The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1908-04-03
Tar on Roads.

AS direct result of successful ex-
periments with oil for roads in Cali
fornia-and in Oran, Africa, and sew
eral towns of Algiers where aloe and
maSSot oil were uSed-road builders
took up the question of employing tar,
either alone or in connection with oil
for road surfacing. in France a mix
ture of tar and oil was tried in 1900,
and by 1901 such good effects were OBJ
tanned with various tar mixtures, that
many miles of roads were surfaced
with them. The French engineers pur-
sued the subject with intelligent per-
severance and they secured some
ideal roads for travelling. The tar is
applied hot at 210 degrees, and only
in dry weather. After the tar is ap-
piled, a sprinkling of sand is made
over the surface to harden the mix
ture and to prevent slipping of horses
and vehicles. By the addition of heavy
oils, the tar is hardened more quickly,
and the road thrown open to general
traffic. All dust and mud are elimi-
mated by the tarring process, and the
roadbed itself is kept from injury by
heavy traffic. The waterproof char
acter of the tar Surface keeps the
water from entering the roadbed, and
thus eliminates one OF the most des-
tructive agencies of highways.
IN England tar is also used quite ex-
teRsively for the maintenance of the
roads, and in this country it is also a
well recognized practice One of the
first applications of tar to the surface
was made at Jackson, Tenn. The sur
face lasted about seven or eight
months. In Montclair, N j., a mix
ture of tar and screenings was tried
in 1904 on a steep grade, and for a
year practically no wear or tear was
noticeable on the road. Since then
number of other roads in that town
have been similarly treated at a cost
OF about seventeen cents per square
foot, including the cracked stone and
screenings. The tarring itself cost
only f1ve to six cents per square foot
In several other New Jersey towns
and on Long Island, roads are now
being treated with tarred surface for
eliminating dust and mud and for the
protection of the road itself.
| The difference between the method
of tarring the surface of roads in
France and this country is in the use
of sand screenings. In France they
merely sprinkle sand on the tar after
it has cooled a day or two, but in this
country cracked stones or screenings
are either mixed with the tar OF
sprinkled upon the surface, with the
purpose of incorporating them as
much as possible with the tar. The
French roads are excellent and form
a dry, dustless surface, but they dc
not last as the American roads OF
equal excellence. The tar and screen
ings, when properly mixed together
form sort of cushion, which greatly
reduces abrasion.
The use of tar in territories where
there are ample rainfalls is far sup.
erior to oil, for the latter then forms
an emulsion with the water, which
does great damage to vehicles and
clothes. 1t makes the surface mushy
and resprinkling is necessary at inter.
walls. But in dry, hot, arid regions the
oil Is superior to tar, and accomplishes
the object of laying the dust and form
ing a smooth compact surface better
1t Is consequently question of eli
mate and typographical conditions
which must determine the use of ma
terials and methods In any part of ths
Icountry.-Scientif1c American.