earlier in date than the latter. Some of the
development-sequences may in reality be contemporary with others instead
of earlier, and allowance must always be made for aberrations and
reversions to earlier types.

This caveat having been entered, however, we may provisionally
accept Prof. Petrie's system of sequence-dating as giving the best
classification of the prehistoric antiquities according to development.
So it may fairly be said that, as far as we know, the black and red
pottery ("sequence-date 30--") is the most ancient Neolithic Egyptian
ware known; that the buff and red did not begin to be used till about
"sequence-date 45;" that bone and ivory carvings were commonest in the
earlier period ("sequence-dates 30-50"); that copper was almost unknown
till "sequence-date 50," and so on. The arbitrary numbers used range
from 30 to 80, in order to allow for possible earlier and later
additions, which may be rendered necessary by the progress of discovery.
The numbers are of course as purely arbitrary and relative as those
of the different thermometrical systems, but they afford a convenient
system of arrangement. The products of the prehistoric Egyptians are, so
to speak, distributed on a conventional plan over a scale numbered from
30 to 80, 30 representing the beginning and 80 the close of the term,
so far as its close has as yet been ascertained. It is probable that
"sequence-date 80" more or less accurately marks the beginning of the
dynastic or historical period.

This hypothetically chronological classification is, as has been said,
due to Prof. Petrie, and has been adopted by Mr. Randall-Maclver and
other students of prehistoric Egypt in their work. [*_El Amra and
Abydos_, Egypt Exploration Fund, 1902.] To Prof. Petrie then is due the
credit of systematizing the study of Egyptian prehistoric antiquities;
but the further credit of having _discovered_ these antiquities
themselves and settled their date belongs not to him but to the
distinguished French archaeologist, M. J. de Morgan, who was for several
years director of the museum at Giza, and is now chief of the French
archaeological delegation in Persia, which has made of late years so many
important discoveries. The proof of the prehistoric date of this class
of antiquities was given, not by Prof. Petrie after his excavations at
Dendera in 1897-8, but by M. de Morgan in his volume, _Recherches sur
les Origines de l'Egypte: l'Age de la Pierre et les Metaux_,