BOOK IV

CONTAINING A DISCUSSION OF SNOW, HAIL, AND RAIN. [THE NILE]

PREFACE

The dangers of flattery and its insidiousness. If you must have praise, praise yourself. Lucilius has good cause: he must not, however, think too much of himself because he is governor of that historic province Sicily, which has ere now decided the fate of generals and of empire 159

I. Leaving Sicily and its marvels let us deal with the omitted part of the last book, the Nile. There is no real analogy between it and the Danube 166

II. The course of the Nile; its cataracts. The inundation of the river. Its meaning to Egypt. Its denizens; crocodiles and dolphins in conflict. Causes of the overflow: melting of snow; Etesian Winds; drying up of the springs through internal heat of the earth in winter; the attraction of the sun in Africa draws water from the sea to fill up the gap caused by evaporation [none of the accounts apparently accepted] 167

III. Origin of hail; why it differs from snow 177

IV. Causes of snow in winter, hail in spring 179

V. It is said that the cooler air of the North (Scythia, etc.) is stirred by the melting of the snow in spring and floats South, causing hail instead of rain 180

VI. Hail, it is again alleged, is averted by sacrifice. If there is not a victim handy you have merely to prick your finger! 181

VII. This belief in the power of blood was an ancient superstition 182

VIII. Three causes why the air near the earth is warmest, and therefore produces snow rather than hail 182

IX. Democritus’ view--dense bodies are heated most quickly, and retain their heat longest 183

X. The air nearest the earth is denser than elsewhere 184

XI. The tops of mountains, it is urged, should be warmer because nearer the sun. The difference is wholly inappreciable if we adopt the scale of the universe, the true one 184

XII. The comparatively mild air near the earth causes snow, but not hail 186

XIII. The despicable luxury of the effeminate Romans, who bought snow, bathed in it, and must resort even to ice to cool the unnatural feverish thirst born of their indulgence 186