Evening star. [volume] (Washington, D.C.) 1854-1972, 1892-02-20

| through the casing ceases, a. the fluid finds al
4 easier path in the horizontal current than IL
the vertical column up the pipe, and no sam
/ pies can be obtained until the casing 10 driver
4 down below the drill point, and thus the wall
i of the upward channel are protected. Thes'
/ conditions frequently occur 5ust before rocl
l ia encountered as was the case in the two pitt
/ already sunk Of the site. and then the casing
can soon find firm resting place and there Il
no tendency on the part Of the cutting water
| The specimens that are brought to the sur.
4 face sink to the bottom OF the bucket that Is
| casing. and when it is desired to examine the
| products the water is poured carefully off and
the sediment preserved by being placed on
large sheets Of paper, 80 that the retained
water can be drained of.
| The samples are taken into the construction
| office on the north side of the square and dried
| over the stoves in a sauce pan. 1t is curious
cooking this, and produces all sorts of IN
MISUNDERSTANDING stuff, but ii is highly priced
by the architect and his assistants. When
thoroughly dried it is placed in small bottles of
white glass with wide mouths and labeled with
numbers corresponding with a tally sheet that
is carefully made up the results of the drill
ing are made apparent This sheet notes the
character of the specimens brought to the
surface and the depths at which they are en-
countered. From this memorandum there Is
prepared another sheet of drawings Of the va
rious strata that occur beneath the surface,
done IN the regulation style, with a certain
style of marking for clay. another for sand and
on through the different materials that are
found
GOING THROUGH ROCK.
When rock is struck the drill gets right down
to business and eats downward with slow but
steady precision that is admirable. The bucket
then shows either fine silt ground from the
face of the rock or particles of stone Clipped
off. An expert eve can easily discern the char
acter of the rock by these fragments, even
when they are as fine as powder, and strong
glass being brought to bear on them brings out
their characteristics with wonderful distinct
ness. 1t is thought that the rock found in the
northwest corner of the square is of that nature
known to geology as Schistose horneblend, or
bastard granite. The particles are hinty, with
sharp edges, and very pretty. The nature Of
the other rock has not been accurately esti-
mated, though II would be the natural expee-
tstion that it would very closely resemble the
horneblend.
Architect Edbrooke yesterday expressed the
opinion that there are traces OF gold in some of
the clays and gravel of the intermediate strata,
but this is not altogether surprising as it is well
known that there is gold to be found through
out this vicinity. Some small but handsome
agates have also been brought to the surface
from the gravel beds just above the rock
There will be a hole bored in each corner of
the square, and soon as the results SO
obtained have been formulated there will be
others located and the borer will go to work i'll
intermediate parts SO as to determine whether
the rock, should it be found IN the south end as
well as the north end of the lot, extends evenly
all over the site.
This work. is of the highest importance in
determining just what sort of foundation shall
be provided under the building. II piles are
used-as seems probable will undoubtedly
be driven to the rock and then all question of
the irmness of the structure will be set at rest.
There are some, however, who are of the opin-
over the rock there is no need for piling and
that solid foundation can be obtained by
merely concreting. There has as yet been de-
veloped absolutely no mud or muck beneath
the surface. and thus the presages OF the an
tagonists of this site that the place was a mud
hole and wholly unfit for the purpose for which
II Was selected are set at naught.