St. Charles City Republican intelligencer. [volume] (St. Charles City [Charles City], Iowa) 1857-1861, 1860-09-06
stiisnti6t.
AMERICAN ASSOCIATION
FOR THE ADVANCEMENT Ef SCIENCE

r"I' ltt' ADV ANtEMENT EF SCIENCE.
This Association have been holding
their annua! session at Newport, Il. l.
The attendance was large, and the
proceedings were highly interesting
Professor Loomis presented u very
interesting paper on natural ice
houses and frozen wells. He stated
that considerable number Of these
existed in different parts of the world
and usually consisted in caves, situ-
atcd at greater or less depth, in
which the circulation of air was very
limited. Under these circumstances,
the natural tendency of the cold air
was to sink to the lowest position,
and when once SO established, the
want of circulation prevented its as
cent. In this manner it happened
that at depth Of a few hundred feet, /.
the air 50 far from being warmer than
the external air in cold weather, as
might readily be expected from the .
natural increase Of the temperature of
the earth, was absolutely SO much
colder, as not only to freeze water, .
cut to preserve ice late in the season, |
and in some places, perpctually. In
cave Of this description, used as an
iron quarry, in the northern part of
New York, upon Lake Champlain, at
a depth of two hundred feet, the ten
pcraturc in winter was 50 much re-
duccd us frequently to cause the work
men to suspend their operations. He
presented two tables, one giving the
locations Of the natural icc-hOuscs
found in Europe, the other those III the
United States. The latter number
about twelve. One Of these was at
Brandon, Vermont, and another III
Iowa, in latitude i3. The same phc- /.
nomcuon, was frequently observed in
deep wells, and was due to the same .
cause sually, the water i'll wells .
was supplied by running underground .
streams. When this was the case,
the change in the water was such /
that when one portion became chilled,
another took its place, and thus pre-
vented it from freezing But there
were wells in which the water was
nearly stationary, and i'll these cases
the formation OF ice was a natural Oc-
currencc. In the geological depart
mcnt, a paper on tue synchromsm OF
the coal beds in Rhode Island and the
Western States, 10y c. II. Hitchcock,
gave rise to an animated discussion,
in which Professors Rogers, New bcr-
ry and Agassiz took part. Both Prof. |
Rogers and Agassiz agreed that it .
was Il mistake to make too hasty gen .
cralizatiOns of immense districts, and .
thought that one of the most deceptive /
things in connection with the coal /
strata was the continuity of the same .
This was true in regard to special To-
calitics where the observer was frc-
qucntly unable to trace a seam con-
tinuously, and especially SO where we
include an lmmcuSc tract extending
over and area as great as that includ-
cd in the coal field in the United
States. Professor Agassiz thought
that sufficient attention had not been
given to the different vegetation of
different latitudcs i'll accounting for
the space of time occupied in the coal
formation. He called attention to the
bogs OF Massachusetts,, and the
swamps Of Florida covered with pine
trees, as evidences of the differences
/ in vegetation even i'll Il limited extent
of country. Both Of these were in a
condition to be converted into coal
| beds, and without attention to this
! fact some future observer might as
sign different craS to their formation.
Prof. Whitney had arrived at some
conclusions i'll regard to the lead de-
posits, which differed materially from
those hitherto expressed by former
Biologists. In order to understand
his views, it would be necessary to
enter into a brief but general dcscrip-
ton of the geological characteristics
of the lcad-bcaring region. The lead
deposits were almost invariably found
in the Northwest in the siIverian
strata, and not like gold, silver and
copper, in mctamorphoscd rock. The
whole surface included in this region
was about the size of that of the State
of Connecticut In this limited space
was procured about One-eighth of all
the lead used in the world. Mining
was always attended with some haZ-
ard, and it was probably owing to the
uncertainties of its results that its
fascination was chiefly due. In the
New England States, with the cXcep-
ton Of iron ore beds, he knew of no
department of mining that had result
cd i'll profit to the projectors. Recent
improvements had greatly reduced
the risks, more especially that cor
rect knowledge induced by accurate
geological surveys.
The lead in the Northwest was
usually found in sheets, penetrating
the rocky formation from twenty to
forty feet-seldom more than one hun
dred and forty, and varying in thick
ness from that Of knife blade to
three inches. Three sheets opened
into disintcgratcd masses, which
usually furnished the lead Of COM
mcrcc. The strata i'll which these
sheets were found were in a great
state of reposc, and furnished none of
the evidences found in other districts
of igncous origin. On the contrary,
there were many facts which proved
the formation to be injected from
above either in an acriIorm or fluid
state. The only one to which he
would call attention was, that in
large cave evidences Of crystalization
similar to that observed in lime de-
posits from the upper part, were
abundantly manifest This fact was
an important one, and one in which