(6) The nuances between the different _d_, _h_, _k_, _t_, and _s_
sounds.

3. Surface-exploration of a tell.
The stratification can rarely be studied on the surface only:
superficial indications of this are obscured by the plough, weather,
vegetation, and the activities of modern natives who grub for
building-stone and for the chance of buried treasure. Only by
trenching can the strata be exposed. An exception to this rule is
afforded by _Tell el-Hesy_ (Lachish) explored by Dr. Petrie in 1890-
1: here the erosion of a stream had exposed enough of the strata for
a reconnaissance. In the majority of cases the most that a visitor
can hope to do is to pick up stray antiquities on the surface of the
ground, and ascertain therefrom the limits of date.

The chief clue is afforded by the pottery (see below, V), sherds of
which, large and small, are strewn in considerable numbers on every
ancient site. Scarabs, seals, bronze implements, iron fragments,
beads, bone ornaments, and the like may also be noticed. A trained
eye is essential even for such surface finds: one man may walk over a
mound and find nothing, another may walk in his steps and gather
quite an interesting harvest of small objects.

Surface indications of buried buildings (or rather foundations) may
be noted both on the top and on the sides of a tell. Lines of wall
may not infrequently be traced. Often the vegetation growing on the
surface indicates the presence of structures underneath (either by
burnt-up patches amid luxuriant growths, or vice versa).

4. Surface exploration of a khirbet.