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CONTENTS. 



METEORIC STONES AND SHOOTING STARS. 



PAGE 



(/HAP. I. 1. Necessity of following out the true spirit of the induc- 

 tive philosophy in the investigation of physical phenomena. 2. 

 Circumstances attending appearance of meteorites supplied by past 

 observation Ball-lightning Explosive clouds Chladni's cata- 

 logue of meteoric stones. 3. Remarkable falls of aerolites. 4. 

 Physical condition and analysis of aerolites. 5. Crust of meteor- 

 ites, their internal mass. 6. Their magnitude and velocity. 7. 

 The different hypotheses or theories proposed to explain them. 

 8. Luminous appearance explained. 9. Hypothesis of Poisson. 



10. Atmospheric origin impossible. 11. Volcanic origin inadmis- 

 sible. 12. Lunar origin rejected. 13. Planetary origin generally 

 admitted. 14. Remarkable appearances of shooting-stars re- 

 corded in history. 15. Shower of stars seen in 1788 and 1799. 

 16. Also in 1822 and 1831. 17. Remarkable shower in 1833. 

 18. Vast number of shooting- stars seen on that occasion. 19. 

 Their magnitude 129 



CHAP. II. 1. Encke's calculation of the direction of the shooting-stars" 

 seen from 1833 to 1838. 2. Apparent magnitudes of those 

 objects. 3. The luminous train which follows them not an 

 optical illusion. 4. Hypotheses to explain them. 5. Heights, 

 directions, and velocity of shooting-stars, calculated by Brandes. 

 6. A like calculation by Quetelet. 7. A like calculation by 

 Wartmann. 8. Shooting-stars and fire-balls identical. 9. Lunar 

 origin rejected. 10. Received explanation of the phenomena. 



11. Difficulties and objections. 12. Description of great shower 

 of stars witnessed in 1799 by Hurnboldt and Bonpland. 

 13. Description of like showers in 1833-40. 14. August 

 meteors. 15. Halley suggests the use of these meteors to deter- 

 mine the longitude. 16. Table of shooting-stars from 763 to 

 1837. 17. Inferences from this. 18. Observation of Sir J. 

 Herschel in 1836. 19. Of Wartmann in 1837. 20. Of Tharand 

 in 1832. 21. Annual epochs of the prevalence of these meteors. 

 22. Why those masses are not visible like the moon and 

 planets by the reflected light of the sun. 23. Zodiacal light. 

 24. The nebulous matter producing it may cause shooting-stars. 

 2 5. ^ Shooting-stars may become satellites to the earth. 26. M. 

 Petit claims to have discovered one. 27. Sun-stones. ' . 145 



RAILWAY ACCIDENTS. 



CHAP. I. 1. All travelling attended with danger. 2. Awful disasters 

 incidental to railway travelling. 3. Is railway travelling, how- 

 ever, really more dangerous ? 4. Not practically so considered. 

 5. The real amount of danger may be calculated. 6. Utility 

 of such a calculation. 7. Imperfections of official reports. 8. 

 Necessary to compare accidents with total amount of travelling. 



