savages that it is availed of frequently to immense advantage. The
most remarkable is by raising smokes, by which many important facts
are communicated to a considerable distance and made intelligible
by the manner, size, number, or repetition of the smokes, which
are commonly raised by firing spots of dry grass." (Josiah Gregg's
_Commerce of the Prairies_. _New York_, 1844, vol. ii, p. 286.)

The highest elevations of land are selected as stations from which
signals with smoke are made. These can be seen at a distance of from
twenty to fifty miles. By varying the number of columns of smoke
different meanings are conveyed. The most simple as well as the most
varied mode, and resembling the telegraphic alphabet, is arranged by
building a small fire, which is not allowed to blaze; then by placing
an armful of partially green grass or weeds over the fire, as if to
smother it, a dense white smoke is created, which ordinarily will
ascend in a continuous vertical column for hundreds of feet. Having
established a current of smoke, the Indian simply takes his blanket
and by spreading it over the small pile of weeds or grass from which
the smoke takes its source, and properly controlling the edges and
corners of the blanket, he confines the smoke, and is in this way able
to retain it for several moments. By rapidly displacing the blanket,
the operator is enabled to cause a dense volume of smoke to rise, the
length or shortness of which, as well as the number and frequency of
the columns, he can regulate perfectly, simply by a proper use of the
blanket. (Custer's _My life on the Plains_, _loc. cit._, p. 187.)

They gathered an armful of dried grass and weeds, which were placed
and carried upon the highest point of the peak, where, everything
being in readiness, the match was applied close to the ground; but
the blaze was no sooner well lighted and about to envelop the entire
amount of grass collected than it was smothered with the unlighted
portion. A slender column of gray smoke then began to ascend in a
perpendicular column. This was not enough, as it might be taken for
the smoke rising from a simple camp-fire. The smoldering grass was
then covered with a blanket, the corners of which were held so closely
to the ground as to almost completely confine and cut off the column
of smoke. Waiting a few moments, until the smoke was beginning to
escape from beneath, the blanket was suddenly thrown aside, when a
beautiful balloon-shape