Note 44, page 112: The smoke signal has been in use for many, many years. The Indians of the West used it much, and whenever an army detachment or other strangers traversed the plains and the hills their course was marked by the smoke signals of Indian scouts. To make smoke signals, first a moderate blaze is started; then damp or green stuff is piled on, for a smudge; and the column of smoke is cut into puffs by a blanket or coat held over like a cup and suddenly jerked off. A high place should be selected for the smoke signal, so as to distinguish it from the ordinary camp-fire, which is not as a rule made on a high place,—that is, in hostile country. A still day is necessary for accurate smoke signaling. This signaling is being recommended for the United States Forestry Service, so that Rangers and Guards can telegraph warnings and news by the Morse or the Army and Navy alphabet. A short puff would be the dot, a long puff the dash; or one short puff would be "1," two short puffs close together "2," and a long puff "3." This Army and Navy code is explained under Note 48.
The Indians had secret codes, for the smoke signals; and used dense smokes and thin smokes, both. Green pine and spruce and fire boughs raise a thick black smoke.
In army scouting on the plains the following signals were customary:
"Wish to communicate." Three smokes side by side.
"Enemy discovered." Two puffs, repeated at fifteen-minute intervals. Boy Scouts need not have the intervals so long. One minute is enough, for a standard.
"Many enemy discovered." Three puffs, at intervals.
"Come to council," or "Join forces." Four puffs, repeated.
"March to the north." Two smokes, of two puffs each.
"March to the south." Two smokes, of three puffs each.
"March to the east." Three smokes, of two puffs each.