Analemma

An analemma is a curve representing the angular offset of the sun from its mean position on the celestial sphere, as viewed from Earth. It typically forms a figure-eight shape (sometimes elliptical) and is commonly found in the Pacific Ocean. By accounting for the Earth's axial tilt, the analemma can precisely calculate mean time (the time we set our clocks to) and mark solstices and equinoxes.

Armillary Sphere

An armillary sphere is an instrument with concentric rings used to show the orbits of planets, the zodiacal band, and the circles of terrestrial and celestial measurement, such as the Tropics of Cancer and Capricorn, and the equator. Sometimes, an armillary sphere is equipped with a solar system model or is mounted as a garden sundial.

Axis

The Earth's axis is the rod or shaft positioned at the Earth's center. The ends of this axis are the North Pole (top) and the South Pole (bottom). The Earth's rotation occurs around this axis.

Polar Cap

Polar caps are most common on European globes. The poles are no longer covered with paper but with circular pieces of paper (polar caps), rather than traditional triangular paper sections.

Cartouche

A cartouche is a decorative emblem on a globe or map that identifies the manufacturer and its location, sometimes including the globe's model and date of manufacture. The design of the cartouche varies according to the cartographer and the period's style.

Cradle Mounting

Cradle mounting is a type of mounting that allows the globe to be removed from its base for close inspection. The globe is fixed within a cradle, allowing it to spin freely in any direction without an axis.

Degree

The unit of measurement used in globes, representing 1/360 of the circumference.

Diameter

A line passing through the center of a sphere, measuring the diameter. If the radius of the sphere is known, multiplying it by 2 will give the diameter. The radius is the distance from the center to the edge of the sphere.

Hemisphere

Any half of the Earth's surface (i.e., Northern Hemisphere, Southern Hemisphere, Western Hemisphere, Eastern Hemisphere).

Equator

A major circle around the Earth, midway between the poles, dividing the Earth into the Northern and Southern Hemispheres.

Equatorial Band

A band covering the equator, often covering the seams of machine-pressed globes.

Equinox

Twice a year, usually around March 21 and September 23, the sun's rays are perpendicular to the equator, resulting in equal day and night lengths worldwide.

Earth

The only true world map, produced in the form of a spherical globe.

Greenwich Meridian

Also known as the Prime Meridian, it is the reference point for measuring east and west longitudes. The Prime Meridian (0 degrees longitude) passes through Greenwich and serves as the basis for standard time calculation.

Grid

The network of latitude and longitude lines on the Earth's surface.

Horizon Ring

A ring on a globe representing the horizon, dividing the globe into hemispheres. It is usually calibrated in degrees, miles, hours, compass directions, days of the month, and zodiac signs.

Axial Tilt

The Earth's axis is tilted 23.5 degrees relative to its orbital plane.

International Color Scheme

A method of coloring contour layers on maps and globes to display elevation, where green represents lower elevations, yellow represents medium elevations, and orange and brown represent higher elevations.

International Date Line

An imaginary line marking the start and end of a day. With some local deviations, it generally follows the 180-degree meridian.

 

Latitude and Longitude

Latitude and longitude help locate points on the Earth and are used as a navigational system. They are the horizontal and vertical lines that cover the globe, collectively known as the grid.

Meridian

A metal band encircling the globe halfway or entirely, usually attached to the poles and the base.

Mounting

The structure to which the globe is attached, holding it in place. See definitions for various types of mounts (simple mounts, cradle mounts, fixed mounts).

Parallel of Latitude

East-west lines on the globe parallel to the equator.

Simple Mounting

A globe mounted on a base without any form of meridian.

Rotation

The spinning of the Earth around its axis.

Scale

The numerical relationship between actual distances on the Earth and the distances represented on the map.

Solstice

Around June 21 and December 22 each year, the sun's rays reach the boundary of the Tropics of Cancer and Capricorn.

Southern Hemisphere

The half of the Earth's surface south of the equator.

Sphere

Another term for a globe or a ball. See also "Orb."

Fixed Mounting

A type of mounting where the sphere and the full meridian cannot be removed from the base.

Globe

A mounted sphere displaying the world.

Time Dial

A fine metal ring, divided into 24 parts, often found on the top of 20th-century American globes, engraved or stamped with hours of day and night. It can be used to calculate the time difference between various locations on Earth.

Western Hemisphere

Generally refers to half of the Earth, including North and South America.

Zodiac

An imaginary band in the sky extending 8-9 degrees on either side of the ecliptic, divided into 12 parts, each represented by a symbol.