OF NEWTON'S "PRINCIPIA" { 175
61-2. } { 175

63. PRISMATIC DISPERSION 182

64. A SINGLE CONSTITUENT OF WHITE LIGHT IS CAPABLE OF NO
MORE DISPERSION 183

65. PARALLEL BEAM PASSING THROUGH A LENS 184

66. NEWTON'S TELESCOPE 186

67. THE SEXTANT, AS NOW MADE 187

68. NEWTON WHEN YOUNG 196

69. SIR ISAAC NEWTON 200

70. ANOTHER "PRINCIPIA" DIAGRAM 207

71. WELL-KNOWN MODEL EXHIBITING THE OBLATE SPHEROIDAL
FORM AS A CONSEQUENCE OF SPINNING ABOUT A CENTRAL
AXIS 219

72. JUPITER 221

73. DIAGRAM OF EYE LOOKING AT A LIGHT REFLECTED IN A DISTANT
MIRROR THROUGH THE TEETH OF A REVOLVING WHEEL 238

74. FIZEAU'S WHEEL, SHOWING THE APPEARANCE OF DISTANT
IMAGE SEEN THROUGH ITS TEETH 239

75. ECLIPSES OF ONE OF JUPITER'S SATELLITES 241

76. A TRANSIT INSTRUMENT FOR THE BRITISH ASTRONOMICAL EXPEDITION,
1874 243

77. DIAGRAM OF EQUATORIALLY MOUNTED TELESCOPE 245

78. ABERRATION DIAGRAM 250

79. SHOWING THE THREE CONJUNCTION PLACES IN THE ORBITS OF
JUPITER AND SATURN 259

80. LORD ROSSE'S DRAWING OF THE SPIRAL NEBULA IN CANES
VENATICI 269

81. SATURN 271

82. PRINCIPLE OF NEWTONIAN REFLECTOR 278

83. HERSCHEL'S 40-FOOT TELESCOPE 283

84. WILLIAM HERSCHEL 285

85. CAROLINE HERSCHEL 287

86. DOUBLE STARS 288