Quotation from: The Land That Time Forgot

Written by: Edgar Rice Burroughs

Then I found a tiny handkerchief close to the outer wall.
Lys had been stolen! It was all too plain. Some hideous member
of the ape-man tribe had entered the fort and carried her off.
While I stood stunned and horrified at the frightful evidence
before me, there came from the direction of the great lake an
increasing sound that rose to the volume of a shriek. We all
looked up as the noise approached apparently just above us, and
a moment later there followed a terrific explosion which hurled
us to the ground. When we clambered to our feet, we saw a large
section of the west wall torn and shattered. It was Olson who
first recovered from his daze sufficiently to guess the
explanation of the phenomenon.