rt is the geological formation of the soil and the only amusement is
to examine the different beautifully coloured stones that can be picked
up, such as handsome agates, bits of malachite, crystals, beautiful
marbles, and flints. These are all the more interesting when one thinks
that most of them may have travelled hundreds, some, thousands of miles
to get there, either brought by the water when the country was submerged
or shifted on and on by the wind. They all bear marks of travel, and even
the hardest are polished smooth, the original natural angles of crystals
being in many cases actually worn down and quite rounded. Sand-polished
pebbles of red jasper, jasper-conglomerates, chalcedony, quartz and
agatescent quartz, pink and brown corroded limestone, and calcite were
the most frequently met with.

A desert is, in England, always associated with glorious sunsets. Why
this should be so is rather difficult to be understood by anybody
reasoning in the right way, because the magnificent tints of a sunset are
caused by moisture in the air and not by abnormal dryness. All the time
that I was in the desert itself I never saw a sunset that really had half
the picturesqueness of one of our most modest sunsets in Europe. The sun
disappeared very fast, leaving a slightly yellow glow above the horizon,
which soon became greenish by blending with the blue sky and then black
with night. The twilight was extremely short.

We seldom saw clouds at all in the desert and when we did they were
scrubby, little, patchy, angular lumps at enormous heights above the
earth's surface. They were generally white or light grey. Occasionally
they were of the fish-bone pattern, in long successive ridges, resembling
the waves formed on the sand surface when shifted by wind. Soon after the
sun had disappeared behind the horizon, these clouds generally changed
their colour from white into black and made long lines stretching for
great distances across the sky, but adding no beauty to it.

Naturally, the play of shifting lights and shadows upon the desert when
the sun shone above the clouds was quite weird, especially when the last
formation of clouds referred to cast long bluish shadows slowly moving
upon the brilliantly-lighted, whitish tint of the ground. Lower upon the
horizon line a curtain of a dirty brownish tint was generally to be seen,
due to particles of sand in the air, otherwise in almost all cases that
came under my observation the clo