The sun., 1910-06-09
SAILING ZEE HIGHWAY.
4 Meshod Recommended for Kssplns the
Dust Laid.
FrO- No Elp,rs sga, Hsious

Frol No Eppirs !sais Aoiors,.
The uses Of calcium chloride a. a dust
layer are Interestingly treated In the follow -
ING paper written some time aEO by Provost
hubbard of the United States once Of
Public Roads.
-Calcium chloride. Which IL obtained for
the most part a. a by-prOduCt In the manu-
iacture Of soda. has been used 10 consid-
erahle extent a. a dust layer. says MT
Hubbard IT Is a more hygrOseOpic than
ma gnesium chloride and can be obtained
AZ a moderate price In an almost pure state
Il Il sold either la solution or In solid.
fused or granular condition. Tha solid
material contains about p per cent. m0is-
ture and 7S per cent calcium chloride. While
the solutions run from q saturated cOndi-
ton to various weaker strengths. The
ordinary concentrated solution carries about
N per cent. calcium chloride aud has a spe-
cifc gravity Of / tOO. Both the solid ana
solution are sold on a basis OF the actual
salt content. aud the solid Is therefore
cheaper when the cost OF transportation -
taken into account Il can at the present
time be purchased at about si6 ton I. o. d.
lt points Of manufacture.
Calcium chloride has been used 10 a
slight extent IN the tinted states for the
purpose Of laying dust and when properly
applied has proved successful, The amount
Of salt and number Of applications required
10 Keep down the dust satisfactorily for a
season will vary greatly with local cOndi-
tiOns, but the exercise Of a little Judgment
makes II possible 10 obtain good results
with q minumim expense. Before constd-
eFinR ts advantages and disadvantage,
however. its method Of application should
no taken up
In most cases Il is applied for the first
time on he unprepared road. The sOlutiOn
Is sprinkled from an ordinary watering
cart. 80 that on an average gallon y
applied . square yard. although BY reEu-
lating the spread Of the sprinkler to aDOut
two-thirds the width Of the road the middle
receives twice the amount Of the sides " hen
The sprinkler passes over the road twice
While the centre receives double dpplica-
lion By this means there ~ a tendency for
the whole surface to receive an equal share.
owing TO the fact that rains tend 20 carry
the dissolved salt 10 the side Of the road.
rs or 10 per cent. solution II first en-
ployed, and a. least two Of these Applica-
lions are made IN the first week or two In
order 20 imgregnaie the surface thoroughly
The salt thus applied has a tendency TO
retain the moisture for a considerable
length Of time after an ordinary application
Of water would have evaporated On hot,
dry DAYS. however. the road does dry Oui,
espe' ially ON port ions unprotected by shade,
and it has been found necessary To feed the
salt by ordinary applications Of water
he number Of sDrinklinRH necessary will,
course cheaper TO feed the calcium chloride
already on the road with water than 10
apply a fresh solution each time the road
becomes dry In humid weather u Is often
A
time. as the sal, ahsOrbs sufficient moisture
from the damp night air 10 keen the road
In good condition throughout the su' yerd-
ing dav
Cium chloride j. washed out Of the road and
has 20 be replaced 10y fresh material sin
vle applications OF an OF 10 per cent ~oti-
ton applied ~ intervals VARYING ron two
10 five weeks apart, according 20 conditions.
are usually sufficient to maintain The proper
amount. and these may be made IN the
same manner as described for the fir-t two.
too rapid drying ~ the road s an indicn
ton that more salt u needed and a little
experience will soon enable the oVer~eer W
eNperiWeutrr 10 determine 'u-t how often
and lt Just what time 90 make a fresh applI-
'atlon. The same II also true with respect
20 feeding the -alt with water
The principal advantage Of calciuru
chloride ~ a dust LAYER are that u h. OdOr-
les and clean When present iU sufficient
quantity t E undoubtedly a good dn.t
or 10 q il fed occasionally with water I~ dry
weather While u i.true that the f1rr1ri .1u
oi mud in wet weather B.. rot le.rsued r''s
mud !, not more Objectionable than = .at
ordinarily encountered "a. not enuuru -aF
is pre- seut 10 give Il the undesirable uuali'.os
produced 10y me Application uf -.I water.
iu addition, calcium chloride teud- % diz-
tribute the moisture evenly over the road
.uriace and IL oan be easily and 0uickly ap-
piled IT. uEe. hae that of anv other good
dust layer prol0ngs the life OF a road hy re-
tanning the products of wear. and ,u some
cases u may b. chemical action increase J
the oementing value of the roCk powder
on the other hand. Il is not essent iallv !
q Tuad builder and 40 the end nf a season = I
treatment. while The road NAV be IN bet
Ter condition than at the Start. no add
Heavy rains are likely 10 wash mO-t NJ o.
from the road. and 10 a number Of showers
follow soon alter an appllCation much of
ts value will be lot Water does not .
hoWever. always carry aWav 20 much OF
the salt A. might he SUPPOSED, owing 10
he absorbent qualities ol many rock pow
der~ Another obieJtion 10 H. u-e is that
tn hot dry weather it requires feeding with
water -om@times ~ often a. once 4 day
ln common with al other temporary bind
crs which are applied ~ solution or emul-
SION t can only bc employed IN localities
favored with q convenient water supply
A. . rule u y slightly more expensive
than water alone. but when applied intelli-
gently according Ia system similar 70
nav AeEfttDFu me tuHi uf treat memi - IN
some measure reduCed IN one case under l
severe trafnC conditions on macadam
road he cost Of laying The dust for one
season vas reduced from three cents q
square ward with water alone 10 two and I
-even-tenths cents with The use Of calcium
chloride Six applications we're made .
two in June and one each In July. August T
September and October and on very dry
DAYS the road bad one light sprinklIhE I
with water fTOm bis treatment the dust j
was successfully lad throughout the sea-
son. while In prev iOus seasons foun.appliCa- /
: ions Of water q day often proved Ineffective I
! uder certain conditions therefore calcium l
chloride NAV not only prove 10 be a good /
dust LAYER hut economical A. we'll and .
eVei. " the cost y somewhat greater than for I
the 1ppltCatlou Of water alone tho beneficial /
effects produced upon he road will In many /,
Caae- more than compensate for this dlfier- |
enCe
Tue Fate Sf . Greek Piper.