| FIG. |
|
PAGE |
| |
| 1. |
The heavens according to Ptolemy |
3 |
| |
| 2. |
The zodiac of Denderah |
7 |
| |
| 3. |
Illustration of Euclid’s statements |
10 |
| |
| 4. |
The plane of the ecliptic |
13 |
| |
| 5. |
The plane of the ecliptic, showing the inclination of the earth’s axis |
14 |
| |
| 6. |
The first meridian circle |
20 |
| |
| 7. |
The first instrument graduated into 360° (west side) |
21 |
| |
| 8. |
Astrolabe (armillæ æquatoriæ of Tycho Brahe) similar to the one contrived by Hipparchus |
26 |
| |
| 9. |
Ecliptic astrolabe (the armillæ zodiacales of Tycho Brahe), similar to the one used by Hipparchus |
28 |
| |
| 10. |
Diagram illustrating the precession of the equinoxes |
31 |
| |
| 11. |
Revolution of the pole of the equator round the pole of the ecliptic caused by the precession of the equinoxes |
32 |
| |
| 12. |
The vernal equinox among the constellations, B.C. 2170 |
34 |
| |
| 13. |
Showing how the vernal equinox has now passed from Taurus and Aries |
34 |
| |
| 14. |
Instrument for measuring altitudes |
35 |
| |
| 15. |
Portrait of Tycho Brahe (from original painting in the possession of Dr. Crompton, of Manchester) |
39 |
| |
| 16. |
Tycho Brahe’s observatory on the island of Huen |
43 |
| |
| 17. |
Tycho Brahe’s system |
46 |
| |
| 18. |
The quadrans maximus reproduced from Tycho’s plate |
48 |
| |
| 19. |
Tycho’s sextant |
50 |
| |
| 20. |
View and section of a prism |
56 |
| |
| 21. |
Deviation of light in passing at various incidences through prisms of various angles |
57 |
| |
| 22. |
Convergence of light by two prisms base to base |
59 |
| |
| 23. |
Formation of a lens from sections of prisms |
60 |
| |
| 24. |
Front view and section of a double convex lens |
61 |
| |
| 25. |
Double concave, plane concave, and concavo-convex lenses |
61 |
| |
| 26. |
Double convex, plane convex, and concavo-convex lenses |
62 |
| |
| 27. |
Convergence of rays by convex lens to principal focus |
62 |
| |
| 28. |
Conjugate foci of convex lens |
63 |
| |
| 29. |
Conjugate images |
64 |
| |
| 30. |
Diagram explaining Fig. 29 |
64 |
| |
| 31. |
Dispersion of rays by a double concave lens |
65 |
| |
| 32. |
Horizontal section of the eyeball |
66 |
| |
| 33. |
Action of eye in formation of images |
68 |
| |
| 34. |
Action of a long-sighted eye |
69 |
| |
| 35. |
Diagram showing path of rays when viewing an object at an easy distance |
70 |
| |
| 36. |
Action of short-sighted eye |
71 |
| |
| 37. |
Galilean telescope |
73 |
| |
| 38. |
Telescope |
75 |
| |
| 39. |
Diagram explaining the magnifying power of object-glass |
76 |
| |
| 40. |
Scheiner’s telescope |
78 |
| |
| 41. |
Dispersion of light by prism |
80 |
| |
| 42. |
Diagram showing the amount of colour produced by a lens |
81 |
| |
| 43. |
Decomposition and recomposition of light by two prisms |
83 |
| |
| 44. |
Diagram explaining the formation of an achromatic lens |
84 |
| |
| 45. |
Combination of flint- and crown-glass lenses in an achromatic lens |
86 |
| |
| 46. |
Diagram illustrating the irrationality of the spectrum |
87 |
| |
| 47. |
Diagram illustrating the action of a reflecting surface |
91 |
| |
| 48. |
Experimental proof that the angle of incidence = angle of reflection |
92 |
| |
| 49. |
Convergence of light by concave mirror |
94 |
| |
| 50. |
Conjugate foci of convex mirror |
94 |
| |
| 51. |
Formation of image of candle by reflection |
95 |
| |
| 52. |
Diagram explaining Fig. 51 |
96 |
| |
| 53. |
Reflection of rays by convex mirror |
98 |
| |
| 54. |
Reflecting telescope (Gregorian) |
101 |
| |
| 55. |
Newton’s telescope |
102 |
| |
| 56. |
Reflecting telescope (Cassegrain) |
103 |
| |
| 57. |
Front view telescope (Herschel) |
103 |
| |
| 58. |
Diagram illustrating spherical aberration |
105 |
| |
| 59. |
Diagram showing the proper form of reflector to be an ellipse |
106 |
| |
| 60. |
Huyghens’ eyepiece |
110 |
| |
| 61. |
Diagram explaining the achromaticity of the Huyghenian eyepiece |
