LIST OF ILLUSTRATIONS.
| FIG. | PAGE | |
| 1. | Section of the Eye | 24 |
| 2. | A Camera Obscura | 27 |
| 3. | The Phenakistiscope | 54 |
| 4. | Disc of the Phenakistiscope | 55 |
| 5. | Solar Spectrum | Frontispiece |
| 6. | Absorption of Light by Sodium Vapour | ib. |
| 7. | Action of a Prism on the Solar Rays | ib. |
| 8. | The Recomposition of Light | 86 |
| 9. | Recomposition of Light by means of a Concave Mirror | 87 |
| 10. | Recomposition of Light by means of a number of Mirrors | 88 |
| 11. | Newton’s Disc | 89 |
| 12. | Newton’s Rings | 95 |
| 13. | Reflection from Plane Surfaces | 107 |
| 14. | Refraction | 108 |
| 15. | Experimental Proof of Refraction | ib. |
| 16. | The Effects of Plane Mirrors | 109 |
| 17. | Reflection from the Surface of Water | 110 |
| 18. | Concave Mirror | 111 |
| 19. | Conjugate Foci | 113 |
| 20. | Virtual Focus | 114 |
| 21. | Concave Mirror | ib. |
| 22. | Magnifying Effect of Concave Mirrors | 115 |
| 23. | The Reversal of real Images | ib. |
| 24. | Diminishing Power of Convex Mirrors | 116 |
| 25. | Burning Mirror | 124 |
| 26. | Double Convex Lens | 127 |
| 27. | Forms of Lenses | 128 |
| 28. | Path of a Ray through a Convex Lens | 129 |
| 29. | Path of Divergent Rays through a Convex Lens | ib. |
| 30. | Conjugate Foci | 130 |
| 31. | Images formed by Convex Lenses | 131 |
| 32. | Magnifying Property of Convex Lenses | 132 |
| 33. | Diminishing Effect of Concave Lenses | ib. |
| 34. | Cannon of the Palais Royal | 134 |
| 35. | Fresnel’s Lighthouse Apparatus | 136 |
| 36. | Lantern of a First-Class Lighthouse | 140 |
| 37. | The Compound Microscope | 143 |
| 38. | The Theory of the Compound Microscope | 144 |
| 39. | Photo-Electric Microscope | 147 |
| 40. | Solar Microscope | 148 |
| 41. | The Galilean Telescope | 155 |
| 42. | The Astronomical Telescope | 156 |
| 43. | Section of an Astronomical Telescope | 157 |
| 44. | Section of the Gregorian Telescope | 160 |
| 45. | Gregorian Telescope | 161 |
| 46. | Section of a Newtonian Telescope | 162 |
| 47. | Herschellian Telescope | 164 |
| 48. | Foucault’s Large Telescope | 169 |
| 49. | Foucault’s Small Telescope | 171 |
| 50. | Section of the Magic Lantern | 179 |
| 51. | Magic Lantern | 182 |
| 52. | The Phantasmagoria | 184 |
| 53. | The Phantascope | 185 |
| 54. | Phantasmagoria (Robertson) | 194 |
| 55. | Wizard Dance | 198 |
| 56. | Nostradamus and Marie de Médicis | 201 |
| 57. | The Arrangement of the Reversing Prism | 203 |
| 58. | The Goat Trick | 205 |
| 59. | How to see through a Brick | 207 |
| 60. | The Polemoscope | 210 |
| 61. | Protection against ill-natured People | 213 |
| 62. | 218 | |
| 63. | Anamorphosis | 220 |
| 64. | Effect of Cut Paper-work | 225 |
| 65. | Seditious Toys | 229 |
| 66. | Diorama | 234 |
| 67. | 237 | |
| 68. | Stereoscope | 238 |
| 69. | The Principle of the Refracting Stereoscope | 239 |
| 70. | The Camera Obscura | 243 |
| 71. | Section of Camera Lucida | 247 |
| 72. | The Spectre—an Optical Illusion | 269 |
| 73. | How to produce Spectres | 271 |
THE WONDERS OF OPTICS.
PART I.
THE PHENOMENA OF VISION.