Among the most interesting of these finds has been the
bringing to light of several tablets, one of which is preserved
in the Yale Babylonian Collection, and which constitute the
oldest human documents thus far discovered. These several
tablets are of black stone, of no very great size, but bear en-
graven on their surfaces characters which give to us a message
out of the past, the time of which antedates that of Christ by
some 5,500 to 6,000 years; in other words, a thousand or more
years before Doctor Lightfoot's date. Nor is this all, for the
inscriptions are no longer in the so-called picture writing or
ideographs, but in a form of writing undoubtedly derived from
this. They have progressed so far along an evolutionary path-
way that the original pictures cannot in some instances be even
guessed at. This, it would seem, implies a centuries-long de-
velopmental period before the beginning of inscriptive writ-
ings, and the inference is also justifiable that the protoscript
could not have been invented but by peoples of considerable
intellectual powers who had long since emerged from savagery
and were vastly further yet removed from their ultimate
beginnings.

The third line of evidence is cultural, based not on inscrip-
tions or documents of any sort, but upon the implements and
weapons of vanished peoples, with their varying degrees of
refinement. Historic times, as is well known, are often spoken
of as the Age of Iron, and perhaps the Age of Bronze, while
the prehistoric is called the Age of Stone. But the Stone Age
again has its subdivisions into, first, the New Stone Age or
Neolithic period, in which the distinctive characteristic of the
implements is that some of them at least were rubbed smooth
or polished after the preliminary fashioning was completed.
Back of this period lies the Paleolithic, varying immensely in
the degree of perfection of use and workmanship, so that
archeologists are agreed upon a number of cultures (see
table, infra ), based upon distinctions some of which are evident

-2-