Vernon County censor. [volume] (Viroqua, Wis.) 1865-1955, 1908-01-08
TAR AN EFFECTIVE !:
ROAD PRESERvER
USED BY BOSTON METROPOLITAN
PARK COMMISSION.
GIVES DuSTLESS SURFACE
Results as Described by Chief En-
pineer John r. kablin-Faets OF
Genera! Interest-Much interest
Lies in New Methods Of Highway
Construction.


against the dust nuisance, In which
highway authorities are engaged every
where that there are improved roa1s,
two general lines Of progress nave
been developed with considerable sue
cess. On the one hand are those who,
By the use of a substitute Tor water
sprinkling, have sought to lay the 4dst
and preserve the roads, while in the
other camp are those who have aimed
to construct a permanently dust!ess
and durable surface. In the first di-
vision may be grouped the calcium
chloride and oil emulsion advocates.
Both these treatments require fresh
applications every few weeks, and
must be renewed each season. Their
advantages inciIde cheapness (the
cost being less than water sprinkling)
and ease of application.
Among those who have aimed at
more permanent effects, the metropol
itan park commission is the leading
representative in this section. 1t has
Tarvia, Asphaltoiline and other sub
stances which tend to rm smooth,
durable road surface, which is dust
less all the time and which will last
with very little attention through one
season, and the effect Of which will
not be destroyed between seasons.
The road preservation work OF the
Commission is in charge of John r.
albin, chief engineer, and he has fur
nfshed the Transcript the following
statement of the results attained.
The use of coal tar and oils for the
preservation OF roadway surfaces and
the suppression of the dust nuisance
has been tried on portions OF the
drives of the metropolitan park sys-
ten. In the construction JI macadam
roadways the usual Method Is to put
on the cruslcSa. stone in layers OF
bindinggravel, and bonded together by
rolling with steam roller The top,
or final Iayre, is rolled until it fills the
voids at the surface and forms hard,
smooth wearing surface for the road
way.
Before the extensive use Of auto
mobiles the ordinary wear by steel
tires and horses shoes on the stone
provided sufficient binder to take the
place of that blown away as dust or
washed of by surface water, and the
roadways maintained their smooth,
hard finish until entirely worn out by
the traffic. Since the automobile has
come into such great use, the miantel-
ance of macadam roadways, and al so
Of gravel surfaced roadways, has be-
come a much more serious problem,
although the latter are not so rapidly
destroyed as the former on account OF
the even texture of the material
throughout the whole depth of the
surfacing.
The suction of the larger ruoOer
tires of the automobiles raises the bin
der from the surface of the roadways,
and it is blown away as dust or wash ID
into the cutters. Over so per cent OF
the travel is of this nature, especia4.y
on the parkways, which are used al
most exclusively by pleasure vehicles,
so that practically no wearing of the
stones occurs to provide more binder
to replace that carried away. Consc-
quently, the roadways are soon str D.
ped of their surface. then the fine mat
erial is sucked out of the spaces be-
tween the stones, and stones become
loosened, and finally the roadway be-
comes full Of holes and breaks up and
expensive repairs are necessary.
II this stripping of the surface can
not be prevented It becomes necessary
to repair and sometimes evn to CON-
pletely resurface the roadways at least
once, and in some cases twice, year,
depending upon the extent of the ira
vel to which the road Is subjected,
This condition appeared in serious
form on the parkway roads about tn :
middel of the summer Of last year,
1905. Investigation was Immediately
made to ascertain the best methods OF
preventing the destruction OF the road
ways. Various treatme were con-
sidered, and 1t was decided to make
specially prepared coal tar known as
"garvia"
In the treatment Of the roadways
sith this material, the surface was
first swept clean with street sweeper
AMI scraped where necessary, to re-
move all loose material. The "Tarvia"
was furnished in tank wagons having
a ca,,acity of from FIVE hundred to six
hundred gallons at a temperature OF
about 200 degrees Fahrenheit and was
fiowed upon the roadway by means "
a one and one-half-inch rubber hose
attached to the rear end of the tank
wagon IT was allowed to flow only
a. fast as the men with push brooms
could spread 1t. In from four to six
hours after the material was spread
upon the road, this time being allowed
for It to penetrate the surface, crushed
stone screenings were spread in such
quantities as were necessary to alb
sosb the surplus tar. After the
screenings were applied to the surface
Generally, the results of the treat
or twice over. and was Immediately
opened to travel. The work wae
quickly done and with very little fu-
terTuption to travel.
For a short time after the treatment
SA~-sn w~az a uft~hf amount NJ An ~