Los Angeles herald., 1907-11-03

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ing Of crushed stones. Such road be.
comes very rough ultimately, and at
present modified macadam system is N
use. Whereas Macadam declared his
formula to be invariable under all con-
ditions, French engineers do not hesitate
to employ piles, stones, brush or anything
else requisite to establish secure founda-
tion, or to slightly increase or decrease the
thickness of crushed stone where the soil
or conditions present special character
istics.
LAS every roadbed established directly
upon rock foundation Is hard, likely to
become rough and to wear out rapidly.
when such foundation Is necessarily en-
ployed considerable layer of earth is
interposed between foundation and sur
face The road materials being in place,
consolidation of the surface Is obtained
by rolling with cylinedr of about six
tons weight. The roadway Is sprinkled
continuously during this operation and
melange equal to 10 per cent of the volume
of broken stone, consisting of sand and
argillaceous material, is thrown under the
cylinder.
Surfacing the Highway
1.-THE most favorable moment for con-
structing highway is at the beginning Of
spring. The materials most difficult to
handle are pebbles and hard. unbroken
gravel. When such material is employed
there should be no hesitancy In using as
much as II per cent of aggregatng earth
and sand-the maximum prescribed
Broken limestone is most highly regarded
for surfacing purposes. after which in the
order given come silicious material, such
as quartz, when 1t is not friable; slick
and granite when the cost of crushing Is
| not excessive, basaltic materials If mixod
with limestone, pebbles and gravel from
mines or river beds. Limestone works up
| most readily, but harder materials, sucn
as slick or granite, last longer and give
less dust and mud The best stone for
road making contains a gangue of call
| careous nature which becomes manifest
under compression and provides much of
| the hardness and cohesion of the best
| French roads.
applications of hot tar well worked
| in with brushes will aid in prolonging the
life of any good road, and to that extent
| prevent the dust nuisance often intoler-
able in these days of automobiles. The
use of tar has been discussed in my
previous reports on this subject. 1t should
he understood that coal tar baths will
avail very little on old wornout roads
and that dust itself is detritus arising
from the disintegration of the road itself.
Consequently the only real remedy for
are virtually indestructible.
New Problems
"The chief concern in France is that
all preliminary and necessary operations
shall be thoroughly performed. When
embankments are made the earthwork Is
built up 500 to 7.S7 inches at time, aud
the successive strata are leveled, and in
the neighborhood of masonry, rammed.
Time and rain are given as little to do In
the matter of procuring solid construction
as possible Similarly every ditch is very
carefully cut at a proper angle, ranlmed,
and if necessary paved with stones.
Every dangerous turn Is protected by
stone parapet and stone posts are planted
one kilometer apart, with ten smaller
stone markers at equal distances between
the lSilometer stones.
"At each cross road there are sign
posts, always in order, and nowadays
(this thanks to the Touring Club de
France) there are indicators to remind
the traveller of dangerous curves, rapid
descents paved drains and the like Every
grade railroad crossing is protected by
gate with a watchman in charge night
and day.
''There are in France 23,656 miles of ma
tional routes, which cost $303,975,000 10
build There are also 316,S9S miles of local
highways built at a total cost of $685.
100000 of which the state furnished $751;
O6O,OOO and the interested localities $227,
100000.
Destructive Effect of Auto
''The advent of the automobile, with Its
destructive tires has placed increased
tasks upon the French roadmakers No
method has yet been discovered of pre-
venting the file-like action of the rubber
tires aften steel shod, upon the road sur
face. Coal-tar baths do some good espe-
cally in keeping down dust, or rather in
preventing its formation, but are by no
means generally applied, and only in or
near centers of population.
ION the other hand, the permanency of
automobile traffic Is recognized, and
wherever dangers present themselves 20
this method of circulation efforts are made
to mitigate them, either by directing pub
lie attention to their existence or in
mountainous regions by widening the zig
gag turns. The destructiveness of the
automobile increases in proportion to its
speed, but practically no effort is made
to limit speed beyond the confines os
towns and cottages. The speed evil is
correcting itself to some extent, owing to
the perils it presents to the occupants of
these vehicles.
''By virtue of the law of May 80, 1851,
vehicles OF all sorts may circulate in
France without restriction as to weight
Of load or width of tires. However, for
police purposes projects may establish GER
tain rules Thus, for example, factory
utilizing a public road for testing or
traffic purposes between given points, and
subjecting it to an intense strain. might
be required to take out some kind of a
license or otherwise make up its excessive
utilization of public property. 1t is a
recognized principle, however that in no
case shall agriculture be hampered by any
prescriptions in regard to highway trans
portation tending to interfere with the
harvesting, storing or marketing of crops. |
Without any regulation by law, tire
widths in this countr.- are greater than
in the United States. and under ordinary
circumstances have the effect of ironing
out the public roads rather than OF de-