ir girth, for their outline was so hazy that it
seemed to fade away into the air around them. These air-snakes were of
a very light grey or smoke colour, with some darker lines within, which
gave the impression of a definite organism. One of them whisked past
my very face, and I was conscious of a cold, clammy contact, but their
composition was so unsubstantial that I could not connect them with any
thought of physical danger, any more than the beautiful bell-like
creatures which had preceded them. There was no more solidity in their
frames than in the floating spume from a broken wave.

"But a more terrible experience was in store for me. Floating
downwards from a great height there came a purplish patch of vapour,
small as I saw it first, but rapidly enlarging as it approached me,
until it appeared to be hundreds of square feet in size. Though
fashioned of some transparent, jelly-like substance, it was none the
less of much more definite outline and solid consistence than anything
which I had seen before. There were more traces, too, of a physical
organization, especially two vast, shadowy, circular plates upon either
side, which may have been eyes, and a perfectly solid white projection
between them which was as curved and cruel as the beak of a vulture.

"The whole aspect of this monster was formidable and threatening, and
it kept changing its colour from a very light mauve to a dark, angry
purple so thick that it cast a shadow as it drifted between my
monoplane and the sun. On the upper curve of its huge body there were
three great projections which I can only describe as enormous bubbles,
and I was convinced as I looked at them that they were charged with
some extremely light gas which served to buoy up the misshapen and
semi-solid mass in the rarefied air. The creature moved swiftly along,
keeping pace easily with the monoplane, and for twenty miles or more it
formed my horrible escort, hovering over me like a bird of prey which
is waiting to pounce. Its method of progression--done so swiftly that
it was not easy to follow--was to throw out a long, glutinous streamer
in front of it, which in turn seemed to draw forward the rest of the
writhing body. So elastic and gelatinous was it that never for two
successive minutes was it the same shape, and yet each change made it
more threatening and loathsome than the last.

"I knew that it meant mischief. Every purple flush of its hideous body
told me so. Th