ICE AND ITS FORMATION
"Down swept the chill wind from the mountain peak
From the snow five thousand summers old;
On open wold and hilltop bleak, it gathered all the cold--
The little brook heard it and built a roof
'Neath which he could house him, winter-proof."
When in mid-winter, pond, lake, and river are covered with a glittering
icy coat of mail, when the rushing babble of the little brook sounds
strangely muffled and restrained because of its icy fetters, then we
know that all nature is once more in the stern, iron grasp of winter,
which brings with its piercing icy breath, great discomfort, as well as
charm and exhilaration to all.
For who has not at some time in their lives revelled in the wonderful,
joyous pleasures of skating? The ice crystal-clear beneath our polished
steel, as we glided bird-like, swiftly over the polished, mirror-like
pond beneath us. What exhilaration and glow we found in the fascinating
sport. But how seldom, if ever, did we give a thought to the wonderful
formation, and the beauties of that crystal surface beneath our flying
feet, or did we dream that every bit of that ice was cemented and joined
together in exquisite mosaic-like patterns, formed by countless millions
of tiny ice flowers, far too delicate and small to be seen by the naked
eye. This wonderful process of ice formation goes on, as Lowell so
charmingly writes:
"All night by the white stars' frosty gleams
He groined his arches and matched his beams;
Slender and clear were his crystal spars
As the lashes of light that trim the stars;
Sometimes his tinkling waters slipt
Down through a frost-leaved forest-crypt."
[Illustration: 110. Feathery type]
[Illustration: 111. Clear prism-like branches]
[Illustration: 112. Solid type. Probably travelled a long distance]
[Illustration: 113. Low altitude crystal. Usually feathery and light in
construction.]
The conversion of liquid water through freezing into a solid crystalline
state is certainly a most interesting process, as well as a mysterious
one. There are many more difficulties to be encountered by crystal
photographers in the study of ice formation, and its minute detail, than
in that of either the snow or frost. Still many instructive and very
interesting experiments have been made and facts obtained relating to
the formation of the ice, and it has recently been possible to secure a
valuable set of photographs which are wonderfully interesting, inasmuch
as they serve to show the singular formation and development of ice
crystal structure from start to finish.
Ice and water are so optically alike, that the formation of these ice
crystals cannot be clearly detected without the aid of a microscope.
These ethereal ice flowers are extremely frail and thin, less than one
one-hundredth of an inch in thickness; and they vary from just a mere
microscopic speck, to one-third of an inch or so in tabular diameter.
Generally every freezing body of water contains these beautiful ice
crystals; myriads of tiny transparent ice flowers which assume distinct
types and groups, more or less symmetrical. In order to watch the growth
and development of these ice crystals which build up in such quantities
on the surface of pond, river and brook, and which go, as a whole, to
form solid ice, certain artificial conditions of light are necessary.
These may be simply furnished by using a small mirror placed in a
horizontal position beneath the surface of the water which is in process
of freezing. Or, if one wishes to make an interesting study of the
strange phenomena within doors, it may be quite possible to do so by
simply placing water in a pail, and in the bottom of the pail, beneath
the water, a mirror in a horizontal position. Of course the water should
be kept in a cold room where it will freeze, or beneath an open window.
The mirror affords the necessary white background, and in this manner
ice in process of freezing may be plainly viewed from its first germ
growth to the finished ice crystal.
[Illustration: 114. Having notably elaborate centre]
[Illustration: 115. Very elaborate design]
[Illustration: 116. The arrow crystal. Six well defined arrows in the
design]
[Illustration: 117. Low altitude type]
The process by which each water molecule, obedient to the great laws
which govern nature, draws together in countless numbers to form and
build themselves into countless flower-like ice crystals, which go to
form solid ice is a magical, fascinating process, well worth watching.
The types of ice crystals differ, however, upon still surfaces, to those
which form upon running or disturbed water. Still, such a similarity
exists in all ice crystal formation, and their habits of growth, that
one may get a very clear idea of the process of their development by
observing it in the simple manner above described.
Their different stages of growth is very clearly divided into five or
six types of crystalline formation, and they pass from beginning to end,
through the various stages of development as the nuclear, or
smooth-edged crystal, the scalloped, the ray-like and the branching
stages of growth; after which they lose their individuality by becoming
solidified and merged into the solid ice form.
