Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1893-06-30

of .jarrah and karn for street paving.
Owing to the unsatisfactory results Of
previous experiments with oak, elm,
beech, and pine. there was much oppo-
sition to their introduction, but so far
they have given excellent results and
are being largely adopted for the car
riage-way pavementS OF London. From
: Engineering, published in 1892, we
learn that they have been put down
in Is vestrieS, and that wherever the
wood has been laid in a suitable man.
ner it has given the most satisfactory
results. Three thousand one hundred
and sixty-seven loads, each of 600
square feet, of jarrah and karri woods
were shipped to London in 1891 for
street paving purposes.
| In the earlier days of street paving
in cities it was customary to lay the
covering material upon an earth or
sand foundation, but the almost in
variable rule now is to lay the whole
breadth of the road with a layer of
cement concrete six inches deep and
arched to the conveXity necessary to
the locality. Engineers and surveyors
of concrete as the actual road pavement
and, if durability, evennpSs of surface
and eventual economy be desired of
the first necessity. This cement con-
crete, if of good materials and care
: fully laid, will practically last for
generations; it takes the weight of the
traffic and furnishes stability to the
street surface. Here, where the sandy
nature of the soil gives a natural drain
age and there is no frost to lift from
below the 6-inch bed of six or seven to
one cement concrete has been found to
be sufficiently heavy. 1t is extended
to the cutters, four feet wide, formed
of dressed stone cubes bedded in sand,
which affords the necessary expansion
joints.
! The half-chain roadways are of wood
on concrete foundation, us before de-
sCribed, with wooden cutters u inches
wide, formed of wooden blocks placed
in line with the direction of the street
an at right angles to the direction of
the other blocks, their surface being
two inches lower than the nearest
street block. These and the two adj
joining street blocks have three-quarter-
inch joints for expansion.
The solidity of iarrah and kari is
such that some complaint is made Of
their slipperiness during and Immediate
ly after slight showers of rain, but
this is provided for by slightly sanding
the paved streets at such times. At
all other times the horse ShOd with
a fiat shoe finds as good footing as on
paved streets.
1t will be seen from the following
figures that the first cost of thus paw
ing a street is heavy, but the total
expenditure in Melbourne in ten years
for maintenance and repairs amounted
to less than 1 per cent on the total
cost of the work:
Per
So. yd.
Karri blocks, 8 by 6 by 3.. $216
Jarrah blocks, 8 by by &c.,. 2.4O
SiX-inch cement concrete e to u
mortar rendering on surface. =. 1.56
Laying and grouting . 80
Excavation and removal average 1
foot and sllndries. .. 80
TOTAL S6.12
The above cost is for blocks delivered
in Melbourne, and it is probable that
they could be landed in cities on the
coast in the United States for the same
amount.
In London karri and jarrah have
worn four times as long as pine, and
are still down, thus avoiding the long
Interruptions to traffic which occur
every few years while the surface is
being renewed. The scavengerng can
be well and quickly done, and the SAM
tary conditions must therefore be bet
ter When it is necessary for any pur-
pose to break the street the cement
concrete lends itself readily to repairs.
The government of West Australia
has made a special effort to call the
attention of the cities of the United
States to kari and jarrah as Il paw
ing material by sending to the worlds
Columbian exposition an exhibit of
both woods. If possible to secure the
space in some much-traveled thorough
fare, it was the intention to have a |
section laid with full-sized blocks and
grounted joints on a cement-cOncrete
foundation, showing how and why the
cities of Australia have the smOothest, |
claanest, neatest, most durable, and
most economical street-paving Of any
Of the cities of the world.
The greatest difficulty to be overcome /
in developing the trade of the United
States with Australia is to secure
return lading. Most of the vessels
bringing assorted cargoes from the east
ern, and pine and soft lumber from
the western coasts of America loaded
with coal or leave in ballast, and the
probability is that cargo Of karri
or jarrah would be carried as return
lading at very low rate.
POLICE WAKE UP.