CONTENTS. XI 



SECTION X. 



Rotation of the Earth invariable Decrease in the Earth's mean Temperature 

 Earth originally in a state of Fusion Length of Day constant Decrease 

 of Temperature ascribed by Sir John Herschel to the Variation in the Ex- 

 centricity of the Terrestrial Orbit Difference in the Temperature of the two 

 Hemispheres, erroneously ascribed to the Excess in the Length of Spring 

 and Summer in the Southern Hemisphere; attributed by Mr. Lyell to the 

 Operation of existing Causes Three principal Axes of Rotation Position 

 of the Axis of Rotation on the Surface of the Earth invariable Ocean not 

 sufficient to restore the Equilibrium of the Earth if deranged Its Density 

 and mean Depth Internal Structure of the Earth . . .Page 80 



SECTION XI. 



Precession and Nutation Their Effects on the Apparent Places of the 

 Fixed Stars . . 89 



SECTION XII. 



Mean and Apparent Sidereal Time Mean and Apparent Solar Time 

 Equation of Time English and French Subdivisions of Time Leap Year 

 Christian Era Equinoctial Time Remarkable Eras depending upon 

 the Position of the Solar Perigee Inequality of the Lengths of the Seasons 

 in the two Hemispheres Application of Astronomy to Chronology 

 English and French Standards of Weights and Measures ... 93 



SECTION XIII. 



Tides Forces that produce them Three kinds of Oscillations in the Ocean 

 The Semidiurnal Tides Equinoctial Tides Effects of the Declination 

 of the Sun and Moon Theory insufficient without Observation Direction 

 of the Tidal Wave Height of Tides Mass of Moon obtained from her 

 Action on the Tides Interference of Undulations Impossibility of a 

 Universal Inundation Currents . 102 



SECTION XIV. 



Repulsive Force Interstices or Pores Elasticity Mossotti's Theory Gravi- 

 tation brought under the same Law with Molecular Attraction and Repul- 

 sion Gases reduced to Liquids by Pressure Intensity of the Cohesive 

 Force Effects of Gravitation Effects of Cohesion Minuteness of the 

 ultimate Atoms of Matter Limited Height of the Atmosphere Theory 

 of Definite Proportions and Relative Weight of Atoms Dr. Faraday's Dis- 

 coveries with regard to Affinity Composition of Water by a Plate of Platina 

 Crystallisation Cleavage Isomorphism Matter consists of Atoms of de- 

 finite Form Capillary Attraction 114 



