National Republican., 1885-01-20

The specimens Of augiteandesite when least
changed are Of o pale green color Most OF the
specimens, however, are very decidedly green
resulting from tho alteration Of the pyroNeulc
constituent In the ground mass. iPorphyritic
crystals Of tue feldspar aud augite, especially
the former, are occasionally developed In
great numbers They are always present, be-
coming prominent in tho thin section. The
sprnkliugs OF augite, although not so numcr.
ous, are sometimes developed I'm the form of
short thick prisms half a cCntimcter In length
appearing like little nOdules upon the iraC-
turcd surface, Under the microscope II is seen
that the pOrphyritio crystals are lmbcdded iua
ground mass Of iedspar, augito and magnetic.
The small icldspars prCdOmluatc and usually
have the long lath-shaped form with bosaltio
arrangement, but not infrequently they are
more nearly equllateral, giving more or less
granular appearance to the ground mass, The
Huglle when we'll crystalliZed frequently has
the lateral plnnacoidal planes most promi-
ncntly developed, producing form which Is
most common for hypersthenc, us shown by
Mr., w. Cross and myself, when hypersthene
and nugite occur together. A careful study Of
al, the sections, however revealed nothing but
mbnoGlinic pyroxenc, which ~ evidently
nugite, In the ground mass the augite Is
granular and later product Of orystalliZatiOn
than the foldspar, between which il Is olten
clamped. IL Is sgenerally altered TO chloritic or
hornblendc substances of q green color, with
but slight traces of hbrous structure. The
same grcenifh material sometimes forms beau
tilul peeudOmOrphs after tho large pOrphyritiC
crystals of augte Magnetic occurs IN abund-
ancc generally In irregular grains, but oitcn
In regular OCtahodron, uniformly distributed
throughout the mass. The rock Is for the most
part almost hOlucrySiallino, with the ground
mass mighty altered, but two of the specimens
which belong apparently to the same group Of
uugite.andesltos, have large prepondernnce OF
RmOrphus matter, and are 50 fresh as to deserve
special mention. They arO distinctly banded,
aud mt first sight look US though composed
of thin layers aud iilnmcnts of coal alternat-
lug with sheets of sediment. They so closely
resemble tllms OF coal In the cretaceous strata
OF northern California and Oregon ns TO be
very deceptive. Upon closer examination
however ihe black substance which looks
like coal is readily proved to be volcanic glass
Ia films, shrcds aud nOdulcs alternating with
bands In which crystalliltion has already be-
gun. Under the microscope II seems that the
CLASSY base prevails throughout the whole
mass, In section cut perpendicular to the
banding, by transmitted light, the glass ap.
pears OF various colOrs, from yellow to very
dark coffee brown. IL frequently shows n dis.
tinct lluidal structure as IN the lipnritcs on
vcloping small fragments of other rocks or
sparingly crystals of tedspnr and augito which
loated In the magma. II does not contain
the flood Of micrOlites, whicn are sometimes
abundant in CLASSY nuglte- -NndesitCs, but Is
lull of pearitic cracks, which being filled,
crystalline matter between crossed nicOls APP
pear MS minute films of light ramiiying the
amDrphous mass. In ordinary light the glass
Is seen to be mottlcd with small light colOred
spots, in many of which dOubly TefrGcting
points are plainly visible, indicating centeTs
banded forms of CLASSY layas are not uncom-
mon upon the outskirts of lava flow, and arc
not necessarily associated with the lava of any
particular chemical constitution. | have
found them abundant upon the borders of
lipartite in the Troad, rs well as beneath q
flow OF busalt in northern California.
The auglte.andesitos of the collection are
for the most part compact, but occasionally
amygdalOidal with amygdules of radial
hbrOus ilatrolite and brilliant lamellar apophy-
lite. The mass giving minerals of these rocks
are undoubtedly triclinc feldspar and augite,
ot which the former is by inr the most abun-
dant. Besides these, accessory magnetic Is
generally present in considerable quantities,
and well formed crystals of apatite occur spar.
ingly. Where tha rock Is highly altered,
quartz, calcitc, and various zeolites may be
found.
The volcanic tufas, few of which accom-.
pany the collection are composed chiefly OF
altered ashy material, among which one oCca-
slonaly recognizes the peculiar curved frag.
mcnts OF, volcanic glass, with few Of plagio.
case and augitc.