When the ice flowers or crystals first begin to appear, it is usually
upon the surface of the water, and close to the sides of the pail.
Frequently they push out in long, delicate, needle- or lance-like forms
while upon the plain edges of these sharp lances, scallops and delicate
serrations quickly follow. But the individual or flower type of crystals
which grow and scatter themselves over the surface of the water, do not
attach themselves to any object, but grow in a detached fashion, and are
really the most interesting crystal for observation and study. These
detached crystals following out the laws which govern also the frost and
snow crystals from their first stage of development, form a simple,
smooth-edged disc of very thin transparent ice, gradually merging into
the same, hexagonal, flower-like pattern, which governs the frost and
snow crystals, although during the first stages of their development
they show no tendency to follow hexagonal outlines. The photographed
illustrations showing this type of ice crystal, from its start to finish
were most of them taken from indoor observation.
[Illustration: 118. High altitude crystal with germs attached]
[Illustration: 119. A daintily etched centre design]
Beginning with photograph No. 128, we have the germ or birth, showing
the first stage which the ice crystal assumes in its formation. It is
always seen as a round disc of very clear, thin ice.
No. 129 illustrates the second stage of growth in which the tiny
serrations or scallops are just beginning to shoot out and form about
the germ or disc. Frequently they remain in this stage of development
for some time without further change, but when it is zero weather they
quickly increase in growth, and soon begin to show clearly defined
scallops as shown in photograph No. 130.
In No. 131, the ice crystal has at last begun to assume definite form,
and its hexagonal shape is more clearly defined; while in No. 132, we
have the completed flower-like outline, and in Nos. 133 and 134 the
finished ice flower with its air inclusions of light and shade
perfected. This shows the entire process of growth of the commonest type
of these ice crystals, after which process they lose their identity and
merge into the solid ice film.
However, ice film growth is not wholly supported in this manner, for
branches often form upon the under side of the ice film, and grow
downward into the water, as shown in photograph No. 135, which is a
section of ice with fern-like crystal-growth growing down into the
water, thus aiding in growth and solidification. Each type of crystal,
and there are five, represents some different characteristic growth--the
long, narrow, needle type, the simple stars of six points, and the
spherical or discoidal forms; also those resembling coral-like
formations.
[Illustration: 120. Branchy trigonal crystal]
[Illustration: 121. An uncommon type]
Photograph No. 136 shows how individual ice flowers hamper each other in
growth; that the points reaching out into clear water grow and draw to
themselves with greater freedom the water molecules, while the points
intruded upon or crowded out by other crystals or flowers, cease to
grow, and do not interfere with the growth of others.
Nos. 137 and 138 are still other forms of ice-growth, the needle-like,
lance-like form which we may frequently observe pushing out from the
banks of a small pond or brook. These needle-like forms of ice
eventually acquire branches about their entire radius, which grow and
merge, with other ice flowers of different types, into solid ice upon
the surface of the water.
No. 139 shows this type of ice-crystal completed. These ice-crystals
form and rise like magic in early winter, especially upon and around the
new ice upon the edges of small brooks, and streams.
"Sometimes the roof no fretwork knew
But silvery mosses that downward grew;
Sometimes it was carved in sharp relief
With quaint arabesques of ice-fern leaf."
Another very interesting example of ice-growth and formation which we
occasionally discover upon the window-panes, and which should not be
confounded with the frost work etchings, as it is in reality a thin
transparent ice film, which frequently assumes exquisite formations and
patterns. In No. 141 _a_ the coral-like branch is a beautiful example of
this window-pane ice, while upon the same pane of glass in precisely the
same temperature we find another type, as 141 _b_ resembling somewhat
the transparent wing of an insect. There are but two distinct types of
the ice film etchings, and they are classified as the feather form and
the arborescent types. It is presumed that the forming of types is
largely governed by the varying thickness of the glass upon which the
ice film is deposited, and to the presence or absence of minute frozen
particles of ice beneath the film. The feather form seems to develop
upon cooler positions of the glass, and where the water film is
thinnest.
