Chap. 1. Summary of subject-matter of meteorology. 2. The material and the efficient cause of the phenomena to be studied. 3. The position of air and fire relatively to the celestial sphere. Why clouds and water do not form in ether. 4. The cause of shooting-stars and the like. 5. The cause of the appearance of 'chasms &c., in the sky. 6. Refutation of earlier theories of comets. 7. The cause of comets. 8. The milky way. 9. The causes of rain, and the difi'erence between cloud and mist. 10. The causes of dew and boar-frost. II. The causes and concomitants of snow. 12. Hail-where and when it is produced. 13. Winds, rivers, and springs. I4. Why the same parts of the earth are not always watered by rivers, or always dry. Floods.