RESEARCH AND DEVELOPMENT 55 
formerly flowed down the middle and deposited huge quantities 
of sand and silt and later changed its course to the west. The 
superficial sand dunes arise from fine material blown from coastal 
and desert regions of Sind and Rajasthan. 
The vegetation consists of low brush and scanty grass on which 
camels browse. There are no indications of early occupation, such 
as are found in other parts, prior to the fourteenth century, when 
a few tanks of about an acre each were constructed by the Em- 
peror Sher Shah Sun. 
The question of developing the Thal area was first considered 
in 1870. No action was taken until 1g0o1 when a Colonization Bill 
authorized the construction of a canal to the Shamlat area, but 
nothing was done until 1936 when the distribution of the waters 
of the Indus and its great tributaries was considered. Work on a 
Thal Project was begun in 1939 but was held up because of World 
War II, and channels were filled up with sand when in 1947 the 
flood of refugees from India moved into Pakistan. Of these 250,000 
are being settled in the Thal. 
In late August 1949 the Thal Development Authority was 
established, to be responsible for the full development of an area 
of 834,500 acres, with an area of 638,000 acres to be developed 
by private enterprise with the assistance of the Authority. 
It was believed that the agricultural development of the area 
and the establishment of villages and small towns throughout the 
area needed the balance of industrial development, and so today 
there are sugar mills, cotton textile mills, a woollen mill, and a 
cement factory in the area. Some 640 villages have been estab- 
lished, each with forty or fifty houses on a total of 100 acres, 
with a green belt all round each village and a timber area of 
50 acres alongside. 
Each settler is allowed 15 acres of land at not more than a mile 
and a half from his village. These acres he must cultivate satis- 
factorily. 
The authority of the TDA originally covered the million and 
half acres commandable by canal for irrigation, but in 1953 a 
wider scheme was examined for parts of the three and a half 
million acres not commanded by canals. In certain belts masonry 
