The record-union., 1892-12-01
CHEAP JOHN IMPROVEMENTS.
Streets and Sidewalks Should Be Of
the Best Material.
A Timely Subject Intelligently Dis
cussed by Edwin X. Alsip-
Bitumen for Streets.


make advancements that will indeed as
tonish her friends, as well as her silurian
enemies.
1 am really glad to see another step
made toward street improvement. An
outlay for bituminous coating will add as
much as anything toward giving our fair
city a metropolitan air. Now, that we
are talking of adopting an asphalt cover
ing for our streets, we should look well
into the matter and not make the mistake
OF other cities. Right here l wish to ask
that our Trustees require in all specifica-
tions a condition that all streets covered
with asphalt or bituminous rock should
be warranted or kept in repair for five
years, as in the original bid it will cost
but little money, while it will cost the
city great deal to keep them in repair.
l have, while in San Francisco, taken
some pains to ascertain the various kinds
of covering and for macadamiZing streets.
While this is a dry subject to many, vet
it is the most important to our property
holders, as well as our city, as once the
material is down it cannot be replaced
without heavy expense. l will here
predict openly, as l have often done
privately, that in that portion of the city
upon the high grade, where concrete
walks have been laid upon wooden
foundations, the latter will in few years
be all rotted out and we will be in a
worse condition than with the old board
walks; a new foundation of iron or brick
viii have to be put down, and the first
work of board and concrete coating will
have been a dead loss. This is the result
of doing things cheap, and is penny wise
and pound foolish. SO do not let us
make the same mistake upon street
n-l- 4 loTNf fagv fl,pAa1pr, eol,,
tion of street work and the City Fathers
of one should profit by the mistakes of
the other. Could |, in measure, be the
means of our city steering clear of some
of the mistakes of others | would feel re-
paid for my work.
There seems to be a confusion in the
minds of many as to the Difference be-
tween bituminouS rock and aSphaltum as
a wearing surface for streets. | think il
would be well to start out with the analy-
sis of the classes of material now in use.
To start in with the analysis of good BIZ
luminous rock such as was used around
our State Capitol grounds Is found to
contain eighty-tour per cent. of perfectly
clean sand, nine per cent. of parafine oil,
and six per cent. OF asphaltum. The oil
and asphaltum together is known as BIZ
tumen; the oil has very great specific
gravity, and in the analysis of the rock
none (of the Oil is distilled under 3OOo
nine per cent. is obtained. The oil is the
lie of the rock, giving to it great elastic
lty, which no heat We have in the sum-
mer will melt sufficient to cause it to
run. Good bituminous rock should al
ways giUe to the wagon wheel or horses
hOof, as then it will not break under
heavy weight, and consequently will
wear much longer. Bltumen rock that
does not give is of poor quality.
Crude asphaltum, such as is found in
California, contains from 40 to so per
cent. of asphaltum, the remaining part
being adobe. When laid upon concrete
surface it IS usually mixed while hot with
common sand, a small quantity of coal
tar being used as a fux. 1t is claimed
that the best and purest asphaltum comes
from the island of Trinidad, that being
the kind used in the East. 1t is mixed
while hot with powdered limestone. The
ravements laid with this seem to give
general satisfaction, the only thing
against it being that it becomes too hard
and is not sufficiently pliable. ! cannot
find that there has been any used upon
this coast.
The oldest piece of asphaltum work in
San Francisco was laid in 1856 on Golden
Gate avenue, between Octavia and La
guna streets. 1t was laid upon a macad-
am foundation and guaranteed for five
years. 1t did not stand and was covered
with bitumen. At the same time block
on the same avenue, between Cough and
Octavia, was laid upon the same founda-
ton with bltuminous rock upon which
hve-years' guarantee was given. / am
told that 1t was repaired but little. The
two samples were done by rival compa-
nies. The sphaltum-although, l am
informed, 1t was repaired frequently-has
entirely disappeared, while the bitumen
is still in very good condition and has
been but little repalred), although 1t has
stood six years. The only blemish is
seen in the gutterways.
Bituminous rock should not be laid
upon q smooth surface, as instances de-
monstrate 1t has tendency to slip and
buckle. In laying it the surface of the
foundation upon which it is laid should
be well cleaned before laying, as it will
slip after few years if it is not. By rea-
son of the macad2m not being well cleaned
Is the cause of the present condition of
some parts Of Golden Gate avenue, which
is covered with bitumen rock.
Samples can be seen of asphaltum on
Front street, between Market and Cali
fornia, ana SAMSON, from California to
Sacramento street, which was laid upon
concrete foundation; this was laid in 1891.
At the same time btuminous rock was
laid upon Front, between California and
Commercial streets. | am told that the
asphaltum had to be repaired often by
reason of holes wearing in it, as owing to
Its hard surface it breaks and holes get
into 1t, while the bitumen, owing to its
elasticity, gives and does not work into
holes. AS can be seen, when bituminous
rock is robbed of its oil it then becomes
brittle. a second coating of asphaltum
has been put upon Front street, between
Market and Pine streets, as the first was
unsatisfactory; yet nothing has been done
to the bltumen, and to my eye it's wear
ing much better and is in better condi-
uon. AS heavy teaming as is done in the
I nlted States passes over these last
named streets. While sufficient time has
not yet elapsed to fully judge of it's dura-
bility, yet to an unprejudiced eye it can
be easily seen which Is wearing the best
Neither bltumen nor asphalt should be
laid in cutters, as the ammonia from
horses urine and manure destroys them,
but the cutters should be laid for four or
five feet from the curbing with granite or
basalt blocks, as is done in Stockton. 1t is
not necessary to have thick coating, as it
is only put on to break the jar and lessen
the noise of vehicles. One and a half or
two inches wears better than thicker
surface.
From my observation l am satisfied
the best quality of bitumen will wear two
or three times as long as asphalt, and is
much less expense to keep in repair
In letting contracts the Trustees should
require samples and assays OF each COM
pany bidding, as | find there are inferior
qualities of bitumen.
Pardon the length of this article, but l
felt it of so great importance that | could
not say less. This article is especially
dedicated to our Trustees, and a commit
tee of themselves or citizens should visit
san Francisco and investigate before
adopting any one kind, and not make the
mistake of others. EDWIN K. ALsIP.
November 50. 1892.