the thing loose by main strength; but
fortunately I thought better of this and fell to examining the box. I
soon saw that it was covered by a hinged lid, which was held closed by
a simple screwhook and eye.

It took but a moment to loosen this and raise the cover, when, to my
utter astonishment, I discovered an ordinary telegraph instrument
clicking away within.

"What in the world," thought I, "is this thing doing here?"

That it was a French military instrument was my first guess; but really
there didn't seem much likelihood that this was the correct
explanation, when one took into account the loneliness and remoteness
of the spot.

As I sat gazing at my remarkable find, which was ticking and clicking
away there in the silence of the desert night, trying to convey some
message which I was unable to interpret, my eyes fell upon a bit of
paper lying in the bottom of the box beside the instrument. I picked
it up and examined it. Upon it were written but two letters:

D. I.

They meant nothing to me then. I was baffled.

Once, in an interval of silence upon the part of the receiving
instrument, I moved the sending-key up and down a few times. Instantly
the receiving mechanism commenced to work frantically.

I tried to recall something of the Morse Code, with which I had played
as a little boy--but time had obliterated it from my memory. I became
almost frantic as I let my imagination run riot among the possibilities
for which this clicking instrument might stand.

Some poor devil at the unknown other end might be in dire need of
succor. The very franticness of the instrument's wild clashing
betokened something of the kind.

And there sat I, powerless to interpret, and so powerless to help!

It was then that the inspiration came to me. In a flash there leaped
to my mind the closing paragraphs of the story I had read in the club
at Algiers:

Does the answer lie somewhere upon the bosom of the broad Sahara, at
the ends of two tiny wires, hidden beneath a lost cairn?

The idea seemed preposterous. Experience and intelligence combined to
assure me that there could be no slightest grain of truth or
possibility in your wild tale--it was fiction pure and simple.

And yet where WERE the other ends of those wires?

What was this instrument--ticking away here in the great Sahara--but a
travesty upon the possible!

Would I have believed in it had I not seen it with my own eyes?

And the initials--D. I.-