The sun. [volume] (New York [N.Y.]) 1833-1916, 1906-12-02

with distilled tar. The usual process
is 10 sweep the road free from dust, apply
the hot tar with an ordinary watering can,
brush IL over so as to work 1t into all the
suface hollows. and then TO cover IL with
a fine gravel to prevent il sticking to the
tires Of passing vehicles. 1t is vefy neces-
ssry that this should be applied only in
very hot, dry weather, and in fact this
dry weather should nave been continuous
for at least ten days previous, so that the
water has been completely dried out Of
the road. When this tar is applied for the
first time a second coating ia necessary
about a month later, and after that il 10
the practice to apply one coat each year.
interpreting on this system is very ef-
fective for about six months OF summer
weather, after which it rapidly deteriorates.
and by the end of twelve months the tar
has TO all intents and purposes disap-
peared. In the districts where this system
has been applied every one has felt the
immediate advantage OF the absence Of
dust, and it is only lately, after a longer
experience, that the real evils OF this system
have become apparent.
THE first Of these evils Is a terribly greasy,
Shiny mud in the winter months, which oon-
tdluh n CtIbdAh Emporium VI IaLI buAAhtucub
to ruin any clothes on which it may drop.
This greasy mud is far worse for side slip
than any which motor vehicles have pre-
viously encountered, and It probably has .
deleterious effect on the varnish OF cars
and carriages. 1t also treads into houses
on the wayside and ruins mats and carpets.
Tho second evil has come to light recently
in the shape of complaints from people
Il.,.o. ~ tho aida ~ rNa6a that haua haa,
thus treated. At first they were rejoicing
in the absence OF dust, so that they could
leave their windows open and enjoy the fresh
air, but they have been struck by the fact
that all their hnen has gradually become
a dirty color which no amount OF washing
will remove. Examination shows that there
is a slight dust raised which contains a pro-
portion Of tar, and that this falls In almost
imperoeptibls quantities, so that its pres
ence is not at first detected. : = That this
gradual spreading Of tar must tax place
will be obvious from the fact that the whole
OF the tar painting has disappeared at tho
end Of twelve months.
The best own material for this pur-
pose consists Of blast furnace Stag, broken
while hot. and Immediately Immersed
in hot tar. The tar oils penetrate right
through he pieces Of broken Stag and
greatly modify its nature, 50 that under
the steam roller 1t consolidates into q homo
geneous waterproof covering. Very CON-
LTdOltJOTy TNsuAtb HdNO DCCl kcNOEutu ATOIn
the use Of tarred Stag. and investigation
has shown that much blast furnace Stag
is overlimed, and when made into a road
surface the free lime slakes and the coating
breaks up. The Stag resulting from the
preparation of forge pig iron is not over
lined in this manner, and should be the
only Stag used for the purpose. There is
a strong feeling that Stag Is too soft a ma
terial 10 long withstand heavy traffic, such
as traction engines and heavy motor wagons
and its length Of life under the conditions
prevailing on many of the main roads Of
this country is still a doubtful quantity.
Probably its use will show an economy
in some districts, but not in Others.
Some firms are also introducing water
proof road materials prepared from lime
stone treated in som way with tar. Lime
stone il an absorbent material, and the tar
adheres to it very readily. The resulting
road surface Is very good, but again, the
material is of a somewhat soft nature,
and its life under heavy ira fic remains to
be proved. The application Of tar, whether
in a raw state or treatsd by distillation, to
form a waterproof granite road, has not
been very successful. Great care is neces-
sary in the first instance to thoroughly dry
the stone, and even then there is a difficulty