Fig. 4. 



LE VERRIER AND ADAMS' PLANET. 



1. Surprise excited by the discovery. 2. How a body may be discovered 

 without seeing it. 3. Generalisation of the principle. 4. Its appli- 

 cation to the case of Neptune. 5. Condition of the solar system 

 before the discovery. 6. Observed disturbances of Uranus. 7. Great 

 regularity of these effects. 8. How they would be produced by a 

 more distant planet. 9. Calculations of Le Verrier and Adams. 

 10. Elements of the sought planet according to these geometers. 

 11. Its actual discovery. 12. Its corrected elements. 13. Dis- 

 crepancies between the actual and predicted elements explained. 

 14. Comparison of the effects of the real and predicted planets. 

 15. The discovery not to be ascribed to chance. 16. The period ot 

 Neptune computed. 17. Computation of his distance. 18. Its pro- 

 digious orbital motion. 19. Illustrated by a railway train. 20. Its 

 magnitude. 21. Its satellite. 22. Its weight. 23. Its bulk. 24. 

 The sun's light and heat upon it. 25. The sun's apparent diameter 

 seen from it. 26. Its suspected ring. 



1. THE universal astonishment which was excited some years 

 ago by the announcement that certain astronomers, whose names 



171 



