The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-12-17
The Harbor Commissioners at a
Standstill on the Rock
Question.
GOING TO OUTSIDE QUARRIEs
Scientific Analysis of the Nevada
Sandstone Mentioned in the
Lowest Bid.

Quest for suitable masonry for the ferry
depot bu Hiding, and the stone wall stands.
OF the bids received that of Charles f.
Mccarthy, secretary of the Pacific Bridge
COMPANY, was the lowest, and, under the
provisions OF the special legislative enact
ment, can only be considered. His bid, or
set of bids, was as follows: Depot building,
to be constructed of Nevada sandstone or
tuffa. $2lS, 600; of Arizona red sandstone,
1927 600; OF Oregon gray sandstone, $3.50, 900.
The Nevada rock, being the lowest BID,
was taken into consideration by the Com
mission, and Professor Hilgard of the
State University was asked to make
scientific examination of samples sent him.
The following is his report:
The rock has evidently been formed by the
hardening Of q volcanic mud consisting mainly
OF volcanic sand and lash" which, IN flowing,
has taken up and inclosed within the mass
small fragments of other rock and minerals.
The firest portions consist or volcanic glass
Dumice) intermiXed with crystals and frag-
mentS OF CLASSY feldspar and crystalline quartz
evidently belonging TO the volcanic material,
which is thus characterized as "trechyuc
tUif" Larger crystals of CLASSY feldspar and
quartz, grains of chlorite, plates OF mica, and
blackish, partly decomp0sed crystals OF horn
blende or angrite are also present, also some
rounded grains of dark-colored quartz. The
rock fragments Enclosed are mostlyof such re-
sistent rocks as quarteze .shales, or gneiss, and
angular.
Aside from these Enclosures the rock is very
compact and uniform and fine grained and
soft enough TO be easily worked. Its pinkish
TINT is due TO Il little ferric oxide (red ochre),
therefore entirely permanent. 1t is dissolved
out readily by muriatlc acid, leaving the stone
q clean white. But even q siX-hour treatment
OF the rock by muriatic acid at steam heat tails
TO disintegrate the surface or affect sensibly
its hardness or structure. The acid dissolves
out, besides the iron, SIN all amounts OF silica,
alumina, lime and magne STA, due evidently to
the presence of some eco little material. No
ferrons compounds capable of further change
by atmospheric action are present, and no
pyrites nor carbonate OF lime.
The rock thus possesses the elements OF tena-
cious resistance to weathering in the volcanic
glass, the quartz and CLASSY feld spar cemented
mainly by siliceous cement practically un.
acted upon even by hot muriatic acid and
therefore not liable TO be acted upon by the
acids OF the air. The rock Enclosure, so IA as
they have come under my observation in the
samples submitted, are likewise OF refractory
materials and seem to be quite firmly cement
ed within the mass. Among ordinary build
ing stones 1t might be classified as ''soft sill
ceous sandstone"
The lightness OF the rock is due to its poros-
ity, in consequence OF which it absorbs about
one-ejghth OF its weight in water when i'm
mersed. 1t should ther etore, like brick, which
absorbs the same or more of water according
TO its hardness, be Wetted in LAYING masonry.
E. w. HILGARD,
Director OF Experiment Station.
This test of samples sent to the univer-
sty indicated that the stone was fairly
durable for the purpose required, but 1t IS
alleged that the quarry Is undeveloped
and it is totally unknown at present how
much rock it will supply toward filling the
order for about 500 carloads, which it is
estimated will be required. Moreover it is
not California material, and this is an I'M
pcrtant objection.
TIE Arizona or Flagstaff sandstone is a
rel rock that has peen used in many build
ings in this State and is highly recon-
mended. But an objection comes in the
report that it will not stand the practical
test, notably in the walls of a hotel in this
City, where this material has been used.
Here it is alleged the large stones are dis
migrating under the weight of the great
house and the moisture of the climate.
1t was also stated that the walls OF the
Los Angeles POstotIice building, in which
this rock had been used, had cracked, and
that the feEce surrou nding the residence of
Henry Croker in this City was crum bling.
The agent of the Ariz ona quarry, who was
present before the com missoners yes
terday, laid the failure OF the stone to
stand tie test to the faulty construction of
buildings.
The same fault has been found with the
Oregon gray sandstone, and one Of the in
stances given Is the Delmonico building on
O'Farrell street. near Stockton, where it is
said the stone shows signs of disintegra-
ton.
The rejected bids, while calling for Cali
fornia stone, were placed too high, and
whatev er the desire of the board to use
q home product, could not be taken into
consideration under the law, as only the
lowest bid may be accepted. This is the
stone wall in the way of the Commission.
1t is reported, however, that ii Mccarthy
is given the contract he will substitute
other stone if it can be doae without ex-
ira expense to himself. As it is the board
must accept his Nevada sandstone offer or
advertise again for bids.
The principal opponent OF the outside
Quarries is the sandstone deposit near
Niles, in this State. Professor Hilgard
gives the following analysis:
l have examined samples OF the rock from
Stony Brook Canyon, near Niles, and find it 20
be sandstone, with grains OF quartz, black
mica, limestone and feidspar. These are
cemented together mainly by a zeolitic
cement, together with q purely siiicic one.
The minerals OF which this rock is COM
posed are highly refractory to wealth ering and
none of them are liable to change of color
None of the rock contains any iron pyrites
which might discolor or disintegrate it.
The cement substance resembles closely
that of concrete made with hydraulic cement,
and Il is therefore more liza bic 10 harden than
TO soften from exposure TO weather..
From the chemical standpoint consider the
rock very durable one
William Farwell, the representative.
was before the board yesterday and pre-
scented the claims OF the Niles stone on the
plea OF a home production. He held that
the specifications could have called for a
California product, and 1t was in the
power of the board 20 have insisted upon
that condition, without going to Oregon,
Nevada or Arizona for material that this
State could supply.
Mr.. Colnon stated that il would be we'll
for the board to visit Los Angeles, Sacra-
mento and other places where stone had
been used in large modern buildings and
carefully note how the material was stand
ing the practical test. Mistakes have been
made even after careful test, and the ma
terial that was to last for ages in the walls
of great structures utterly failed when put
under the tremendous weight of great
buildings.
Attorney Ford of the board gave as his
opinion that the Commission could safely
enter into one or more contracts for the
different subdivisions of the work desig-
mated in the statute without at the same
time entering into contracts for the con-
struction of the Union Depot and ferry
building.
The board adjourned till this morning at
10 clock, when the subject of the Risdon
Iron Works bid will be considered.