Illustrations
ILLUSTRATIONS
| Portrait of the Author | facing | |
| The Earth Showing North Polar Opening | facing | |
| A Photographic View of Ring Nebula and Spiral Nebula | facing | |
| Photograph of a Drawing Showing the Head of Donciti's Comet as Seen in 1853 | facing | |
| Enlarged View of Mars | facing | |
| Photographic Views of Mars, Showing Circular White Spot Extended Above the Planet's Surface | facing | |
| Discovery of the Mammoth Incased in Ice | facing | |
| The Central Sun as it Would Appear to an Explorer | facing | |
| Diagram Showing the Earth as a Hollow Sphere | facing | |
| The Earth Bisected Showing Central Sun | facing | |
| A Sectional View of the Earth's Interior | facing | |
| The Earth Bisected Showing Concentric Spheres According to Symmes' Theory | facing |