is marked on the map, as a hill
top, and read the barometer. This will give the correction to be made
to all the previous notes. If there is no level recorded, get down to
a stream bed (the larger the better) and read it there, recording the
exact place on the map. The level may then be worked out
approximately by points above and below on the stream, for accurate
reading, hold the aneroid face up, gently tap it, and read; then face
down similarly, and take the mean. Guard that the wind does not blow
against any keyhole in the case.

Pencil all levels and localities on flints as soon as found. Ink in
the notes on the least prominent parts of the flint, in small capital
letters, when in camp, with waterproof China ink.

Styles of flint work.
The Eoliths are worn pebbles, chipped as if for scraping. The Rostro-
carinate flints found at the base of the Crag are long bars with a
beak-end, suited for breaking up earth. The human origin of both of
these classes is contested. Flints of Strepy type are nodular and
partly trimmed into cutting edges, the smooth surface being left as a
handle. The Chelles types are remarkable for regularity and fine bold
flaking; the worn butt (though best for handling) was eventually
flaked away to obtain an artistic uniform finish. The St. Acheul
series has finer flaking, the crust being completely removed: there
is a tendency to ovate or almond shapes, and the edges are often
curved, the reverse S-curve being preferred, They diminish in size
towards the end of the period. The Chelles and St. Acheul series are
core implements, made by detaching flakes; and the succeeding (Le
Moustier) method is to use the flakes, generally for scraping. The
LA, EM the diagram is transitional from St. Acheul to Le Moustier.
The form marked M is the predecessor of the Solutrean form next below
it. The Aurignacian is a smaller flake industry, with many lumps more
or less conical, and often with careful parallel flaking or fluting.
The Solutre culture brought in a new style, particularly thin blades
with delicate surface flaking which seems to have reappeared in the
late Neolithic. The pointed borers, certain arrow-heads and minutely
chipped rods of flint are characteristic of the period, and flints of
this age are found on the Egyptian and Syrian deserts. Longer blades,
sometimes very coarse, with ends worn by scraping, mark the period of
La Madeleine. They are found in prehistoric Egyptian graves, along
with Ne