IMPROVE- MENTS IN THE CONSTRUCTION AND MANUFACTURE OF CELESTIAL AND TERRESTRIAL PROVISIONAL SPECIFICATIONAL GLOBES FOR THE STUDY OF ASTRONOMY & GEOGRAPHY
Year: 1855

page_text: LETTERS PATENT to Alexander Clark, of Gate Street, Lincoln's Inn Fields,
in the County of Middlesex, Engineer, for the Invention of "IMPROVE-
MENTS IN THE CONSTRUCTION AND MANUFACTURE OF CELESTIAL AND TERRESTRIAL
PROVISIONAL SPECIFICATION left by the said Alexander Clark at
the Office of the Commissioners of Patents, with his Petition, on the
10th March 1855.
I, ALEXANDER CLARK, of Gate Street, Lincoln's Inn Fields, in the County of
Middlesex, Engineer, do hereby declare the nature of the said Invention for
IMPROVEMENTS IN THE CONSTRUCTION & MANUFACTURE OF CELESTIAL & TERRES-
TRIAL GLOBES FOR THE STUDY OF ASTRONOMY & GEOGRAPHY" to be as follows:
My improvements in the manufacture of globes relate principally to the
foundation on which the paper gores or segments representing the carth's
surface & the positions of the celestial bodies are placed, & consists in using
a hollow glass globe for the purpose. The map or paper representation is
printed in the ordinary way, & cut into the necessary segments::or:gorės. I
apply these to the inner surface of the hollow globe, & cause them to adhere
by a cement that will not detract from the clearness of the tengraving; thus
the engraved representation will always be protected by the covering of glass,
& at the same time will be clearly visible, & present an enduring surface..
These glass globes may be blown in the ordinary way; & leaving a hole in
one part for the introduction of the engraving: They are to be subsequently
mounted on axes & in stands or frames in the usual manner

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Clark in the Great Seal Patent Office on the
10th September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
CLARK, of Gate Street, Lincoln's Inn Fields, in the County of Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of March, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Iler
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alexander Clark, Her special licence that I, the said Alexander Clark, my
executors, administrators, and assigns, or such others as I, the said Alexander
Clark, 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, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE CON-
STRUCTION AND MANUFACTURE OF CELESTIAL AND TERRESTRIAL GLOBES FOR THE
STUDY OF ASTRONOMY AND GEOGRAPHY," upon the condition (amongst others)
that I, the said Alexander Clark, by an instrument in writing under my
hand and scal, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the saine 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 Alexander Clark, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
My Invention of improvements in the construction and manufacture of
celestial and terrestrial globes relates to the foundation on which the paper
segments or gores representing the earth's surface or the position of the
celestial bodies are placed, which consists in the use of hollow glass globes for
the purpose; the map or printed representation being placed inside is protected
thereby.
My Invention further relates to the application of glass hemispheres to the
surface of globes, otherwise constructed somewhat in the ordinary manner, in
order to afford similar protection for the printed representation, and to render
the surface of the globe of an enduring character.

page_text: My Invention may be carried out in two different ways:-Glass may be
used for the foundation on which the printed map solely depends, or the map
may be first applied to a foundation, and the glass placed close over it in such
manner as to exclude dust and dirt, and otherwise to protect the printed
surface from the atmosphere. When the glass is used as the foundation for
the printed map, I produce it in the form of a globe in one piece, which is
blown in the ordinary way, as well understood by glass-blowers, and afterwards
annealed, as usual. In making these glass globes, that part which is to repre-
sent the south pole is at the point of the glassblower's rotating tube or stick,
where an opening about three inches in diameter is formed, when it is cut from
that instrument. This opening is sufficient to admit the easy introduction of
the hand, which opening will be situate at the south pole of the finished globe.
The maps are printed in the ordinary manner, and cut into gores at the lines
marking the degrees of longitude or meridians. The ordinary maps are usually
printed in twelve gores, dividing the circumference evenly, but I prefer that
they should be in twenty-four parts, as I find that the paper may be applied to
the glass more evenly in the narrow gores than in the wider gores applied
externally in the ordinary manufacture. The printed maps, if coloured, should
either be tinted in colours that will not run in the after treatment they are to
receive, or they should receive a slight coating of varnish to fix them. Pre-
viously to applying the printed surface to the glass globes, a hole is drilled at
the north pole for the passage of the axis on which the globe is to be mounted,
and the large hole at the south pole is ground a little conical, the larger part
outwards, and a piece of glass fitted and ground therein to form and make up
the whole sphere. This piece has also a hole bored through the centre for the
passage of the axis to carry the south pole. The lower portion of the gores
(as much as cover this separate piece) must be cut off and applied thereto
separately.
The gores after having been prepared as before described are treated with a
solution of gum or other transparent adhesive material, which is applied to the
printed surface of the map, and of such consistence as will cause the map to
adhere to the glass. The gores are then separately placed inside the globe and
applied to the interior surface of the glass; the hand of the operator having
easy access to affix the gores in proper position and arrangement. In preparing
the glass globe to receive the gores, I paste or otherwise cement a narrow strip
of paper round the exterior of the globe at the line of the equator. I then
divide this correctly into a number of equal divisions corresponding with the
number of gores to be applied. The opening near the south pole may also be
similarly divided to facilitate the adjustment of the gores at that point: At

