this haze, indicated rather than definitely seen,
was a constant nicker of lightning. It was the ordinary heat-lightning
of the tropics, which is noiseless, but it somehow seemed to send out
little throbs into the baking air, till, at times, to be alive was for a
white man almost intolerable.

[Illustration: THE LITTLE ARMY COULD ONLY MARCH IN SINGLE FILE.]

Under this discomfort, a predatory column was marching on from one
captured village to another, whose possible store of ivory had so far
not been gleaned. The road was the ordinary African bush-path, intensely
winding and only foot-sole wide; the little army, with Kettle at its
head, could only march in single file, and Clay, who brought up the
straggling rear, sweated and panted quite half a mile behind his leader.

Every one knew the tornado was approaching, and both the worn and
haggard white men and the sweating, malodorous blacks hoped for it with
equal intensity. For be it known that the tropical tornado passes
through the stale baked air at intervals, like some gigantic sieve,
dredging out its surplus heat and impurities. The which is a necessity
of Nature; else even the black man could not endure in those regions.

And in due time, though it lingered most cruelly in its approach, the
tornado burst upon them, coming with an insane volley of rain and wind
and sound, that filled the forests with crashings, and sent the parched
earth flying in vicious mud-spirts. In a Northern country such a furious
outburst would have filled people with alarm; but here, in the tropic
wilderness, custom had robbed the tornado of its dignity; and no one was
awed. Indeed the blacks fairly basked in its violence, turning their
glistening bodies luxuriously under the great ropes of rain.

The march stopped at the first outbreak of the squall. Kettle bolted to
a rock ahead of him, and squatted down in a dry lee, sucking up great
draughts of the new cool air. There are times when a drop of five
degrees of temperature can bring earthly bliss of a quality almost
unimaginable. And there he stayed, philosophically waiting till the
tornado should choose to blow itself out.

The wind had started with a roar and a sudden squall, reaching the full
climax of its strength in a matter of thirty seconds, and then with
equal hurry it ended, leaving the country it had scoured full of a
fresh, cool, glistening calm. Kettle rose to his feet, shook his clothes
into shape, and gave the order to st