Improvements in and relating to the Manufacture of Maps and the like.
Year: 1899

page_text: Date of Application, 18th Aug., 1899
PROVISIONAL SPECIFICATION.
Improvements in and relating to the Manufacture of Maps
and the like.
I, BARON NICOLAS TORNAU, of 5, Priaschka, St. Petersburg, Russia, do hereby
declare the nature of this invention to be as follows:-
-
Maps on which, as on school wall-attached maps, every thing the subject of
observation, whether referring to configurations of the land or of the water or the
like, needs to be indicated with chalk in the course of the lesson, in order that it
may be brought prominently under the notice of the pupils and impressed on their
memory, have hitherto been made of linen prepared with oil.
The important point in the production of these maps is that the surface of the
latter should be sufficiently rough to take the chalk well, and that the chalk marks
should show up clearly. The latter must, however, be capable of being easily
rubbed out or washed off. Hitherto, the attempt to effect this has been made by
producing a slate-like surface and printing the map thereon. This on a slate-like
or merely a rough surface is very difficult. The colour has to be put on very
thickly and the lines of latitude and longitude and the net-work of rivers printed
in a different colour. Thereby all the lines of the second printing or impression
project from the surface so far that, when chalk is used on the map, it meets with
resistance in these places and adheres very thickly but does not come into contact
at all with the surface of the map in the places lying immediately behind or
adjacent to such higher portions. Thus very irregular lines are produced and the
map is easily injured by the continuous striking of the chalk against projections
from the surface.
In order to obviate all these disadvantages the inventor proposes that the
ordinary maps produced by printing, should be converted into maps for purposes
of demonstration by covering their surfaces uniformly with varnish, which before
drying should be dusted over with powdered pumice stone, glass, silicate or similar
material. Maps of this kind have all the fineness that would be secured by simply
printing on a flat surface. Neither the lines of longitude and latitude, nor the
net-work of rivers etc. require to be put in subsequently by means of oil-colour or
slate-colour. The surface of the map consequently remains entirely uniform and
the chalk marks which are made on this surface appear as clear unbroken lines.
Since the chalk does not strike against any projection from the surface, the map is
not damaged and wears away quite evenly. Even when repeated washing off of
the chalk with sponges and brushes, has deprived the uniformly rough surface
of so much of its roughness or biting character that the chalk no longer adheres
sufficiently, it is easy to roughen the surface again as may be desired by once more
covering it with a coat of varnish and fresh powdered pumice stone, or one of the
other suitable materials.
Whilst linen or cloth maps prepared with oil are smooth and lustrous, and
shine (owing to the glazed surfaces) so that they cannot be viewed from every
point, the maps made according to the present invention are quite lustreless, or

page_text: dull and may be viewed from any part of the room, no matter on which side they
are illuminated.
If this process be employed for producing wall maps which are usually rolled
up, the use of linen with a coating of india-rubber or similar material is desirable.
With this a specially smooth surface for printing on can be produced. On this
surface, the map is printed in the usual way and then dealt with according to
the present process. Thus, in fact, by this process, maps are made which surpass in
durability those made of linen or cloth by ordinary processes, and withstand even
the action of damp or moist air; such strengthened and improved maps can be very
cheaply made suitable for being drawn on with chalk for purposes of instruction."
Dated this Eighteenth day of August 1899
Improvements in and relating to the Manufacture of Maps
and the like.
I, BARON NICOLAS TORNAU, of 5, Priaschka, St. Petersburg, Russia, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to a process of covering maps, charts and the like,
employed for lecturing and teaching purposes, with a transparent slate-like layer,
in order that markings may be made thereon with chalk or other similar erasible
material.
These maps or charts are of two kinds; 1st, the so-called oil-cloth maps (maps
of linen prepared with oil) and 2nd, the so-called slate paper and linen maps.
The production of these two kinds of ordinary maps is identical, in so far that
geographical features are printed on a ground specially intended for drawing on.
As a ground for the first kind of maps a more or less dull or matt-surfaced cere-
cloth is employed, whereas, the ground for the second kind is covered with a
specially prepared slate-like coating.
For printing in the lines of latitude and longitude or other geographical
features, fatty pigments or inks are employed, the oil cloth maps being printed
in oil-colours and the slate maps in either oil-colours or in specially prepared
colours, in the preparation of which the constituent parts of the slate-like coating
for the ground are used.
pro-
Although the second kind of map has been found far more suitable than the first,
nevertheless considerable disadvantages are inherent to both. The method of
ducing the two kinds of maps is exceedingly unsatisfactory. In the first place,
printing on a slate-like or rough surface is very difficult. Further, the colours,
or printing ink, must be laid on thickly, and the maps are thus wanting in
accuracy and sharpness and are defective. Also, the rivers in such maps appear
angular and are not symmetrical, the coast lines show gaps or spaces (that is,
the water does not appear to always come flush with the land) and so on.
super-printing of the topographical features which project conspicuously above
the ground is attended with considerable disadvantages; the drawing of unbroken
lines is well-nigh impossible, and the continuous action of the chalk or other
material injures the maps to a certain extent and finally renders them useless.
The