111 |
| |
| 62. |
Ramsden’s eyepiece |
112 |
| |
| 63. |
Erecting or day eyepiece |
113 |
| |
| 64. |
Images of planet produced by short and long focus lenses, &c. |
123 |
| |
| 65. |
Showing in an exaggerated form how the edge of the speculum is worn down by polishing |
128 |
| |
| 65*. |
Section of Lord Rosse’s polishing machine |
131 |
| |
| 66. |
Mr. Lassell’s polishing machine |
132 |
| |
| 67. |
Simple telescope tube, showing arrangement of object-glass and eyepiece |
140 |
| |
| 68. |
Appearance of diffraction rings round a star when the object-glass is properly adjusted |
141 |
| |
| 69. |
Appearance of same object when object-glass is out of adjustment |
141 |
| |
| 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 separately |
148 |
| |
| 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 pressure |
194 |
| |
| 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 |
| |
| 108. |
Double images seen through Iceland spar |
227 |
| |
| 109. |
Diagram showing the ordinary and extraordinary rays in a crystal of Iceland spar |
227 |
| |
| 110. |
Crystals of Iceland spar |
228 |
| |
| 111. |
Double image micrometer |
229 |
| |
| 112. |
Tycho Brahe’s mural quadrant |
235 |
| |
| 113. |
Transit instrument (Transit of Venus Expedition) |
236 |
| |
| 114. |
Transit instrument in a fixed observatory |
237 |
| |
| 115. |
Diagram explaining third adjustment |
239 |
| |
| 116. |
The mural circle |
241 |
| |
| 117. |
Transit circle, showing the addition of circles to the transit instrument |
242 |
| |
| 118. |
Perspective view of Greenwich transit circle |
243 |
| |
| 119. |
Plan of the Greenwich transit circle |
245 |
| |
| 120. |
Cambridge (U.S.) meridian circle |
248 |
| |
| 121. |
Diagram illustrating how the pole is found |
249 |
| |
| 122. |
Diagram illustrating the different lengths of solar and sidereal day |
255 |
| |
| 123. |
System of wires in transit eyepiece |
257 |
| |
| 124. |
The Greenwich chronograph. (General view) |
261 |
| |
| 125. |
Details of the travelling carriage which carries the magnets and prickers. (Side view and view from above) |
262 |
| |
| 126. |
Showing how on the passage of a current round the soft iron the pricker is made to make a mark on the spiral line on the cylinder |
263 |
| |
| 127. |
Side view of the carriage carrying the magnets and the pointer that draws the spiral |
263 |
| |
| 128. |
Wheel of the sidereal clock, and arrangement for making contact at each second |
266 |
| |
| 129. |
Arrangement for correcting mean solar time clock at Greenwich |
268 |
| |
| 130. |
The chronopher |
276 |
| |
| 131. |
Reflex zenith tube |
286 |
| |
| 132. |
Theodolite |
288 |
| |
| 133. |
Portable alt-azimuth |
289 |
| |
| 134. |
The 40-feet at Slough |
294 |
| |
| 135. |
Lord Rosse’s 6-feet |
295 |
| |
| 136. |
Refractor mounted on alt-azimuth tripod for ordinary star-gazing |
296 |
| |
| 137. |
Simple equatorial mounting |
298 |
| |
| 138. |
Cooke’s form for refractors |
300 |
| |
| 139. |
Mr. Grubb’s form applied to a Cassegrain reflector |
301 |
| |
| 140. |
Grubb’s form for Newtonians |
303 |
| |
| 141. |
Browning’s mounting for Newtonians |
304 |
| |
| 142. |
The Washington great equatorial |
309 |
| |
| 143. |
General view of the Melbourne reflector |
312 |
| |
| 144. |
The mounting of the Melbourne telescope |
313 |
| |
| 145. |
Great silver-on-glass reflector at the Paris observatory |
316 |
| |
| 146. |
Clock governor |
319 |
| |
| 147. |
Bond’s spring governor |
320 |
| |
| 148. |
Foucault’s governor |
323 |
| |
| 149. |
Illuminating lamp for equatorial |
325 |
| |
| 150. |
Cooke’s illuminating lamp |
326 |
| |
| 151. |
Dome |
338 |
| |
| 152. |
Drum |
338 |
| |
| 153. |
New Cincinnati observatory—(Font elevation) |
338 |
| |
| 154. |
Cambridge (U.S.) equatorial |
339 |
| |
| 155. |
Section of main building—United States naval observatory |
341 |
| |
| 156. |
Foucault’s siderostat |
344 |
| |
| 157. |