[Illustration: 122. One of the most elaborate crystals shown. Notable
for its very dark centre and the curious detail of its border]
[Illustration: 123. A rare design because of its open petal-like
formation. Usually such crystals are solid]
[Illustration: 124. Very frigid altitude crystal having remarkably
etched centre]
[Illustration: 125. A snow crystal covered with granular deposit of
frost]
Nos. 142, 143, and 144 are all rare examples of window ice. No. 16 shows
to perfection a greatly magnified section of the coral-like tracings in
detail. This window-pane ice, unlike the frost etchings, is always
transparent or opaque water ice.
The ice pictures form in rather an exclusive fashion, and two types
never intrude upon each other's territory, although we often find both
types upon one pane of glass, as shown in the photographed illustration
Nos. 140 _a_ and 140 _b_.
The ice films always begin to develop upon the colder portions of the
glass first. Feathery plume-like designs form first upon shaded
portions, and slowly follow the fading sunlight as it passes from one
pane to another, until the entire window is often covered with these
transparent ice pictures. During zero weather the feathery types thicken
to an astonishing degree, more so than the opposite type, or arborescent
ice film.
Another type of ice formation, and an interesting one, which in the
photograph resembles somewhat a vegetable root or growth, is a form of
ice which develops and grows upon and under peaty soil. These singular
little ice columns rise as by magic, and form a miniature forest of tiny
ice columns; frequently raising upon their tops the soil, stones, etc.,
to a height of many inches.
[Illustration: 126. Local storm type]
[Illustration: 127. Cold high altitude]
Nos. 145, 146 and 147, show photographed examples of this type of
columnar ice, No. 147 being a largely magnified section of one of these
tiny columns in detail. Icicles are another interesting phenomenon
belonging to ice study. They are evidently produced by the thawing of
snow, and we frequently discover "freak" icicles hanging pendent from
the house eaves during a thaw. They are, in a way, one of the many
mysteries pertaining, and to be classed as ice crystallisations, and are
closely related to the wonderful stalactite formations found in deep
caves.
Beautiful beyond powers of description are the magical, fairy-like
scenes which follow the passing of a great ice-storm. If you are out of
doors just after such a storm, when the first rays of the sun begin to
shine forth, lighting and touching every ice-sheathed twig with gold,
and before the ice has begun to melt and fall from the trees, you can
well imagine that you are catching a fleeting glimpse of fairyland!
Trees that before the storm waved their leaf-stripped branches, bare and
unlovely, in wailing symphony, tuned by the bleak wintry blast, have
suddenly been clothed anew and made beautiful for a brief time, by their
silvery coating of ice. Each tiny twig glitters and scintillates and
crackles beneath the pale wintry sunshine; beautiful beyond words to
picture.
These ice-storms occur more frequently in January, and are usually
followed by a warm wave. They are seen in all their beauty in the New
England States. Frequently after such an ice-storm there is a noticeable
swelling and expansion of twigs and buds; the first suggestion of
verdure and an early spring.
It is intended in this article but to touch upon the simple structural
formation of the ice. There are still many important facts to discover,
many interesting problems to solve. It would be interesting to know why
the ice crystals which originate and have their being in the same body
of water, and under precisely the same conditions of temperature vary so
greatly in their structural formation.
[Illustration: 128. Germ or birth of ice crystal]
[Illustration: 129. Discoidal ice crystal. Second stage in which crimps
begin to appear around the edge of disc]
[Illustration: 130. Third stage of development. Scallops well defined]
Ice crystallisation in all its branches is a fascinating and wonderfully
instructive study. It is still in its infancy, there is much as yet
undiscovered material for experiment awaiting both the student and the
camera specialist.
"Sometimes it was simply smooth and clear
For the gladness of Heaven to shine through, and here
He had caught the nodding bulrush tops
And hung them thickly with diamond drops,
That crystallised the beams of moon and sun,
And made a star of every one:
No mortal builder's rare device
Could match this winter-palace of ice."
--Lowell.
[Illustration: 131. Fourth stage, flower-like shape beginning to show]
[Illustration: 132. Ice flower completed]
[Illustration: 133. Flower-like shape fully formed]
[Illustration: 134. Ice flower beginning to show shadings]
THE BENEFICENT RAIN
[Illustration: 135. Ice crystals growing downwards into the brook]
[Illustration: 136. Group of ice crystals. Observe how in growing they
avoid other]
[Illustration: 137. First stage. Lance-like form seen pushing out from
banks of brooks]