Античный мир глобусов и небесные шары

Antique World Globes and Celestial Globes

Antique globes of Earth delineate the political boundaries of nations and the understanding of cartography at a given point in world history. Celestial globes display the geographical features of the moon and planets, as well as the arrangement of constellations in the sky. This product category includes antique terrestrial and celestial globes, maps, and other classic cartographic collectibles, along with related accessories such as stands and frames.

World and celestial globes first appeared in ancient Greece and Rome. Modern collectors can find many examples dating from the 19th and 20th centuries.

The nominal scale is the ratio of the size of the representations of geographical features on the map to the actual size of the features in reality.

For example, Earth has a diameter of approximately 8,000 miles, which is equal to approximately 40 million inches. A globe with a diameter of 40 inches would be one-millionth the size of Earth, and would have a scale of 1:1,000,000.

Globes usually have their nominal scale printed on them. As an aid for measurement, they often have a bar scale printed on them. The bar scale is like a ruler that indicates scaled distances. The bar scale will usually be marked in units of thousands of miles. To measure the distance between two points, stretch a string or thread between them, then hold the marked-off distance against the bar scale.

Classic mappings of the world will have a bar scale in miles. However, the nominal scale is the same for the metric system. Newer maps may have a bar scale marked off in kilometers.

Since the moon and planets have different diameters, their globes have different nominal scales compared to one of Earth that is the same size.

Although some stars are many times farther away than others, constellation mappings can accurately portray their apparent positions in the sky, as well as the location of the celestial equator and north and south poles.

An orrery is a mechanical device mounted on a stand that shows the angular positions of interplanetary objects as they orbit one another. As the user turns a crank, the orrerys gears and arms cause the celestial objects to revolve around the stand and each other, displaying their relative positions.

Orreries that portray only the positions of Earth, the moon, and the sun are called tellurians or tellurian orreries.

As the distances between the sun and the planets are thousands of times greater than the sizes of the worlds, it is not practical to make orreries show all distances to the same scale. Despite this limitation, orreries are used as teaching aids to demonstrate such astronomical concepts as the phases of the moon.

Features of items in this category may include:

• Interior lighting
• Stands
• Automatic rotation
• Magnetic levitation
• Handbooks
• Frames