page_text: the north pole the points of the gores are of course carried to the centre. The
gores thus treated with a solution of gum are now carefully applied to the
inside of the globe to which they adhere, placing them correctly according to
the divisions layed off at the line of the 'cquator. In applying the first gore a
thin strip of metal having a straight edge bent and fixed round the outside of
the-globe, with the straight edge intersecting the poles will facilitate the adjust-
inent of the first gore correctly, or such a guide may be applied from time to
time as the work progresses. In globes made in this way the atmosphere will
be entirely excluded from the surface of the map, and will almost entirely pre-
vent discolouration.- Abrasion or injury of the map surface will also be prevented,
which at the same time will be distinctly and clearly visible through the glass.
The globe thus formed will-present an enduring surface which cannot be affected
by-use, which in globes made-heretofore soon renders them unsightly; and the
engraving indistinct. This globe-is mounted on its axis in the brazeni meridian,
and in a stand in the usual manner. I form the axis of one rod passing quite
through the globe, the hour circle being fixed to it at the north pole, while, the
corresponding circle at the south pole is loose, and has its centre pressed up by
a nut and screw on the axis, thus holding the globe, and at the same time
pressing-up-the conical plug piece, closing the opening at the south pole. As
well known in the application of gores. in the ordinary manufacture of globes,
the gores are cut at the meridian lines, the line being left. at the edge
of one gore, which is brought close to the adjoining gore, but when placed
inside the glass.globe it may overlap the adjoining gore a little, or merely comeė
sufficiently-close to cover the whole surface. In constructing the larger kinds
of globes, the gores may be further divided at the equator to render them more
easy of application. Celestial globes may be manufactured in a similar manner,
taking care.to make the opening round the axis where there are fewest repre-
sentations of the heavenly bodies, in order to interfere as little as possible with
the distinctness of the map. These globes may also be covered with glass, in
the manner next-herein-after described.
gores
of the
:
Instead of causing the
map to depend entirely on the glass globe
as their foundation and support,. I sometimes cement them to an internal
foundation, which may be of the ordinary construction. I then apply two glass
hemispheres to the surface of the globe, uniting them at the equator, they
having been previously fitted and ground together at the equatorial line. These
hemispheres have also holes bored at the poles for the passage of the axis,
which as before goes quite through the globe, the nut and screw on the axis
compressing the. hemispheres together, and sustaining the whole in proper
position, and in close contact with printed surface of the globe: In order to

page_text: exclude the atmosphere and dirt from between the glass and the map, I apply
a little gum or other adhesive material all round the junction of the hemi-
spheres at the equator, and at the north and south poles around the holes
through which the axis passes. To ensure the perfect exclusion of dust and
atmosphere, the cement may be carried between the glass and the map for a
short distance at those points, taking care to use the necessary precautions to
prevent the colours of the map running, if coloured.
These hemispheres of glass may be blown and flashed, as well understood,
and at the same time trimmed as nearly as possible to the proper depth of
hemisphere. In order to render them more truly spherical they may be set
and annealed on hemispherical moulds. They are subsequently ground on a
flat surface to form a correct line at the equator, and may be further ground
together on a globe, or an axis, or other contrivance to keep their edges in
coincidence. In the manufacture of small globes, as first herein described,
in which the hole at the south pole cannot be large enough to admit the
hand of the operator for the purpose of cementing the gores on the inside, a
small hole may be made, and an instrument used in applying the gores.
Having described the nature of my Invention, and the manner in which
it is to be performed, I would have it understood that what I claim is, the
application of glass as a surface to globes, as a protection for the map or printed
representation of the earth's surface, or the representation of the celestial bodies,
as herein-before described.
In witness whereof, I, the said Alexander Clark, have hereunto set my
hand and seal, this Tenth day of September, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
W. CLARK, Patent Agent,
53, Chancery Lane, London..
ALEXANDER CLARK. (L.S.)