brain. Anyway, the man behind you does actually walk on your ----
heels every second step.

In the desert, also, did we dig trenches. No, not the same thing as
digging trenches anywhere! For it is really nearly as easy to dig
trenches in the ocean. For every spadeful you throw out two fall in,
and if, by the use of much cunning, you _do_ manage to get a hole dug,
then you must not leave it for a single instant, for it is only waiting
until your back is turned to disappear. There is one thing--those
trenches were good cover, for we would no sooner occupy them than we
would be covered up entirely. I would defy an aeroplane with the best
"made in Germany" spectacles to discover whether we were men or mummies.

But we had one very exciting trench-digging expedition. We dug, if you
please, into an old city, and broke into tombs umpteen thousand years
old. There were scarabs and ancient jewels there that the Field Museum
would give their eye-teeth for. We were ordered to deliver our finds
to the authorities, but I am afraid many of the boys had "sticky"
fingers. It was all jolly interesting, but there is a fly in every box
of ointment, and the supposed age of these relics brought home to us
the fact that this soil had been lived on for thousands of years by
people much like our present neighbors, without any sanitary ideas; and
one of our fellows with a scientific mind pictured to us every grain of
sand as being a globe inhabited by germs. This was comforting, for we
each of us swallowed a few billion of these "universes" every day!
They got in our eyes, in our ears, in our nose and mouth, but if they
got into a cut by any chance, then we were subjects for the doctor.
"Oh Egypt, thou land of teeming life, how healthy wouldst thou be if
you weren't so overcrowded!"