Stargazers and Sunwatchers
This section defines east, north, south, and west in terms of the motion of the Sun; seasons are shown as a a consequence of the fact that sunrises and sunsets migrate southward in the winter and northward in the summer.
The Celestial Sphere
This section describes the apparent rotation of the night sky, the role and position of the Pole Star, and the difference between the motion of the stars and elements of the solar system -- the Sun, the Moon, and the Planets.
Finding the Pole Star
This section describes the constellations of the Big Dipper and Cassiopeia, and their use in finding the Pole Star, with some brief historical interludes.
This section covers the apparent motion of the Sun, Moon and planets across the sphere of "fixed stars" (celestial sphere). The concept of the ecliptic (path of the sun along this sphere) is described from different perspectives.
Making a Sundial
This chapter teaches the design, principle, and orientation of a sundial. It also provides instructions for creating a paper sundial.
Seasons of the Year
This section shows that the axial tilt of the Earth varies the length of days and the angle at which the Sun's rays hit the same spot throughout the year, giving rise to seasons.
The Angle of the Sun's Rays
This section shows that the greatest elevation of the Sun above the horizon is at noon, when the Sun -- in the northern hemisphere -- is directly south of the observer.
The Moon: the Distant View
This chapter provides a brief overview of the moon, its apparent behavior, and its role in time keeping.
The Moon: a Closer Look
This chapter provides an overview of the moon's surface features and a brief history of humanity's discovery of these. It also provides a brief overview of their exploration in the space age.
Latitude and Longitude
Introduces the concepts of longitude and latitude
This section describes how astronomy was used by early navigators for guidance.
This section introduces polar coordinates and relates them to navigation and the concepts of longitude and latitude.
The Cross Staff
This section describes the cross-staff, an old device used to find one's position on earth.
This section covers different methods of keeping time as used by various civilizations and explains them through the framework of periodic astronomical events.
This section describes the causes and effects of the precession of Earth's axis: it reviews the history of humanity's discovery of this phenomenon and then introduces modern theories of long-term weather changes due to this phenomenon.
The Round Earth and Columbus
This section briefly describes the debate on the size of the Earth and how this affected Columbus' voyages.
Distance to the Horizon
This section covers the relationship between the heights of objects and the distance at which they can be seen from the surface of the earth.
This section overviews parallax, or the apparent change in position of an object in different lines of sight. It then shows applications how this phenomenon can be used to find distances between objects.
Estimating the Distance to the Moon
This section describes how simple observations allow one to estimate the distance to the moon, with a historical aside on the Greek astronomer Aristarchus. It also overviews the concept of eclipses.
Distance to the Moon, Part 2
This section describes how solar eclipses can be used to estimate the distance to the Moon, as was done by Hipparchus.
Does the Earth Revolve Around the Sun
This section shows how Aristarchus used the position of the half-full moon to estimate the distance to the Sun, and why this led him to believe that the Earth may be revolving around it.
The Earth's Shadow
This section elaborates a statement from previous chapters -- why the fact that the sun is a disk influences the size of Earth's shadow during a lunar eclipse.
This section introduces the various elements of the solar system. It also overviews the planets and their apparent motions -- retrograde and prograde.