New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1880-11-18

observations on ice and icebergs III the polar regions
were listened 20 with interest. The formation OF
iceberes from the terminal fronts of glaciers Lieu
tenant Schwatka said, has long been disputed
point among savants. some contending that they tie
rive heir origin from the corroding action OF the
water undermining their projecting faces until the
weight of the superintendent mass acting on a
lever overcame the cohesive power of the glacier
aloug some line of least resistance, when the hcrg
fell into the sea and was waited away by the tide
winds and currents. Others cOuld only account for
such huge mountains OF ice ny snpp0sing thai the
glacier slowly crawling into the and Dlungiug
beuelth denser fund, had bouyant effort or ten
deHcy to rise which at last became 20 great that 10
Ovrrcame the line OF least resistance the shore
and the berg into the TO be at the further
mercy of It's uncertain elements. Both theories
have proved TO he correct. Tho former generally
occurs where currents heated in more temperate
chimes pour their tepd waters nOrthward ana ex-
pend their thermal forces in contending with the
vast packs. foes and glaciers of ice that OBJ
struct their polar march, ard whose fast
corrOding action has The slow glacier
only comparatively short time IN its embraces be-
the chilled waters from tho Pole have bat little
effect upon the glacial front and slow as il is, II
has time to crawl into the sea to give forth It's
mighty masses. Sometimes both kinds of forces
are acting simultaneously upon the same glacieT,
and while huge icy mountains at intervals o.
centuries rising from their use. watery bed, othoT
aud smaller ones are more freq leutlY dropping from
It's scaward lace, Tor those formed 10y dropping are
far smaller than those which rise into the A.
though about StNcu-elgnLlS OF an iceberg ~ sub
merged, Ii must not be Inferred that when lis
height has been determined, seven times that
height IS It's depth below the sea level. If OF
tabular shape, this proportion becomes nearly
but If OF a pYramdai or cOnOidal cross sec
ton. which Is Tar OIteneT the case. the iineal pIO-
portions OF height to depth approach each other
more closely while the volumes necessary, to
hydrostatc equilibrium remain inYarabe.
Their great height as compared with
their breadth, would show that these
iineal proportions did not obtain beneath the sea
lev fNp ma n uotb n n "A
state of stable equilibrium, and would topic over.
fact which sometimes happens when the condi-
tiOns of equilibrium are disturbed by the unsym-
mct.ical decrease of It's different faces
The he ght OF bergs, estimated or measured by
various Arctic Voyagers, yarie greatly During the
warm months OF summer when they most FREE
quently encountered by navigatOrs, they are often
surrounded by hazy mist; due 10 the condensation
OF the surrounding moisture by their chilly faces,
and tho effect is 10 make them appear much higher
than they really are, winch renders estimates OF
their height particularly unreliable.
AS about seven-eiehths OF an iceberg is under
water the curious spectacle which has often been
seen in Polar latIudes OF these monsters peughing
their way against rapid current loaded with heavy
pack Ice aud in the very teeth OF strong gale OF
wind, can be readily understood on the theory that
the surface current Is shallow, and the drifting
colossus Is only obeying the mandates OF deeper
and more powerful agent
DURATION OF ARCTIC WINTER.
Lieutenant Schwatka also read short paper
the duration of the Arctic winter. Tho generally
pecially in the higher ATTITUDES is long dreary
one OF perfect opaque Darkness not strictly cor
rect. In latitude $50 20 90 n, the highest point
ever reached by man, there arc four hours and
forty-two minutes of twilight on December %. the
shortest day in the year. ill the Northern Henri
sphere. In latitude $40 27' n. the highest point
where white men have wDtered, there are
six hours and two minutes IN the
shortest day. aud latitude S4o 81 N, 172
nnt
ham reached, and 32S geographical miles from that
point. must yet be attained before the true Piu-
tonic zone that one III which there Is no twilight
whatsoever, even upon The shortest day of the year.
