The record-union., 1893-07-26
Some Road Facts.
Santa Cruz Sentinel.

A New York journal has employed
correspondent i'll England to collect facts
and figures in regard TO the construction
OF macadamized and other scientifically
made roads i'll the different countries of
Europe. In recent letter the CORE
spondent sends some facts which will Q
of special interest just now when road
building is prominent in the public
mind. We quote some OF these state
mens as a contribution TO information
which will be useful to the road conven-
ton that is to be held in Sacramento in
September. The writer referred to says:
1.-The thickness OF a road made alto
gether Of broken stone depends on the
traffic. On a good, Well-drained soil a
thickness Of six inches makes an excel
lent road for ordinary traffic, and Mac
adams opinion that ten inches OF well
consolidated material was sufficient to
carry the heaviest traffic on any sub
stratus, if properly drained, has been
proved by engineers generally to be cor
rect. In a new road q loss of thickness
to the extent of one-haIf has TO he al
lowed for during consolidation. a pitched
foundation like that used by Tel!ord
is found to be always desirable for
road that is subject to heavy traffic.
1t consists Of Hat stones carefully set
on edge III courses across the road with
the broadcast edges downward. The up
per euGOS SlOulu HOL GACGGu lOuI IDCutS
i'll breadth. The thickness of the pitch
ing is generally six or seven inches; i
should not be less than four For heavy
traffic the best materials are traps, basalts,
greensboro and syenite; quartz ore grits
and chertz saudstoneS are also excellent
materials, While for moderate traffic the
harder limestOnes are sufficiently durable
and make tie smootheSt and pleasantest
roads. Limestones have the advantage
hot n 1IGh "a vi NIX
which binds the stone together and en-
ables it to wear better than harder ma
terial that does not bind. AS regards
wear, it is seldom found 10 exceed half an
inch, or, on the most trequented roads Of
England and France, one inch Of cOnsoli-
dated surface per year. In France, 100
cubic yards OF good material per mile per
year are considered as the average con-
sumption for traffic Of 100 horses a day.
AS regards repairs, the usual method
throughout Europe where macadamiZed
roads prevail, is to add new material
to their coats and small patches year by
year,
AS the above facts are based upon
actual experience they are valuable as
guides. The same general results as to
material, methods of construction, an
nual wear, and modes of repair which
have followed in Europe may OF course
De relied upon 10 follow similar treat
ment i'll this country 1t Will be seen
that the harder limestones have made
their way to favor in Europe as material
which is sufficiently durable and makes
the smoothest and pIeasantest roads,"
and Which has The advantage of furnish
ing "mortar-like detritus which binds
the stone together and enables it to wear
better than harder material that does
not bind" 1t is gratifying to know that
material which is so abundant in Santa
Cruz County has the approval of scien-
titic road builders in the old world. The
writer also says that in towns and
populous districts of Europe, ''btu-
minous" concrete is much used as an APP
proved material.
Some figures are given relative to the
cost OF roads in different countries of
Europe, but as no figures are given rela-
tive to the width of the roadbed no intel
Hgent comparison can be drawn with
reference to the probable cost here. The
average cost of making new Government
roads in Bavaria, including the amount
paid for right of way, is given as about
$3.50 per English mile.