Picture - Cosmic Polymath

PREVALENCE OF SPIRAL ARRANGEMENTS 1
Fifi. 3.—Study of a spiral sand-storm by the Author. Drawn'by C. Berjeau.
at the same time. In water-spouts on land the upper cone consists of a mass of clouds, and the lower cone of sand,
dust, and other bodies found on land. Deluges of rain accompany their disruption."
According to another authority (" Century Dictionary," edited by Dr. W. Dwight Whitney), " The water-spout
is a whirlwind over a body of water, which produces the appearance of a solid column of water, extending from the
surface to the clouds. In reality, however, the phenomenon that is seen is the cloud brought down to the earth's
surface by the rapid gyratory motion of a vertical whirl, and it consists simply of fine mist surrounding a central
axis of rarefaction. At first the cloud has the form of a tapering funnel ; then, descending to near the water's surface,
it draws up the water for a distance into its vortex, and imparts to it its whirling motion. The spout is then com-
plete, and appears as an immense column connecting sea and cloud, light in colour near the centre, but dark along
its sides. Like other whirlwinds, the water-spout has a progressive as well as a rotatory motion, its axis sometimes
being inclined forward in the direction of advance. ... It is common for a number of water-spouts to be seen simul-
taneously or successively " (Plate vi.. Figs. 1 and 2).
Before leaving the subject of fluid spiral formations it may be interesting to direct attention to the spiral made
by the escape of ether in water placed in a red-hot silver basin (Fig. 4), and to the vortex ring made by smoke in its
first stage (Fig. 5), as delineated by Mr. F. Hovenden.^
The vortices formed by nebulaj are, in some respects, the most wonderful of all. So far as I can make out they
originate in three ways :
(a) Bv a nebular mass or nucleus assuming a rotatory or spiral motion in space and drawing towards it, in
well-marked spiral lines, smaller nebular masses ; (6) by a converse process, whereby the smaller nebular masses
assume spiral movements and coalesce to form a spherical or spiral nebular nucleus ; and
(c) by a resolving or
disintegrating process, whereby the nucleus or central core throws off its substance in spiral streams, usually
two in number—these forming right or left-handed spirals. There is what is practically a spiral infolding and
evolving process at work ; a spiral overlapping in one direction, and a spiral unlapping in another and opposite
direction.
There are good grounds for believing that spiral nebulous matter is not in every instance formative matter,
that is, spiral matter aggregating and building up stellar and other bodies. On the contrary, it may very well be
the spiral detritus of stars and other heavenly bodies breaking up and disintegrating. If this threefold view
1 " What is Heat and what is Electricity ? " by F. Hovenden, F.L.S., F.G.S., F R.M.S. London, 1900.