Three OF the specimens examined were
| found to be basalts. They are compact, very
fresh, and almost holocrystalllne, with few
| Of Oliylne embedded In the general web of
triclinic ieldspar, augite, oliyine, aud mag
| netite.
1t is interesting to note, in this connection,
| that this small collection throws ray of light
| upon very important group of rocks In this
| country. Hypersthene-Rndesite is more abun-
dant and more widely distributed in the west
| ern part of the United States than anywhere
| else on the earth IL occurs as far east Hs Col
| Orado but the limits In other directions have
| not been found, even approximately. The col.
lection just described renders 1t probable that
| the hypersthcne-andosites do not extend MS far
| south as Central America; otherwise we
should at least have hypersthenc associated
with the augite. Very respectfully, your
obedient servant, j. $. DfLLEn,
| Assistant Gcologist.
This re port to Maj. Powell, the Director Gen
cral of the United States geological survey
on the structure of the dividing ridge OF the
intrinsic scientific merit which is sufficiently
guaranteed under the signature of It's able
author, Mr. j. S. Diller, but because II makes
this fact known TO the world, that there Is
perhaps no other region upon the earth with 50
little accurately known of Its petrogrnphy u,
the belt of land joining the two great cont
nents of North and South America" II seems
therefore that NJ. dc Lcsseps started his cOlos
sal undertaking of oXcavuting lj0,00O,OO0 cubic
yards from the summit OF the isthmus to thirty
feet below the sea level without an accurate
knowledge Of the photography with which he
would have TO deal; In other words, he literally
built his Panama project upon sand; for the
estimate of this canal was based upon The
sandy excavation between said and Sucz, thar
| which II is hard to conceive anything mort
dissimilar In structure, in climate, in rainfall
| and In labor facilities than Panama, as NJ. dC
Lesseps has had abundant opportunities t
prove, and only found out when too late Il
| remedy.
Shakespeare tells us that ave caaao, all com
ndnd success bW ire can do ir1dt IL Ul0re-en
dedrOr 10 descrre a." Judged by this rul,
alone. the failure of the Panama canal is {
ioregone conclusion,
NICARAGUA.
/ do not propose TO so into the particular
| OF the engineering aspect of the Nicaragua
canal, OF It's physical geography, that srea
man, Commodore Maury, has dealt exhaust
| lively In a letter addressed to me some year
ago, which is heartily at the service Of tn,
United States. / shall content myself b!
merely saying that the feasibility of the routI
is assured, and that the experience hay,
: gained by repeated visits and explorations i
, also heartily Mt the service of the UnitcC
States. Moreover. take this opportunity o
saying unreservedly that cordially wish tn,
government present aud to come, every pos
/ sibe success in their work across Nicaragua
undertaken, IL seems to me. in the Interests o
| all the world.
, cannot understand any feeling of jealousy
much loss desire to check progress, on the par
: of the politicians who now govern old Eng
land. l laid all my work, my Interests, anl
} my concession Mt the feet of the then Englisl
government without the hope of reward; th
kHdOs OF opening the gate tue Pacific beinl
: all | required. My offer wa not accepted
presumably for good and substantial reasons
{ aud is, therefore, an GslOppd upon any dog II
I the Inanger policy, II such exists? which
doubt most certainly no such feeling can b.
found in the mind OF any real statesman, tn
. Clayton.Bulwer Treaty no'wlthstAndl TO
putting aside the well known legal axiom tia
"the necessity for the law having ceased tn
law also ceases" chat musty document in n
sense whatever precludus tho United State
from arrangingH strictly business deed ofparl
nershlp with Nicaragua, whiCn II Il earnest,
. TO be hoped Will soon be duly executed by til
Senate OF tho United States.
There Is only one part of that treaty whicl
has any significance NJ all IN the present juno
ture, and that is contained in the last para
/ graph OF article l, namely, the understnndu
that neither the UulteI States nor GrGa
5 Britain will take advantage of any intimacy
or use any alliance connection, or lntucuc
that either may posses with any state or COY
ernnent through whose territory the sai,
canal may pass for the purpose of acquiring o
holding, directly or indirectly, for the citizen
or subjects OF the one any rights or advantage
i'm regard to commerce or navigation thrO lgl
the said canal, which shall not bG offered Ol
+ the same terms 20 the citizens or subjects O
, the Other"
This point can be easily and satisfactorily
scttlul by scratch of the pen. Let the UnitcJ
States take the graceful aud friendly step q