Every theory of the course of events in nature is necessarily based on some process of simplification of the phenomena and is to some extent therefore a fairy tale.

—SIR NAPIER SHAW
Manual of Meteorology: I, 123

Dedication

IN GRATITUDE FOR GENEROUS ASSISTANCE THIS BOOK IS DEDICATED TO

California Division of Highways

California Division of Water Resources

California Highway Patrol

City of Berkeley Police Department

Pacific Gas and Electric Company

Pacific Telephone and Telegraph Company

Pan American Airways Company

Southern Pacific Company

Transcontinental & Western Air, Inc

United Air Lines

United States Coast Guard

United States Engineers

United States Weather Bureau

University of California

Western Pacific Railroad Company

FIRST DAY

1

Enveloped in the gaseous film of the atmosphere, half-covered by a skim of water forming the oceans—the great sphere of the earth spun upon its axis and moved inflexibly in its course around the sun. Continuously, in the succession of day and night, season and season, year and year, the earth had received heat from the sun, and again lost into space that same amount of heat. But this balance of the entire sphere did not hold for its individual parts. The equatorial belt received yearly much more heat than it radiated off, and the polar regions lost much more heat than they received. Nevertheless the one was not growing hotter while the others sank toward absolute zero. Instead, at once tempering cosmic extremes and maintaining equilibrium with the sun, by a gigantic and complex circulation, the poles constantly cooled the tropics and the tropics reciprocally warmed the poles.

In this process, cold currents bore icebergs toward the equator, and warm currents moved poleward. But even these vast rivers of the oceans achieved only a small part of the necessary whole.

In the stupendous work of transport the paramount agent was the atmosphere, thin and insignificant though it was in comparison with the monstrous earth itself. Within the atmosphere the chief equalizers of heat were the great winds—the trades and anti-trades, the monsoons, the tropical hurricanes, the polar easterlies, and (most notable of all) the gigantic whirling storms of the temperate zones, which in the stateliest of earthly processions moved ever along their sinuous paths, across ocean and continent, from the setting toward the rising sun.

2

Early in November, had come “Election-Day rains.” Chilling after the warmth of October, low-lying clouds blew in from the southwest, thick with moisture from the Pacific. The golden-brown hills of the Coast Ranges grew darker beneath the downpour. In the Great Valley summer-dry creeks again ran water. Upon the Sierra the snow fell steadily. The six-month dry season was over.