. as are at right angles to the longer scale, and
this will be readily understood on examining Figure 5. In using scales
according to my Invention, the plan or drawing is to be laid down by working
from the paper scale, suitably held in a holder or straightedgo as described, in
conjunction with the offset scale before described; and when the plan is finished,
the paper scale used is to accompany the plan, and should at all times go
with it; and whenever it is desired to measure off the quantities of any parts
of the plan, the paper scale being laid thereon will accurately indicate the
quantities, notwithstanding any expansion or contraction in the plan, a similar
degree of contraction and expansion taking place in the paper seale also. It

page_text: will therefore be understood that, according to my Invention, that the paper for
the scale having been cut from the paper on which the plan is to be laid down,
the paper scale is then used for making or laying down the plan, and
then accompanies the plan so made, and thus is it at all times subject to the
same effects from atmospheric changes as the plan itself, I would remark,
that I am aware that scales have been before made on the paper on which a
drawing or plan is made or laid down, but such scale is only used by the aid
of compasses, either in laying down the plan, or afterwards for measuring off
parts thereof, as is well understood, but such scales are wholly unsuited
when the scale itself is required as an instrument to lay down plans, to
which object my Invention is confined. And I am aware that separate paper
scales of pasteboard have been before used for drawing purposes; I do not,
therefore, claim the same, and such pasteboard scales would not be suitable
for carrying out the object of my Invention.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that what I claim as my
Invention are the modes herein described of constructing paper scales, with
apparatus for applying the same in drawing and laying down plans, whereby
the scales and the plans produced by the aid thereof will be liable to the same
effects of expansion and contraction.
In witness whereof, I, the said John Collard Drake, have hereunto set
my hand and seal, this Eighteenth day of August, One thousand cight
hundred and forty-one.