1. The Galilean Telescope 7 2. Royal Observatory, Greenwich, in Flamsteed’s time 8 3. Sir Isaac Newton 10 4. Gregorian Telescope 10 5. Cassegrainian Telescope 11 6. Newtonian Telescope 11 7. Common Refracting-Telescope 12 8. Le Mairean or Herschelian Telescope 13 9. 10-inch Reflecting-Telescope on a German Equatoreal, by Calver 17 10. Lord Rosse’s 6-foot Reflecting-Telescope 22 11. Refracting-Telescope, by Browning 32 12. “The Popular Reflector,” by Calver 40 13. 3-inch Refracting-Telescope, by Newton & Co. 41 14. Huygens’s Negative Eyepiece 46 15. Ramsden’s Positive Eyepiece 47 16. Berthon’s Dynamometer 50 17. Cooke and Sons’ Educational Telescope 52 18. Refracting-Telescope on a German Equatoreal 67 19. The Author’s Telescope: a 10-inch With-Browning Reflector 77 20. Sun-spot of June 19, 1889 95 21. Solar Eclipses visible in England, 1891 to 1922 98 22. Total Solar Eclipse of August 19, 1887 98 23. Belts of Sun-spots, visible Oct. 29, 1868 104 24. Shadows cast by Faculæ 109 25. Light-spots and streaks on Plato, 1879-82. (A. Stanley Williams.) 126 26. Petavius and Wrottesley at Sunset. (T. Gwyn Elger.) 129 27. Birt, Birt A, and the Straight Wall. (T. Gwyn Elger.) 130 28. Aristarchus and Herodotus at Sunrise. (T. Gwyn Elger.) 132 29. Mercury as a Morning Star 143 30. Venus as an Evening Star 150 31. Mars, 1886, April 13, 9^h 50^m 157 32. Orbits of the Satellites of Mars 159 33. Jupiter, as drawn by Dawes and others 178 34. Jupiter, 1886, April 9, 10^h 12^m 180 35. Occultation of Jupiter, Aug. 7, 1889 186 36. Jupiter and Satellites seen in a small glass 187 37. Shadows of Jupiter’s Satellites II. and III. 192 38. Saturn as observed by Cassini in August 1676 198 39. Saturn, 1885, Dec. 23, 7^h 54^m 201