can be said to have been entered by OF course
about the beginning ana ending OF tins twilight, IT
is very feeble and easily eXInguIshed bV even
the s ghtes mSts but ncycrthcl II exists, and Is
quite appTeCiab.e clear cold days or ii tights.
properly speaking. The North Pole itself Is only
shsouded IN perfect biackuess from November 13
10 January %. a period of seventy-seven days.
that he has set lsupp0sing a circum-
polar sea or body of water unlimited to visiou) on
September q, not to Tise until March Is, for that
particular point, giving period OF about fifty days
OF uniformly varying twilight, the Pole has about
1SS days OF continuous day light, 100 days of vary
ing twilight, and II Of perfect inky darkness save
when the moon has Northern decllnatlonl in the
period OF typical year. During the period OF a
little over four DAYS, the sun SHINES continuously OF
bOth the North and South Poles nc the same time,
owing to refractlon paraaX, semi-diameter and dip
of the horizon.
THE TURQUOISE or NET-MEXTCO.
Professor Silhman read a paper in sequence Of his
paper of the preceding day the structure Of min
era veins. and explained the formation Of the tu1-
QnoIse OF NewMeXicO. He also presented interest
ing chronological facts concerning the Pueb0s Or In
dian peans Of that country. He exhibited suumber
Of domestic articles recently found in excavations
at Mt. Chalchuitl in Los Ceriios about tweniy-two
miles southwest of The ancient town Of Santa Fe.
Among these were a large stone hammer Of The hard
hoTnblendlc andeste of which the mount aims of The
country are largely formed l3np q p0,tery IDOL
such as arr manufactured 20 this day; 4 spoon made
Of shell perfect specimen of pott6EV DISH and
some of the bones OF the Pueblos Indian ;iuers,
VINO were killed IN 1850 by the fal Of le1ge section
Of Mt. Chalchuin winch had been undermined by
them. These articles had been c0yeTel III The
cavernS for 200 years when found The rocke hich
form Mt Chachultl-the Indian name OF the tuf-
guoise--are distinguished from those OF the SUI
heir white color and decomDOsed appearance
closely resembling inf and kaOn and giving eyl-
ience OF an extensive and profound alteration, due
PROBABLY 10 the escape through HEM, at tins point
IF heated vapOr Of water and perhaps Of other va
oors or gases. by the action of which the original
crystalline structure nI me mass has been completely
icCOmpOseG or netamOrDhOSed, with the Production
If new chemical compounds Among these The tur- |
luOse Is the most conspicuous and important. III !
he seams and cavities Of tins yellow sh-wiite and
laohn-ike tul1aceOus rock the turquoise is found |
u tin YtIn1es and ntte balls cOilcrctions called
nuggets covered on tue exterior with crust OF |
he nearly Whlte iuH, ana SHOWING on Gloss fracture
he less valued varieties OF the gem more rarely /
fernc iinr skybue stones OF higher value for orna-
mental pufpose.. Ii is easy % see these bua stains
Ii every direction among these decumUOscd rocks
,ut The turquoise IN masses Of any commercial !
'auc Is extremely rare, and many tons OF the rock
nag BE- bIOkcn without finding single stone which
JeWeIler or VIItuOsO would yaue as a gem.
That considerable quantities OF the turquoise were
btaiued can hardly be questioned. 1ho ancient
ieMcans attached great value to this ornamental
tone, as tho lDd3ue 90 10 this day. The familiar tale
I the gift Of Iar-e and costly turquoise By Monte
anna to COIDcz ior he spanish crown, as narrated ]
= ClaygcrO IN his history OF Mexico, shows the
lgh value attached 10 bis gem. Ii is not k own
bat any other locality In America has furnished
lrqu0ise IN any quantity. The origin OF the tur-
UOlsc OF Los Coros in view Of late observations
Not dou otful. Chemically. ii is ashydIous alumni
nm phosphate. Its blue color il due 10 a variable
nantIty of copper oxide derived from as,oci-
tcd rocks. The CerillOs turquoise contains
fli.