y with duplicating sheets. The regulation envelope
is three by five and one-fourth inches and is printed as follows:

UNITED STATES ARMY FIELD MESSAGE.

_To_ . . . . . . . . . . . . . . . . . . . . ._No_ . . . .
(For signal operator only.)
_When_sent_ . . . . . . . . . . . . . . . . ._No_ . . . .
_Rate_of_speed_ . . . . . . . . . . . . . . . . . . . . .
_Name_of_messenger_ . . . . . . . . . . . . . . . . . . .
_When_and_by_whom_rec'd_ . . . . . . . . . . . . . . . . .
This Envelope will be Returned to Bearer.

[Illustration]

CHAPTER XII.

SIGNALS AND CODES.

(Extracts from Signal Book, United States Army, 1916.)

General Instructions for Army Signaling.

1. Each signal station will have its call, consisting of one or
two letters, as Washington, "W"; and each operator or signalist
will also have his personal signal of one or two letters, as
Jones, "Jo." These being once adopted will not be changed without
due authority.

2. To lessen liability of error, numerals which occur in the body
of a message should be spelled out.

3. In receiving a message the man at the telescope should call
out each letter as received, and not wait for the completion
of a word.

4. A record of the date and time of the receipt or transmission
of every message must be kept.

5. The duplicate manuscript of messages received at, or the original
sent from, a station should be carefully filed.

6. In receiving messages nothing should be taken for granted,
and nothing considered as seen until it has been positively and
clearly in view. Do not anticipate what will follow from signals
already given. Watch the communicating station until the last
signals are made, and be very certain that the signal for the
end of the message has been given.

7. Every address must contain at least two words and should be
sufficient to secure delivery.

8. All that the sender writes for transmission after the word
"To" is counted.

9. Whenever more than one signature is attached to a message count
all initials and names as a part of the message.

10. Dictionary words, initial letters, surnames of persons, names
of cities, towns, villages, States, and Territories, or names of
the Canadian Provinces will be counted each as one word: _e._g._,
New York, District of Columbia, East St. Louis should each be
counted as one word. The abbreviation of the names of cities,