The sun. [volume] (New York [N.Y.]) 1833-1916, 1894-01-24
SAVING sIONE LOGS
The Work OF Remarkable Mn Operated
by the GeoIo Iical Survey.

Iron, N, W0shHgton PosL
There are many novelties In the Govern ment
departments at Washington. and especially in
| the scientific bureaus. The most novel that
has yet been discovered 10 a potrifed lumber
mill operated by the Geological Survey. 1t ID
| an institution that has not many visitors. It's
location down In the basement Of the Survey
building on / street being rather out OF the
track Of the regulation sightseer but there
the Survey lapiduries grind thin sections OF
rock and minerals OF all sorts for microscopic
exam nation. and thore Is band saw. the in-
vention OF the Survey. that will cut anything
from hot butter to a quartz crystal
Lately tho scientists have been saving up
lot Of vegetable petr1iactions from Idaho. They
can carve up anything in the shape Of petri-
fed logs that they can get In f'ont OF their saw
ing machine Even the ossilled man oi the
dime museum would not be safe from them,
and indeed lately they were called on to cut
up n petrlled, woman. one that was on ,exhibi:
into one OF the damsel's lower limbs a. little
way they struck gas pipe, The netrihsd LADY ,E
scientists gave her up as a hard case. which.
In fact she was.
to the petrined lumber mill lately was known
as cycad, a sort OF vegetable parasite which
nogTished In me prenistoric forests Of ne ne
woolly elephants aud sabre-toothed tigers had
made their appearance In the tassnst s. Of the
local traditions are carried In Alexandria,
The cycads were practically an unknown GUAM
collection that had ever been gathered, some
small specimens having been secured by the
with the giant ZOO pound one that is now at
the National Museum. one OF the, small ones,
up to the Survey to have some sections made
for microscopic examination. lt looked very
much like q cocoanut with the husk on. and
was cut up almost as easily as though It had
The band saw used in the work is nothing
M than pnllaaa Rtaal batwaan
eighth and sixteenth OF an inch thick. rum
Ging at very " high rSts OF spssd over two
fed on the wire as 1t runs. and the saw comes
as near being an Irresistible force as anything
ton Of the wire saw In Inc survey It has been
copied by q number Of laboratories and lapl-
Diary establishments all over the country.
Beside the saw there are a number OF grind.
ing machines smooth iron plates revolving
water and emery. ON these plates sections 81
stone for m croscopical examination can be
@ a. tn Ii ., fe gee
under strong light. These sections are usually
not thSs pess sSf liz n
TO show the plan Of cell growth; ana slab was
ent almost as large as mans hand. This:
one side ground perfectly fiat, was trans terreI
TO g ASS plate. to which Il was fastened with
for study, It Is a very beautiful specimen.
showing in prismatic oolors the lines OF cell
partitions and annular layers like the rings OF
The iapidary establishment is one OF the
vey has In Working up the geology Of the
Gconptrg. Many OF the rocks That are met with
niS tne neia cahnIs ne NON esea
as the nature OF the rocks filing the different
sections OF the country has to be aseertained
mems carefully labelled, have to be sent back
TO the department in Washington Tor study
Three methods are used In the identi fcatiop
OF tho close-Grained metamorphic rocks that
by meas urinG the number and angles OF the
CRYSTALS, by chemical analysis 10 get at tho
microscopic examination. when. in the thin
sections . the cTystnilins, structure can 20 seen
the aid OF pSariaed light some Of the thin
stone sections mounted on glass slides are
II SSRS s s%pR
One OF the most remarkable Is one OF the rare
minerals, dumoritite. which has lately been
dlscoyered in Arizona. and Is what is known as
When Viewed under the microscope 1t seems
around al, a different angle some Of the blue
View The explanation is that when the lighI
rays pass thTough the CRYSTALS parallel 70 their
rays. Tut the light striking the crystals at
right angles TO the long axes, the blue raysaIs
Is oRy one am fxs sotG the
which the various rocks are recognized
one OF the minerals, Of which there are sew.
in the Geological surveys coliectlon OF slides.
is psTitotits. This gains interest from the
fact mat II is the associate OF the diamond in
all of the great African fields. Its finding by
lrof Lewis of Philadelphia in kentucky some
years ago caused great excitement. aud there
was some warm pros pecting for diamonds. but
none were ever found, Its congestion with
the African diamonds came from the fact
that when the peridotlte had como TO the
surface In a molten condition T. had beea
forced through the clsfts or faults" In
some very rich carboniierous slate Fields.
The hot rock had crysallizad the arbon Of the
sat g measures int diamonds, which are found
scattered along few yards on each side Of
the contact. What the diamond prospsetOrs
are looking for in this country ls a CON bina-
ton OF peTidotlte and carbOniferous States
Whether they will hnd Il or not e a question;
one OF the many seaTcLers after artificial
diane nls lately made an important discovery
that Is being utilized ~ the survey and ~
many manufacturing establishments where
abrasiycs such as emery and diamond dust
are In u.s.. The new substance IL known as
cart Oruudum, and Is the result OF passing z
strong current OF electricity through a mix
tura OF powdered carbon and Inc sand in q
closed retort. The chemist did not get dis.
monds for his trouble. but no may yet wear
them a. the new compound promises to prove
very valuable AND may possibly supblant
emery IN many commercial uses.