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

! Washington, d. G., June 26.-The fol-
lowing report upon street paving in
Australian cities is Of interest in all
cities. Il is from the pen of Consul
General George H Wallace, of Mel
bourne.
The nature of the soil of Australia
made traffic over the roads of the col
ony extremely difficult; in the dry sea-
son they We're beds Of loose sand and
dust and in the rainy season rivers of
quicksand.
The first efforts at improvement con-
sisted in raising the roadway from 10
TO l. inches with earth from the sides.
leaving broad and shallow bitches for
drainage Over this roadway was spread
inches of stone, usually basaltic in
character, broken into to 6 inch
cubes; over this layer of stone, brok-
en- to IL by 2 - inches, was spread
inches deep. This was ''blinded'
with screening from the breaking and
the whole rolled solid with a steam
roller
The roadway was about 20 feet in
width, and cost for the stone alone
about As Tor 81 in United States cur
rency) per square yard, laid and rolled.
These roads have been found to an
GWer we'll where the traffic was not
heavy or continuous; but in the lead
ing thoroughfares in the cities not on
~ is their maintenance very costly, but
they are not satisfactory in durability
IN 1880 A. G.. Mountain. then surveyor
to the corporation of Sydney. New
South Wales, in report to that body.
! urged the paving of the streets of that
city with wooden blocks in place of
the matchmaking previously used,
! calling particular attention to the val
ue of Australian hard woods for the
purpose on account Of their tOughness
! and dura bility. Then followed a series
OF experiments to discover the prODer
foundation, the best method of laying
the blocks, and the value of different
kinds of wood for the purpose. King
street, Which is a short cross street in
the busiest part of the city, was paved
with eight varieties of timber, viz:
Eucalyptus rostrata), black butt HIu-
calyptus pilularis), blue gum Eucal-
yptus botryoides), box Eucalyptus al
bens), ash Eucalyptus virgata), cedar
(Cedrela australasia brown pine Fere-
nela endlicheriD and Baltic deals. The
first four We're hard woods, and all
We're native except the last, which was
from Sweden
Owing to fear that the hard woods
would prove slippery, the blocks were
laid with one-inch joints; but the width
OF joint has since been gradually re-
duced TO three-eighths of an inch, with
out any appreciate increase of danger
to horses. The foundation consisted of
a layer of Portland cement concrete
six inches thick, rendered on the sur
face with a coat of cement mortar.
on which, after a weeks interval. the
blocks-9 by 6 by 3 inches-were placed
trayersely across the street, with two
longitudinal rows next the curbs These
blocks before being laid, were dipped
in Kerosene tar; but, as it was found
that after a hours soaking in heated
tar the penetrat ton of the tar into the
hardwood blocks was only one-six
tenth of an inch, owing to the density
of the wood. no preventative treat.
ment was subsequently attempted.
The street thus paved was opened
for traffic in 1880, and in 1882 blocks
OF the different woods were removed
and the wear carefully measured. The
red and blue gums and black butt re-
tanned almost intact their original depth
hn
ash had been reduced about one-eighth
of an inch, the cedar and brown pine
about One-quarter of an inch, and the
Baltic three-eighths of an inch. In 1881
the cedar, being short in grain. had
broken away rapidly, and was. with
the brown pine and Baltic, replaced
by hard wood, and small renewals
were made of the ash and box. Ex-
cept the cedar, the blocks renewed
might have lasted Another year: but
they rendered the surface irregular.
Flinders street. in Melbourne. was
paved with siX-inch red gum blocks
in 1882. This street is the busiest sec
ton of the city, connecting the rail
ways and the wharfs, and the traffic
is of the heaviest description. Blocks
taken from the center of the street
in 1891 showed a wear of one-sixteenth
of an inch; but here, as in Sydney. all
of the earlier work was done with
three-Quarter to one-inch Joints. and
THESE We're calked with a molten pitch |
of tar and screenings obtained from
crushing stone for macadamized roads. |
which served the double purpose of !
holding the blocks firmly in place and
preventing surface water from getting
down to the concrete. The Joint has
since been reduced to five-sixteenths !!
of an inch, and the calking is now
done with properly prepared cement, |
as it was found that the pitch wore
away and the iron-shod feet of the
horses broke down the corners of the !
blocks, so that the road was disagree
ably rough and noisy.
The streets of the principal cities |
of Australia having the heaviest traf-
fic are now paved with Australian hard
wood, and where proper attention has
been given to the foundation and to a !
right selection of blocks the result |
has been most satisfactory. Although |
much of it has been down from eight
to ten years and subjected to the Sc
verest test the arch of the street is |
still well maintained, with an even sur
face, and drains practically as when
first laid
Both the climatic and traffic con-
ditiOnS of these cities are different from