69. Appearance of same object when object-glass is out of 141 adjustment 70. Optical part of a Newtonian reflector of ten inches aperture 143 71. Optical part of a Melbourne reflector 143 72. Mr. Browning’s method of supporting small specula 144 73. Support of the mirror when vertical 146 74. Division of the speculum into equal areas 147 75. Primary, secondary, and tertiary systems of levers shown 148 separately 76. Complete system consolidated into three screws 148 77. Support of diagonal plane mirror (Front view) 150 78. Support of diagonal plane mirror (Side view) 150 79. A portion of the constellation Gemini seen with the naked eye 154 80. The same region, as seen through a large telescope 155 81. Orion and the neighbouring constellations 156 82. Nebula of Orion 157 83. Saturn and his moons 160 84. Details of the ring of Saturn 161 85. Ancient clock escapement 177 86. The crown wheel 178 87. The clock train 180 88. Winding arrangements 181 89. The cycloidal pendulum 185 90. Graham’s, Harrison’s, and Greenwich pendulums 188 91. Greenwich clock: arrangement for compensation for barometric 194 pressure 92. The anchor escapement 197 93. Graham’s dead beat 199 94. Gravity escapement (Mudge) 200 95. Gravity escapement (Bloxam) 202 96. Greenwich clock escapement 204 97. Compensating balance 207 98. Detached lever escapement 208 99. Chronometer escapement 209 100. The fusee 209 101. Diggs’ diagonal scale 213 102. The vernier 214 103. System of wires in a transit eyepiece 220 104. Wire micrometer 221 105. Images of Jupiter 224 106. Object-glass cut into two parts 225 107. The parts separated, and giving two images of any object 225