n
connected with its continued burning, or whether from economic reasons
it became a sacred matter, has never been determined. The custom that
a fire should never go out upon the altar, and that it should be
carried in migrations from place to place, would seem to indicate that
these two motives were closely allied, if not related in cause and
effect.

{90}

Evidently, fire was used for centuries before man invented methods of
reproducing it. Simple as the process involved, it was a great
invention; or it may be stated that many devices were resorted to for
the creation of artificial fire. Perhaps the earliest was that of
rubbing two pieces of dry wood together, producing fire by friction.
This could be accomplished by persistent friction of two ordinary
pieces of dry wood, or by drilling a hole in a dry piece of wood with a
pointed stick until heat was developed and a spark produced to ignite
pieces of dry bark or grass. Another way was to make a groove in a
block of wood and run the end of a stick rapidly back and forth through
the groove. An invention called the fire-drill was simply a method of
twirling rapidly in the hand a wooden drill which was in contact with
dry wood, or by winding a string of the bow several times around the
drill and moving the bow back and forth horizontally, giving rapid
motion to the drill.

As tribes became more advanced, they used two pieces of flint with
which to strike fire, and after the discovery of iron, the flint and
iron were used. How many centuries these simple devices were essential
to the progress and even to the life of tribes, is not known; but when
we realize that but a few short years ago our fathers lighted the fire
with flint and steel, and that before the percussion cap was invented,
the powder in the musket was ignited by flint and hammer, we see how
important to civilization were these simple devices of producing fire
artificially. So simple an invention as the discovery of the friction
match saved hours of labor and permitted hours of leisure to be used in
other ways. It is one of the vagaries of human progress that a simple
device remains in use for thousands of years before its clumsy method
gives way to a new invention only one step in advance of the old.

_Cooking Added to the Economy of the Food Supply_.--Primitive man
doubtless consumed his food raw. The transition of the custom of
uncooked food to cooked food must have been gradual. We only know