GLOBE. 
dity of a Globe,” multiply the cube of the 
diameter by .5236 (viz. one-sixth of 3.1416) ; 
or multiply the surface by one-sixth of the 
diameter. 3. “ For the Surface of a Seg- 
ment,” multiply the diameter of the globe 
by the altitude of the segment and the pro- 
duct again by 3.1416. 4. “ For the Soli- 
dity of a Segment,” multiply the square of 
the diameter of the globe by the difference 
between three times that diameter and 
twice the altitude of the segment, and the 
product again by .5236, or one-sixth of 
3.1416. 
Hence, if d denote the diameter of the 
globe, 
c the circumference, 
a the altitude of any segment, and 
p 2 = 3.1416 ; then 
The surface. The solidity. 
In the globe pd* — cd | pd 2 
In the segment pad a pd 2 x 3d — 2a. 
See Mensuration. 
Globe, in practical mathematics, an ar- 
tificial spherical body, on the convex sur- 
face of which are represented the countries, 
seas, &c. of our earth ; or the face of the 
heavens, the circles of the sphere, &c. That 
with the parts of the earth delineated upon 
its surface, is called the terrestrial globe ; 
and that with the constellations, &c. the ce- 
lestial globe. These globes are placed in 
frames, with other appurtenances. Their 
principal use, besides serving as maps to 
distinguish the outward parts of the earth, 
and the situation of the fixed stars, is 
to illustrate and explain the phenomena 
arising from the diurnal motion of the 
earth. 
The globes commonly used are composed 
of plaster and paper in the following man- 
ner : A wooden axis is provided, somewhat 
less than the intended diameter of the 
globe, and into the extremes two iron wires 
are driven for poles : this axis is to be the 
beam or basis of the whole structure. On 
the axis are applied two spherical or rather 
hemispherical caps, formed on a kind of 
wooden mould or block. These caps con- 
sist of pasteboard or paper, laid one lay 
after another on the mould, to the thickness 
of a crown-piece : after which, having 
stood to dry and embody, making an inci- 
sion along the middle, the two caps thus 
parted are slipped off the mould. They 
remain now to be applied on the, poles of 
the axis, as before they were on those of the 
mould ; and to fix them in their new place, 
the two edges are sewed together with 
packthread, &c. The rudiments of the 
globe thus laid, they proceed to strengthen 
and make it smooth and regular. In order 
to this, the two poles are hasped in a metal- 
line semicircle of the size intended ; and a 
kind of plaster made of whiting, water, and 
glue, heated, melted, and incorporated to- 
gether, is daubed all over the paper sur- 
face. In proportion as the plaster is ap- 
plied, the ball is turned round in the semi- 
circle, the edge of which pares off what- 
ever is superfluous, and beyond the due di- 
mension, leaving the rest adhering in 
places that are short of it. After such ap- 
plication of plaster, the ball stands to dry ; 
which done it is put again in the semi- 
circle, and fresh matter applied : thus they 
continue alternately to apply the composi- 
tion, and dry it, till the ball every where 
accurately touches the semicircle ; in which 
state it is perfectly smooth, regular, a fid 
complete. The ball thus finished, it re- 
mains to paste the map or description on it. 
In order to this, the map is projected in se- 
veral gores or gussets, all which join accu- 
rately on the spherical surface, and cover 
the whole ball. To direct the application 
of these gores, lines are drawn by a semi- 
circle on the surface of the ball, dividing it 
into a number of equal parts corresponding 
to those of the gores, and subdividing those 
again answerably to the lines and divisions 
of the gores. 
The papers thus pasted on, there remains 
nothing but to colour and illuminate the 
globe, and to varnish it, the better to resist 
dust, moisture, &c. The globe itself thus 
finished, they hang it in a brass meridian, 
with an hour-circle and a quadrant of alti- 
tude, and thus fit it into a wooden hori- 
zon. 
There are ten principal circles repre- 
sented upon globes, viz. six greater and four 
lesser ones. The greater circles are the ho- 
rizon, meridian, and equinoctial, as it is 
called on the celestial, and equator on the 
terrestrial globe, the ecliptic drawn along 
the middle of the zodiac , and the two co- 
lures. 
The lesser circles, of principal use, are 
the two tropics and two polar circles. 
Of these circles some are fixed, and al- 
ways obtain the same position ; others 
moveable, according to the position of the 
observer. The fixed circles are the equator 
and ecliptic, with their parallels and secon- 
daries ; which are usually delineated upon 
the surface of the globes. The moveable 
Z 2 
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