CONTENTS

PREFACE . . . . . . . . . . . . . . . v
INTRODUCTION . . . . . . . . . . . . . . xxi

BOOK I

[METEORS, HALO, RAINBOW, MOCK SUN, ETC.]

PREFACE

PAGE

CONTRAST between human (moral) philosophy and divine (natural, physical). The sublime character of the latter, which lifts us above the contemplation of the trivialities of the earth and earthly life to the knowledge of God and His nature. Compared with astronomical conceptions and dimensions, the world of man is but as a threshing-floor, the haunt of ants. The mind of man attains its true height in contemplation and investigation of these sublime facts. Some of the problems thus raised. . . . . . 3

CHAP.

I. Meteoric fires—she-goat, kid, etc. Occasions of their appearance; connection of portents with events. Explanation of the phenomena. They may be due to pressure of the atmosphere. Aristotle attributes them to the effect of terrestrial evaporation: difference of density causes various outbursts of this kind. They are analogous to lightning, but less violent. . . . . . 8

II. Halos. Produced by the light of a heavenly body striking the surrounding air and forming a circle, as a stone does when thrown into a pond. Formed far away from the heavenly body and comparatively near the earth in the region of the wind. Require a particular state of the atmosphere—neither too dense nor too thin. More frequent at night than by day for this reason: by day, the sun rarefies the air too much by its heat. Method of dissipation gives an indication of wind or rain. Calmness is a condition of formation, as in the analogous case of water. . . . . . 12

III. Rainbows. Generally by day, produced by inequalities of surface and density in clouds. Another species seen in a burst pipe or a fuller at work. Various explanations. Light and shade will not explain the varied colors. Some explain the rainbow as a confused reflection of the sun from individual drops of rain: every bounded surface, large or small, thus reflects—fish-pond and dew-drop equally. Aristotle attributes the confusion of colors to the weakness of human sight; parallels may be found in persons whose sight is abnormally weak. As the innumerable drops,