s. When he meets an unusual word like
_mandatory_, he must not be content to guess at its significance by
linking it with _command_ and _mandate_, for as used in international
affairs it means something quite definite. To secure this complete
understanding of all his reading he will consult consistently every
book of reference. He should read with a good dictionary at his elbow,
and an atlas and an encyclopedia within easy reach. If he is able to
talk over with others what he reads, explaining to them what is not
clear, he will have an excellent method of testing his own
understanding. The old-fashioned practice of "saying lessons over" at
home contributed to this growth of a pupil's understanding.

Selecting. Third, the reader for material must know how to select. As
he usually reads to secure information or arguments for a certain
definite purpose, he will save time by knowing quickly what not to
read. All that engages his attention without directly contributing to
his aim is wasting time and energy. He must learn how to use books. If
he cannot handle alphabetized collections quickly he is wasting time.
If he does not know how material is arranged he will waste both time
and energy. He must know books.

Every printed production worthy of being called a book should have an
index. Is the index the same as the table of contents? The table of
contents is printed at the beginning of the volume. It is a synopsis,
by chapter headings or more detailed topics, of the plan of the book.
It gives a general outline of the contents of the book. You are
interested in public speaking. You wonder whether a book contains a
chapter on debating. Does this one? You notice that a speaker used a
series of jerky gesticulations. You wonder whether this book contains
a chapter upon gestures. Does it?

The table of contents is valuable for the purposes just indicated. It
appears always at the beginning of a work. If the work fills more than
one volume, the table of contents is sometimes given for all of them
in the first; sometimes it is divided among the volumes; sometimes
both arrangements are combined.

The table of contents is never so valuable as the index. This always
comes at the end of the book. If the work is in more than one volume
the index comes at the _end of the last volume_. What did you learn of
the topic _gestures_ in this book from your reference to the table of
contents? Now look at the index. What does the index do for a