ries of photographs show this well.

[Illustration: FIG. 8.]

[Illustration: FIG. 9.]

There is a far more perfect illustration which we have only to go into
the garden to find. There we may see in abundance what is now upon the
screen--the webs of those beautiful geometrical spiders. The radial
threads are smooth like the one you saw a few minutes ago, but the
threads that go round and round are beaded. The spider draws these
webs slowly, and at the same time pours upon them a liquid, and still
further to obtain the effect of launching a liquid cylinder in space
he, or rather she, pulls it out like the string of a bow, and lets it
go with a jerk. The liquid cylinder cannot exist, and the result is
what you now see upon the screen (Fig. 8). A more perfect illustration
of the regular breaking up of a liquid cylinder it would be impossible
to find. The beads are, as Plateau showed they ought to be,
alternately large and small, and their regularity is marvelous.
Sometimes two still smaller beads are developed, as may be seen in the
second photograph, thus completely agreeing with the results of
Plateau's investigations.

I have heard it maintained that the spider goes round her web and
places these beads there afterward. But since a web with about 360,000
beads is completed in an hour--that is at the rate of about 100 a
second--this does not seem likely. That what I have said is true, is
made more probable by the photograph of a beaded web that I have made
myself by simply stroking a quartz fiber with a straw wetted with
castor oil (Fig. 9); it is rather larger than a spider line; but I
have made beaded threads, using a fine fiber, quite indistinguishable
from a real spider web, and they have the further similarity that they
are just as good for catching flies.

Now, going back to the melted quartz, it is evident that if it ever
became perfectly liquid, it could not exist as a fiber for an instant.
It is the extreme viscosity of quartz, at the heat even of an electric
arc, that makes these fibers possible. The only difference between
quartz in the oxyhydrogen jet and quartz in the arc is that in the
first you make threads and in the second are blown bubbles. I have in
my hand some microscopic bubbles of quartz showing all the perfection
of form and color that we are familiar with in the soap bubble.

An invaluable property of quartz is its power of insulating perfectly,
even in an atmosphere saturated with water. Th