952 IN THE DESERT DELTA OF SISTAN [Chap. XXX
a whole series of ancient watch-stations constituting a Limes-like line drawn across the southern delta. Leaving a full account of it for section iv,_ I may at once explain that it was largely the search for the remains of this Limes which led to mÿ visiting other points of prehistoric occupation in this area. The ruined post R.R. iv stands on a low gravel-covered plateau, which shows practically no wind-erosion on its surface nor evidence of prehistoric occupation.
Finds at The surface of the ground showed much the same conditions at R.R. v (Fig. 479), a corn-
ruin R. R. v. paratively well preserved ruin of the Limes, about 3 miles to the NNE. Here early occupation was indicated by pottery debris of the chalcolithic type, which strewed the ground to the W. and N. of the ruined post, and significantly enough fragments of the same were found embedded in the bricks. The arrow-heads of jasper and chert, R.R. v. 09-10 (Pl. CXII), as well as the rim and side of a stone bowl, o6, are relics of the prehistoric settlement. But the piece of green-glazed pottery, 03, and the miscellaneous fragments of glass and paste named in the List obviously date from the time when the post was tenanted.
Prehistoric Proceeding ESE. from our camp at R.R. v for a mile and a half over the pebble-strewn
remains plain, at lain we reached the conspicuous mound R. R. vi. Here fragments of prehistoric pottery are
R.Rnds . VI, VII. abundant. Among them were found the stone arrow-heads R.R. vi. oi, 13-17 (Pl. CXII), and
pieces of lathe-turned alabaster vessels, 08-12. R.R. vii, about 2 miles farther in the same direction, is a typical Mesa (Fig. 5oo), rising with steep slopes to a height of about 25 feet above the gravelly plain. Here again the level ground around the foot of the mound was found thickly covered with prehistoric pottery, plain, painted, or incised, as shown by the specimens Pl. CXIII, CXV. Stone arrow-heads, R.R. vii. 024-6, are shown in Pl. CXII.
Chalcolithic Turning thence to the SW., I found within less than a mile a small cluster of Mesas, R. R.
remains at all three about 20 feet in height, and plentifully strewn with remains of chalcolithic culture,
in the shape of potsherds, plain or painted, as shown by the specimens in Pl. CXIII. Another
mound, R.R. xi, a mile farther on, yielded, besides stone arrow-heads (R. R. xi. 015-16, Pl. CXII) and fragments of alabaster jars or bowls, the bronze seal in relievo, R.R. xi. 014 (Pl. CXVI), with an interesting ornamental device. Continuing for i miles in the same direction, I came upon the remains of a fortified post, R.R. XII (Fig. 492), and recognized in it a replica, badly decayed, of the ruin R.R. iv. Fragments of prehistoric pottery strewing the ground close by and also embedded in the bricks of the ruin clearly showed that this fort had been built on the site of a far older chalcolithic settlement. To this belonged also the pieces of alabaster vessels picked up here, while the iron knife, R.R. xii. 037, Pl. CXVI, manifestly dates from the later occupation of the spot.
On visiting the ruin next sighted, R.R. XII. a, that of a post somewhat smaller but built on a similar plan about a mile to SSE., I found that it, too, rose on a mound bearing relics of chalcolithic age. Finding the same conditions repeated in the ruined watch-posts which I subsequently examined while tracing the border line to the NW. of R.R. iv, I soon recognized the reason for the significant association with these ruins of relics of a civilization far more ancient. The mounds which the debris deposits of that early occupation had protected from wind-erosion already rose well above the surrounding country at the time when this defensive line was built across the southern delta. They thus naturally offered themselves as the most suitable positions for the chain of fortified stations designed to protect the cultivated area to the north against nomadic raids ; for they had the advantage of commanding a wider outlook.
This was certainly the case at the site of R.R. xvii, about i 2 miles to the SSW. of R.R. v, where a small castrum with a central fort (Fig. 485 ; Pl. 59) was located. Here prehistoric painted pottery and fragments of alabaster cups were plentiful outside the enclosure, while within it the potsherds were mainly coarser plain ware. The ruined watch-station R.R. xvi, about i miles from R. R.