228 
TIIK BASIX OF EASTERN PERSIA AND SISTAN. 
water, the evaporation of wliich cools the air thai whistles throii<^h and Riuk-rs the 
interior comfortable. When the wind dies down for a day or two, as happens 
occasionally, the houses become insufierably hot and myriads of flies and mosquitoes 
at once swarm everywhere. 
The strent^th and uniform direction of the wind allow windmills to be constructed 
with simplicity and ease. The wheel is shaped like an old-fashioned water-wheel, 6 
or 8 feet long, and is set vertically on the roof of the mill, directly over the stone which 
Fig. 149. — Windmills al Tabas. 
it is to turn (fig. 149). About the wheel is built a high mud wall, which is left open on 
the south side and on the western half of the north side (fig. 150). The wind enters 
I through the slit at the north, turns the wheel, and finds an exit to 
*'"'""^ the south. Often ten or twelve mills are set in a row, east and w^est, 
and at Neh, northwest of Sistan, I saw fifty. One unfortunate effect 
of the wind is that in Sistan no fniit can be raised upon trees, and in 
certain places even melons can not thrive. The wild watermelon, 
which matures its beautiful but intensely acrid little green and yellow 
fruits in the dr}' "nullah" beds, has learned to withstand the wind. 
Normally, the vine spreads in all directions, but under the influence 
of the wind the branches are bent to the south, and lie in a long bunch so exactly 
oriented that the plants might almost ser\'e as a compass. Three that I measured 
were directed S. 3° E., S. 17° E., and S. 11° E. 
V 
Fia. 150 Hori- 
zoQtal section of a 
Persian wiDdmill. 
