The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-11-03

material is the ingredient which seems to
give the necessary toughness and elas-
ucitv to the bitumen when mixed with
sand. The bitumen which we have separ-
atAd from this material is only fairly
elastic but withStands a temperature of
120 degrees Fair. without exhibiting any
particular signs of softening. When heat
ed to $50 degrees Fair. ana pressed into
briQuettS it forms a fairly firm block, buta
on cooling becomes brittle and readily
crumbles. Such material as this will not
make q good. durable roadway. Withs
reference to samples No. and g. we
find it impossible to separate any petro-
lene by itself. the material obtained being
mixture OF Detrolene and hydrocarbons
o;lS- Both of these materials melt at a
very low temperature, flowing when heat
ed to Sc degrees Fair. and are very soft
even at so low a temperature as 70 de-
grees. The bitumen contained we find to-
be entirely destitute Of cohesiveneSS and
elasticity. BriquettS made from these ma
terials under pressure, crumble to pow
der when heated to so degrees and fall,
almost to an ash when heated to 100 de-
grees- Such materials as these are abSo-
lutely unsuited for use on road-ways. We
enclose you for your information, a copy
of so-->e analyses which we have made
from bituminous rock mined in California
and all of which should be very high
class material. This may be useful to-
vc- for purposes of comparison with our
analyses of samples.
These samples were from the quarries
at Santa Cruz. Yours truly,
Appended to the letter was the result
of the analysis, showing the merits of
the material used by Mr. Hobson as
compared with the asphaltum from the
Santa Cruz quarrieS. In the compost
ton of bitumen the Santa Cruz ma
terial showed 4450 per cent petrolene
and $3.50 per cent aSphaltine. The
Utah product showed $3.50 per cent of
petrolene and hydrocarbon oils and
1880 per cent of asphaltine. Another
Utah sample submitted to Professor
Kingsbury of the state university of
Utah showed SO per cent of mineral
matter and II per cent of asphaltum-
PROFESSOR KINGSBURY'S AN
ALYSIS.
In a letter on the result of the
analysis Professor Kingsbury says:
"On submitting the asphalt rock to
a temperature of 300 degrees fair. for
about five hours, it lost 2.22 per cent
1t also lost it's Elasticity and became
more or less friable. Taking the sam
pie submitted to me as a fair average
of the asphaltic rock under considera-
ton, the material is no doubt inferior
to many other asphaltic rocks; yet. I
hardly feel justified in stating that it
could not be used, at all, in the manu-
facture of paving material for road
ways. In my judgment it could be
used along with other asphalts of
richer or better quality, and in this
way lessen the amount necessary to
import without resulting in the pro-
duction of an inferior article.
This is my judgment from the fact
that natural asphaltum varies widely
in the proportional quantities of petro-
lene and asphaltine. some containing
asphaltine in excess, while other as
phaltum has petrolene in great excess;
20 -rr-
cessfully the artificial asphalt in con-
nection with the asphalIum rock under
consideration in the production of a
durable roadway pavement. I could
hardly, however, advise that this as
phaltic calcareOuS sandstone be used
as herein suggested in large quantities
without at first giving a small quantity
a thorough test, and in this way find it
to answer well the purpose
1t was the result of these analyses
that caused Mr. Kelsey to notify Mr..
Hobson last Saturday to tear uD the
pavement already laid.
Chairman Goliath said he believed
Mr.. Kelsey's statement set out the
facts. He had examined the Utah
found that it answered the purpose.
HOBSON'S STATEMENT.
Contractor Hobson then made a
statement pointing 10 the clause in
his contract which required him to give
a rock equal to the product Of the
quarry at San Louis Obispo, Cal. Mr..
Kelsey, he said, had made all COM
parative tests with the Santa Cruz
rock Mr.. Hobson produced analysis
showing that his material, although not
showing as great percentage in as
phaltum as the Santa Cruz rock, was
equal to the San Louis Obispo product.
Mr.. Hobson also said he had told Mr..
Kelsey where to get samples for
analysis, and there was no excuse for
the city engineer to delay matters for
80 days until one-half of the work had
been completed.
In replying Kelsey said the sample
was not furnished him until Oct. I,
he repeatedly requested NJ
HobSon for a specimen.
THE CITY SECURED.
The board then, after some discus.
sion, agreed TO let Robson proceed
with the work, using the Utah product,
provided he would agree to let the city
retain $4,000 for two years out of the
contract price in addition to the 10
per cent. This was agreed to by the
contractor