page_text: Moreover, oil-cloth maps, if kept rolled up for any length of time, may quickly
become sticky, and the slate maps are readily broken or cracked, or parts of the
surface peel off.
The object of the present invention is to obviate the disadvantages connected
with maps intended for drawing on by means of the following process, whereby
not only geographical maps, but anatomical, mechanical, technical, mathematical
and other similar scientific charts or illustrations may be prepared, so as to admit
of being drawn or written on.
In order that markings or delineations with chalk, pastel or the like, may be
made on a given surface, it is necessary that such surface should have a certain
degree of roughness or coarseness, about the same as that of slates or slate-boards.
According to my invention, this is obtained by applying to the surface of the
map a coating of a very viscid or tough and adhesive varnish by means of a
printing roller,--such a varnish, for instance, as the "extra strong mordant
varnish 14 N."-manufactured by Lorileux & Cie., 16 Rue Suger, Paris. Im-
mediately after a layer of this material has been applied, and before the same
hardens, a quantity of pulverised pumice stone, silicate, glass or the like, is
sprinkled over it. As the particles of the powder which I employ, unite with the
varnish, a transparent coating is formed on the surface so treated. This surface
has the necessary degree of roughness for being easily marked with chalk, pastel
or similar erasible material. It is, however, not possible to apply such a varnish
directly to every material, since certain materials such as paper, paste-board, etc.,
absorb a part of the varnish. These materials must, therefore, be furnished with
a suitable damp-proof coating. For this purpose the well-known Pegamoid
coating can be successfully employed. It is only after the absorbent power of some
materials has been reduced or thus altogether neutralized that the laying on of
the covering intended to be drawn on should be proceeded with. The varnish
sprinkled or dusted according to this process forms a coating which is transparent,
exceedingly adhesive, slightly rough, and uniform and quite dull, on any surface
intended to be drawn on, and to which it is applied.
Amongst others, the following advantages of my invention will be apparent;
(1). Since the sprinkled varnish forms a uniform transparent coating for the
surface covered therewith, any fine and sharp representations, whether in the
form of maps or otherwise may be covered with it, without the fineness and
sharpness being impaired. Thus a map covered with the sprinkled varnish may
be used not only for being drawn on, as in the case of oil-cloth maps and slate
maps, but also for the specific study of geographical elements. For such special
study of the forms and sizes of the elements or features, maps printed in two
distinctly different tones are more particularly suitable for marking. On these
maps the land is dark, the water light and the lines of latitude and longitude
where they cross these tones, are alternately dark on a light ground and light on
a dark ground. With maps printed in this way, the proportions of land to water
are very clearly shown, and the coast lines and river-beds are sharply defined.
Moreover, these maps have the advantage that if marks be made on them with
coloured chalk, all such marks will be plainly seen. As already mentioned, by
means of this process not only geographical maps but representations of other
kinds for lecturing and teaching purposes can be prepared. For example, the
representations of a human frame, a skeleton, for drawing thereon the muscles,
the frame-work of a machine for setting out therein the various parts of such
machine, and the like, could be employed for lecturing or teaching, if treated
according to this invention.
(2). The durability of the coating produced by the sprinkled varnish is so great,
that it will not only stand repeated washing with a moist sponge, but even with a
damp brush. It is obvious that the use of a damp brush must only be resorted to
when the coating has become very dirty by being repeatedly drawn or written
upon.

page_text: (3). The slight, uniform roughness of the coating allows fine, thoroughly
uniform and sharp lines to be drawn.
"
#.
(4). In case, the chalk etc. does not bite the surface owing to repeated marking
and washing off, it is easy to restore the roughness of the latter. It is only
necessary to apply a fresh coating of varnish thereto and to sprinkle it again with
pumice stone before it becomes dry, as previously described.
(5). The coating is so matt or dull that it does not reflect the light at all.
(6). The method of production is cheaper than those hitherto employed, since
the materials which are necessary for the coating mentioned, are not expensive
and surfaces which are already printed can be treated.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claini is
A process for preparing representations such as maps, charts and the like, for
lecturing and teaching purposes, the distinguishing feature of which is that the
representation produced in the ordinary manner by drawing or printing is covered
with a varnish coating and before drying, sprinkled with a powder made of
pumice stone, silicate, glass or the like, for the purpose of producing a transparent,
slate-like and uniformly rough surface on the map or other representation, so
that any writing or drawing may be made thereon with chalk, or other erasible
material, substantially as described.
Dated this Thirteenth day of November 1899.
For the Applicant,
GEDGE & FEENY,
Chartered Patent Agents, 60, Queen Victoria Street, London, E.C.