x Introduction 
It is the purpose of this handbook to describe, list and 
explain some of the natural phenomena which may be ob- 
served at sea. Without being technical, we shall discuss 
many of the things that scientists have discovered about the 
sea and sky, and we shall touch upon such subjects as ocean- 
ography, geophysics, hydrodynamics, astronomy—all im- 
mense subjects in themselves. 
No one science can claim a monopoly over sea and sky. 
For example, there are physical phenomena in the form of 
waves, ocean currents, chemistry of sea water, submarine 
topography and icebergs. Then there is also a great world 
of ocean life: myriads of marine animals and plants and sea 
birds. In ocean meteorology there are such things as cy- 
clones, waterspouts, clouds, winds, St. Elmo's fire and sun- 
dogs. Under geophysics we will deal with submarine vol- 
canoes, the tides and terrestrial magnetism. We draw upon 
astronomy to describe the sun, the moon, the stars and other 
mysteries of the night sky. 
We commend to you, in this handbook, the results of 
many lifetimes of study and research, material gathered from 
all corners of the seven seas, and we hope that your in- 
terest in the strange antics of sea and sky will help while 
away many an otherwise empty, dull watch or evening 
ashore. 
HENRY STOMMEL 
