book, "Elements of Navigation," the text of which was
followed closely in discussing Variation and Deviation and Traverse
Sailing.

I desire to express my gratitude to Lieutenant Commander R. T. Merrill,
2nd, U. S. N., for suggesting a detailed outline of the whole course; to
Lieutenant Commander B. O. Wills, U. S. N., for his valuable criticisms
and almost daily help during the preparation of these Lectures; to
Lieutenant (j. g.) C. D. Draper, U. S. N. R. F.; Lieutenant (j. g.) R.
Brush, U. S. N. R. F., and Lieutenant (j. g.) P. C. McPherson, U. S. N.
R. F., for many criticisms and suggestions; and to Captain Huntington,
Seamen's Church Institute, for suggesting helpful diagrams, particularly
the one on page 44. This opportunity is also taken for thanking the many
Instructors in the School for their opinions on various questions that
have come up in connection with the course and for assistance in
eliminating errors from the text.

E. G. D.

LIST OF BOOKS CONSULTED

AMERICAN PRACTICAL NAVIGATOR, BOWDITCH

NAVIGATION AND COMPASS DEVIATIONS, MUIR

NAUTICAL SCIENCE, POOR

ELEMENTS OF NAVIGATION, HENDERSON

WRINKLES IN PRACTICAL NAVIGATION, LECKY

WHYS AND WHEREFORES OF NAVIGATION, BRADFORD

EPITOME OF NAVIGATION, NORIE

NAVIGATION, HOSMER

FINDING A SHIP'S POSITION AT SEA, SUMNER

GENERAL ASTRONOMY, YOUNG

PREFACE

TO THOSE TAKING THIS COURSE IN NAVIGATION:

These lectures have been written with the idea of explaining, in as
simple language as possible, the fundamental elements of Navigation as
set forth in Bowditch's American Practical Navigator. They will be given
you during the time at the Training School devoted to this subject. At
present this time includes two morning periods of one and a half hours
each, separated by a recess of fifteen minutes. In general the plan is
to devote the first period to the lecture and the second period to
practical work.

Not many examples for practical work have been included in this book,
but one example, illustrating each new method, has been worked out. If
you understand these examples you should be able to understand others
similar to them.

Toward the end of the course a portion of each second period will be
devoted to handling the sextant, work with charts, taking sights, etc.
In short, every effort will be made to duplicate, as nearly as possible,
navigating conditions on board a modern merchant ship.

DEPARTMENT OF NAVIGATION,

_Offi