the utmost was made of the sources from which
water is drawn; no pains have been spared to extract every possible drop
of water from the heart of the hills within a considerable distance, and
to convey it undiminished by evaporation to the city. This is done by
underground channels called _kanats_, which are excavated with great
ingenuity and skill, and are marvels of industry. This system prevails
all over Persia, and existence as well as the fertility of the soil
mainly depends on the water-supply thus obtained. The sandy expanse
round Yezd in the desert of South-eastern Persia has been made literally
to blossom like the rose by means of these subterranean channels, some
of which are tunnelled for a distance of thirty miles. I was there in
spring-time, and was then able to see what a wonder-worker water is in
Persia.

The pressing need of more water for Tehran has now drawn attention to
the proposals of some years ago for increasing the supply. One of these
was to divert to the south an affluent of the Upper Lar, which rises in
the Elburz range, and flows into the Caspian. It was seen that this
could be done by cutting a new channel and tunnelling from a point
sufficiently high, where the stream runs in an elevated valley between
the double ridge of the range. The work would have been similar, but
simpler, to what was completed last year in Madras, where the upper
Periyar stream was changed from a western to an eastern flow. The
execution of the Lar project would be easy, and it would not practically
affect the volume of water in the main stream, which receives many
tributaries below the proposed point of piercing the watershed. But the
Lar Valley was one of the Shah's summer retreats, and a favourite
pasture-ground for his brood mares and young stock. It is, moreover, a
popular resort of flock-owning nomads, and as the Shah's love of camp
life there led him to fear injury to the grassy plains and slopes of
his favourite highlands, the project was abandoned.

There was another scheme to construct a series of reservoirs by means of
strong barriers at the foot of the lower ravines of the Elburz range,
eight miles north of Tehran, in which to keep the winter water which
comes from the melting snow. The whole mountain-chain is covered with
snow each year from top to bottom. In April and May the snow melts, and
the precious water flows away where it is not wanted. Were this water
stored, it would be made available in the