The siderostat at Lord Lindsay’s observatory |
348 |
| |
| 158. |
Position circle |
353 |
| |
| 159. |
How the length of a shadow thrown by a lunar hill is measured |
354 |
| |
| 160. |
The determination of the angle of position of the axis of Saturn’s ring |
358 |
| |
| 161. |
Measurement of the angle of position of the axis of a figure of a comet |
359 |
| |
| 162. |
Double star measurement |
360 |
| |
| 163. |
Ring micrometer |
368 |
| |
| 164. |
Thermopile and galvanometer |
374 |
| |
| 165. |
Rumford’s photometer |
378 |
| |
| 166. |
Bouguer’s photometer |
379 |
| |
| 167. |
Kepler’s diagram |
387 |
| |
| 168. |
Newton’s experiment, showing the different refrangibilities of colours |
388 |
| |
| 169. |
First observation of the lines in the solar spectrum |
391 |
| |
| 170. |
Solar spectrum |
392 |
| |
| 171. |
Student’s spectroscope |
393 |
| |
| 172. |
Section of spectroscope |
394 |
| |
| 173. |
Spectroscope with four prisms |
396 |
| |
| 174. |
Automatic spectroscope (Grubb’s form) |
397 |
| |
| 175. |
Automatic spectroscope (Browning’s form) |
397 |
| |
| 176. |
Last prism of train for returning the rays |
398 |
| |
| 177. |
Spectroscope with returning beam |
399 |
| |
| 178. |
Direct-vision prism |
399 |
| |
| 179. |
Electric lamp |
404 |
| |
| 180. |
Electric lamp arranged for throwing a spectrum on a screen |
405 |
| |
| 181. |
Comparison of the line spectra of iron, calcium, and aluminium, with common impurities |
406 |
| |
| 182. |
Coloured flame of salts in the flame of a Bunsen’s burner |
408 |
| |
| 183. |
Spectroscope arranged for showing absorption |
409 |
| |
| 184. |
Geissler’s tube |
413 |
| |
| 185. |
Spectrum of sun-spot |
415 |
| |
| 186. |
Diagram explaining long and short lines |
416 |
| |
| 187. |
Comparison of the absorption spectrum of the sun with the radiation spectra of iron and calcium, with common impurities |
418 |
| |
| 188. |
Comparison prism |
423 |
| |
| 189. |
Comparison prism |
423 |
| |
| 190. |
Foucault’s heliostat |
424 |
| |
| 191. |
Object-glass prism |
426 |
| |
| 192. |
The eyepiece end of the Newall refractor |
427 |
| |
| 193. |
Solar telespectroscope (Browning’s form) |
428 |
| |
| 194. |
Solar telespectroscope (Grubb’s form) |
428 |
| |
| 195. |
Side view of spectroscope |
429 |
| |
| 196. |
Plan of spectroscope |
429 |
| |
| 197. |
Cambridge star spectroscope elevation |
430 |
| |
| 198. |
Cambridge spectroscope plan |
430 |
| |
| 199. |
Direct-vision star spectroscope (Secchi) |
431 |
| |
| 200. |
Types of stellar spectra |
433 |
| |
| 201. |
Part of solar spectrum near F |
436 |
| |
| 202. |
Distortions of F line on sun |
438 |
| |
| 203. |
Displacement of F line on edge of sun |
439 |
| |
| 204. |
Diagram showing the path of the ordinary and extraordinary ray in crystals of Iceland spar |
445 |
| |
| 205. |
Appearance of the spots of light on the screen shown in the preceding figure, allowing the ordinary ray to pass and rotating the second crystal |
446 |
| |
| 206. |
Appearance of spots of light on screen on rotating the second crystal, when the extraordinary ray is allowed to pass through the first screen |
447 |
| |
| 207. |
Instrument for showing polarization by reflection |
448 |
| |
| 208. |
Section of plate-holder |
456 |
| |
| 209. |
Enlarging camera |
458 |
| |
| 210. |
Instantaneous shutter |
460 |
| |
| 211. |
Photoheliograph as erected in a temporary observatory for photographing the transit of Venus in 1874 |
461 |
| |
| 212. |
Copy of photograph taken during the eclipse of 1869 |
474 |
| |
| 213. |
Part of Beer and Mädler’s map of the moon |
476 |
| |
| 214. |
The same region copied from a photograph by De La Rue |
477 |
| |
| 215. |
Comparison between Kirchhoff’s map and Rutherfurd’s photograph |
480 |
| |
| 216. |
Arrangement for photographically determining the coincidence of solar and metallic lines |
481 |
| |
| 217. |
Telespectroscope with camera for obtaining photographs of the solar prominences |
482 |
