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"Copernicus, or Nicholas Koppernigk, was the founder of modern astronomy. From a school in Thorn Copernicus went to Cracow, where he studied medicine, theology, mathematics, and astronomy. He latterly came to the following conclusions: That the sun was the center of the system; that the earth was a planet like Mars and Venus; and that all the planets revolve round the sun."—(Charles Leonard-Stuart, 1911)

Globe of Copernicus

"Copernicus, or Nicholas Koppernigk, was the founder of modern astronomy. From a school in Thorn Copernicus…

"Saturn is the 6th of the major planets in order of distance from the sun, and the outermost known to the ancients. Its mean diameter is about 70,000 miles, its mean distance from the sun somewhat more than 872,000,000 miles, and its year or periodical revolution around the sun nearly twenty-nine and one-half years. Its mass is about 90 times that of the earth. Saturn is attended by ten satellites and surrounded by a system of flat rings, which are now supposed to be an immense multitude of small satellites mixed probably with vaporous matter."—(Charles Leonard-Stuart, 1911)

Saturn

"Saturn is the 6th of the major planets in order of distance from the sun, and the outermost known to…

The satellite of the earth, and classed as one of the secondary planets. It revolves around the earth in an almost circular orbit once each sidereal month, at a mean distance of 238,818 miles.

Moon

The satellite of the earth, and classed as one of the secondary planets. It revolves around the earth…

The celestial bodies that revolve around the sun and receive light and heat from it. This diagram shows the comparative sizes of the planets.

Planets

The celestial bodies that revolve around the sun and receive light and heat from it. This diagram shows…

One of the major planets, which is siexth in distance from the sun. It is the second planet in size, being exceeded only by Jupiter, and has a mean diameter of 71,000 miles.

Saturn

One of the major planets, which is siexth in distance from the sun. It is the second planet in size,…

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

Regiomontanus' Astrolabe

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

Later Astrolabe

A historical astronomical instrument used to predict positions of the Sun, Moon, planets and stars.

A diagram showing the planets of our solar system.

Planets

A diagram showing the planets of our solar system.

"Relative distance of the Planets. Having now given a short account of each planet composing the solar system, the relative situation of their several orbits, with the exception of those of the Asteroids, are shown in this figure. The orbits are marked by the signs of each planet, of which the first, or that nearest the Sun, is Mercury, the next Venus, the third the Earth, the fourth Mars then come those of the Asteroids, then Jupiter, then Saturn and lastly Herschel." —Comstock, 1850

Planet Distance

"Relative distance of the Planets. Having now given a short account of each planet composing the solar…

"The comparative dimensions of the planets." —Comstock, 1850

Planet Sizes

"The comparative dimensions of the planets." —Comstock, 1850

"Circular Motion of the Planets." —Comstock, 1850

Planet Motion

"Circular Motion of the Planets." —Comstock, 1850

The Earth in Space.

Earth

The Earth in Space.

Cause of the Curved Shape of the Earth's Orbit.

Earth Orbit

Cause of the Curved Shape of the Earth's Orbit.

The shape of the earth is that of a round ball or sphere slightly flattened at two opposite sides. Such a body is termed a <em>spheroid</em>. There are two kinds of spheroids-<em>oblate</em> and <em>prolate</em>; the former as the shape of an orange, the latter that of a lemon. The straight line that runs through the centre of a sphere or spheroid and terminates at the circumference is called the <em>diameter</em>. If the sphere rotates-that is, moves around like a top-the diameter on which it turns is called the <em>axis</em>. In the oblate spheroid the axis is the shorter diameter; in the prolate spheroid the axis is the longer diameter.

Oblate and Prolate Spheroid

The shape of the earth is that of a round ball or sphere slightly flattened at two opposite sides. Such…

If the earth were uniformly covered with a layer of water, the passage of the moon over any place as at <em>a</em>, would cause the water to lose its globular form, become bulged at <em>a</em>, and <em>b</em>, and flattened at <em>c</em>, and <em>d</em>. In other words, the water would become <em>deeper</em> at <em>a</em>, and <em>b</em>, at the parts of the earth nearest and farthest from the moon and <em>shallower</em> in all places 90 degrees or at right angles to these points.

Lunar Tide

If the earth were uniformly covered with a layer of water, the passage of the moon over any place as…

During new and full moon, the earth, moon, and sun are all in the same straight line, but, that during the first and last quarters, they are at right angles. The portions of the earth and moon turned toward the sun are illumined, the shaded portions are in the darkness. To an observer on the earth, the moon, at <em>a</em>, appears new, since the dark part is turned toward the person; at <em>b</em>, however, it must appear full, since the illumined portions are toward the person. At <em>c</em>, and <em>d</em>, the positions of the quarters, only one-half of the illumined half, or one quarter, is seen.

Cause of the Phases of the Moon

During new and full moon, the earth, moon, and sun are all in the same straight line, but, that during…

The flood tides are the highest, and the ebb tides are the lowest. These are called <em>spring tides</em>. They occur twice during every revolution of the moon-once at <em>full</em>, and once at <em>new</em> moon. When the sun and moon are 90 degrees apart, each produces a tide on the portion of the earth directly under it, diminishing somewhat produced by the other body. High tide, then, occurs under the moon, while the high tide caused by the sun, becomes by comparison, a low tide. Such tides are called <em>neap tides</em>.

Positions

The flood tides are the highest, and the ebb tides are the lowest. These are called spring tides.…

A diagram showing the order of the universe as expounded by Ptolemy. Its basic concept surmises that the Earth is the center of our universe. This diagram was widely accepted as fact for fourteen centuries until it was discredited.

Spheres of the Ptolemaic System

A diagram showing the order of the universe as expounded by Ptolemy. Its basic concept surmises that…

"The constellation which is prominent in early summer in the skies of the southern United States (where the whole of the magnificent tail clears the horizon), contains the first magnitude red star Antares and several of the second magnitude. With the Chaldeans and Greeks is extended over one sixth of the planetary circle, the scorpion being represented with exaggerated claw embracing a circular space where Libra is now placed." &mdash;Whitney, 1889

The Scorpio Constellation, with Libra

"The constellation which is prominent in early summer in the skies of the southern United States (where…