Though navigation here is difficult, and a strong breeze is necessary
to enable vessels to ascend the river, boat sailing is a popular
feature of European life in Assuan, a special kind of sailing-boat
being kept for visitors, who organize regattas and enjoy many a
pleasant picnic beneath the shade of the dôm palms or mimosa-trees
which grow among the rocks.

In the old days the great excursion from Assuan was by water to the
"Great Gate," as the principal rapid was called, often a difficult
matter to accomplish. To-day the great dam has replaced it as the
object of a sail.

This is the greatest engineering work of the kind ever constructed,
and spans the Nile Valley at the head of the cataract basin. It is a
mile and a quarter in length, and the river, which is raised in level
about 66 feet, pours through a great number of sluice-gates which are
opened or shut according to the season of the year and the necessities
of irrigation or navigation.

Behind, the steep valley is filled, and forms a huge lake extending
eighty miles to the south, and many pretty villages have been
submerged, while of the date-groves which surrounded them the crests
of the higher trees alone appear above water. The green island of
Philæ also is engulfed, and of the beautiful temple of Isis built upon
it only the upper portion is visible.

Below the dam activity of many kinds characterizes the Nile, as does
the sound of rushing water the Cataract basin. Above, silence reigns,
for the huge volume of stored water lies inert between its rugged