The aegis & intelligencer. [volume] (Bel Air, Md.) 1864-1923, 1881-06-17
miscellaneous.


How is ground ice formed in the rapids of our
rivers, and on the beds Of our rapld-tlowing
streams! This is one of the long -moOted Ques-
tons among scientific men, for the solution of
which the writer has been looking in vain to the
professors of our institutions of learning, and eS-
pecially to the scientific associations of our coun
try But when such able authority as Dr.
Brandes Encyclopedia says, lit is formed under
peculiar circumstances" and there leaves the
matter rest-a work so elaborate in definitions
and explanations on other questions of general
interest, am led to believe that he does not know
or that he considers it lacks sufficient interest to
justify investigation. Abstrusc, however, as the
question Is, 1t was ably and thoroughly treated by
SCIENTISTS III the latter part of the last century.
The theory of MIR. Knight falls short of account
ing for the facts which he himself observed, for
by supposlng the spicua to have been formed at
the surface and afterwards precptuted by 1.-THE
trembling motion of the water to the bottom" ii
doesnot contain any explanation of that congo
lation which must go on ut the bottom itself be-
fore the spicula can adhere to the objects on the
bed OF the river, as rocks, Sticks grass and con-
gerics in tho cddies.
Men of science not having attended to these
phenomena, have considered them, when acct
IDENTITY met with, as extraordinary. 1t has no
doubt happened when they were in quest of some
thing else that they found ut the bottom of river
seemingly sandy mass, agglutinatcd in a man
ner which they did not comprehend, till they
found the accretion was Ice. At other times they
have been struck with great surprise on finding
gravel, mud or earth mixed with the ice floating
on the surface, but inwardy fail to elucidate the
precipitation OF the frozen crystals from the sur
face to the bed of the river which is of itself the
object as well as the solution of the question.
1t strikes me as rather remarkable that this
subject should have been left lay SO long unfiTl-
ished; at least L am not aware of any modern
writer having undertaken to explain it, until /
casually observed the report of Il paper read be-
fore the Davenport, Iowa, Academy of Natural
Sciences, by ID. H. j. Farquharson, whose theory
is this, that rapidly flowing water will get so
mixed that the temperature becomes uniform,
and when at the freezing point an arrest of no
ton will favor congelaton, that there is need
ed but the slack water afforded by the eddy of a
a a. IN in
stantly into spongy mass" This is another in
stance of the failure of labored effort of the
author to throw any additional light on the sub
ject, as in the case of Mr. Knight, on the river
Thames, in England neither OF whom seem to
comprehend the question, except, with respect to
the equalization of the temperature Floating OBJ
jects or objects lighter than water sinking to the
bed of the river without additional weight seems
paradoxical, but which is nevertheless true in
fact. Here on the Susquehanna, river four
hundred miles long, whose remotest tributaries
have an elevation Of upwards of eight hundred
feet above tde-water, we have great facilities to
observe and investigate these phenomena, but no
better than is afforded others pursuing the same
research on the river Avon, in England, and on
the Elb in Germany.
If this instantaneous process of the congelation
of spongy masses of ice were true, who would for
moment suppose that the fine alluvial bottom
lands, forming the shores of the Susquehanna,
would be tenable as farm lands and secure home
steads, during the periods of the low temperature
of our winters here The pent up waters of a
system OF natural causes so extensive in its rami-
ficatiOns, with its series after series, of spOngy
ice DAMS formed every cold night and possibly
break away every morning, flooding the shores,
damaging and destroying more or less property
as often as the occurrence might take place.
ask no stronger evidence OF the ialacy of the Doc
tors theory than the non-occurrence of such cf-
fectS on the SuSquehanna.
THE SOLUTION.
Ice is concealed water and it forms on the sur
face of the stream, however rapid or sluggish the
flow may be, at the temperature of 2o Fahren-
heit, never on the bottom but it gets there new
ertheess, and us others more able than am have
In az f,l hnu
that it has fallen to my lot to settle the question:
II ii can he settled at all. We say water flows
and believe ii does and no one denies it we also
say IL rolls; and | feel sure no sane will I'M
dertake to dispute it. Now, since it docs both,
except when at rest we establish the fact that its
movement over an inclined bed assumes the
double form of flow and roll Objects on the sur
face are carried along faster than objects mid
way of its depth. This fact is patent TO all close
observers.
Objects thus put in motion under the surface
are AS often on the surface, but of less duration
This has reference only to objects which would
sink IN water at rest, and float when set in motion
Ice excepted water contains a large percentage
OF air, in the form of minute bubbles which
tnrned up and expose by the rotary motion of
the water, are congealed and quickly carried I'M
der and down to the bottom of the river. 1t is by
this process that the temperature is cqualized top
and bottom, also that the objects ON the bed of
the river, the crystals thus formed, must of me-
cessity come In contact with objects of the same
| temperature to which they cling, as gold dust
clogs 10 the woolly fleece of the blanket forming
| the nucleus of bodies, large and small in every
direction over the bed of the river, as crcum-
stances more or less favor the formation of such
bodies. These bodies are developed with degree
of rapidity, equalled only and in the same man
ner, as snow flakes fall from the sky and when
| they reach certain dimensions and can no longer
| resist the force Of the stream, they yield their
| grasp, rise to the surface, and pass on with the
current, clinging here and there to the shores,
rocks and islands, until the surface is closed and
solidited by sheet ice. In the mean time how
| ever large proportion of the CONCEALED CRYSTALS
run together on the surface, forming spicula, too
n 40 min IN al.N
are acquiring circular formations from two to
| Ave feet in diameter.
When the river becomes "closed," the forma-
| ton of ground ice ceases, except in the rapids
and In its descent 1t passes under the standing ice
10 which 1t adheres, and dsposes itself with won
derful uniformity. After the ice acquires the
depth of six inches 1t ceases to increase in thick
ness, unless the temperature goes several degrees
below 32, and it has been observed and frequently
| remarked, that the ice formed over rapid cur
rent, is, to great degree freer from air gobules
than ice formed over sluggish flow of the stream
No perceptible difference however, in thickness
has been noted. s,
lYhuT1SCtWe.