The sun. [volume] (New York [N.Y.]) 1833-1916, 1893-07-23
ROADS OF GREAT BRITAIN.
WHAT MhOkDAM DID FOR THEM-soMB
NOVEL DhYICks AND ELPERIMkETS

TMxCxDhM DID FOR THEM-soMB
NOVEL DkpIcks AND APPROPRIATENESS
Street P.ve-,-nt. or Lousor, Liverpool,
Dubiir, Belfast. Glasgow, Edinsursh-
Country Highways In the United Rinsdom.
In 1916 Mr.. John Loudon Macadem began
his system Of putting broken stone upon .
| road which shall unite By it's own angles 80 as to
form solid. hard surface. IL must remain in
the situation in which It 10 placed. whereas
| gravel must be In constant motion" The
| choice OF angular stones. so as to form Q sort
| Of mosaic or interlooking system" the care
| to secure proper foundations. and thorough
| rolling. are the three great elements in modern
| British road making. Macadam. In his testi-
| mony before House OF Commons committee.
| held that a road should be as fat as possible.
| with only Just enough slope to allow the water
| TO escape. Carriages need. he said. to stand
upright. and II you make the road too convex
| they will go for the centre. and there the wear
| will be greatest, so that the water will soon
| collect there. His own practice was to make
| roads only about three inches higher in tho
| centre than on the sides. and to make all parts
| Of the road equally hard.
He often built road In what he called
| three es"-that is. with q layer OF broken
stone about four inches thick. worked until it
was set, then q second then third. Whin-
stone. used much in tho north OF England and
in Scotland. was apparently his favorite ma
terial. as the most durable but he accepted as
adequate flint in Essex and Sussex: limestone
In the west which consolidates quickly and
makes smooth road. but not the most lasting:
,the hard pebbles OF Shropshire. and 30
In maintenance and repair the difference boz
tween q town and country m cadamized road
is, ns Consul Daniels expresses It, that tho
former il hacked over. spread with nough
broken whinstone to raise 1t to 1t proper
level AMI cumber. and rolled with q heavy
roller O loamy gravel being used as binding
material for the interstioes. whereas on coun-
try roads the old surface is not hacked over.
nor the new material rolled. but lett to be CON-
solidated by travel
Macadam substituted for the old high
curved road. consisting Of about four feet Of
large stones and other material. an almost
fat and smooth road about q foot thick. He
chose wet weather for repairs. He introduced
the plan Of loosening the hardened surface
with pick before putting In his first layer Of
broken stone. He had his stonebreakers sit
down to their work. In short. he introduced
many new details. which are now familiar.
And his plan Of using old material enabled his
roads to be built and repaired with unpreoe-
dented economy. In time machine broken
stones came in. His system was presented to
Parliament in 1919. but not until 1884 was II
supplemented by NJ Polonceau's introduction
OF the steam roller. The elder Macadam lived
to see great changes wrought By his system.
Tho streets Of London have many varieties
of pavement In Kensington there Is great
deal Of wood pavement which Is laid on con-
CRETE and usually consists Of creosoted deal
blocks. Most Of the wood Is six inches deep.
but OF late years flve-inoh blocks have been
sub stituted. and Engineer Weaver. in his re-
port to Mr.. New. thinks that i've inches
will be the usual depth hereafter. in
order to effect q saving in cost, and that
lve-inoh wood p aving will last ten years.
Surveyor Harvard of Greenwich. however.
puts the life OF wood cube paving at four to
five years. that Of asphalt at fifteen to twenty.
II 1t could be left undisturbed. and that Of
granite cubes at twenty-one years. most
set OF comparisons between wood,
asphalt. and granite pavements Is made By
Engineer Haywood. From Q series OF expert
ments he reached those conclusions:
That asphalt was most slippery when merely damp
and safest when perfectly dry; that horse might DO
expected to travel the asphalt without accident
nearly twice the distance when the pavement dry
that It could do when damp and that the difference
between tho safety OF asphalt whom wet and dry
not considerable BEL. 20. II ~
That granite slippsry whom dry. and safsss
whom wet: that horse might DO expected to travel
granite without accident nearly seven times the dig
tanoe whom the pavement WAS wet than whom dry.
and that the granite was about twice a. safe when
m erely damp 40 when dry.
That wood was most slippery when damp and safest
when dry; that horse might DO expected 80 travel on
the wood moro than three times the distance when
the pavement was dry than whom damp. and that the
wo cd than twice as safe when a. when
damp
Here. however. It Is necessary to say that
very different results are shown between
asphalts Of different kinds: and the same. In
[act 10 true OF wood Oavements.
=, In BIRMINGHAM careful investigation BY
bloeks had been placed on a bed Of loose sand
q q gravel Is T. often the case in the United
In '1 O. sxay
he same rule Is followed; and the paving In the
inc s11' ade Of By srsf dss
rom North Wales or other approved ,Quarries.
tan shs asS f the s
lined and stone bedd Cd. that attract the not.es
ia S. S Shsh the nasAdans
very durable It being. in fact. SO hard as some
ike the Niohoiso Hv and %aeSdaa:
on Tie o Eassnd ana
Wales: as the frequent rainialls make the soil
,fs they lit rem sos
Out OF $50 miles Of streets In Belfast about
IS Mh soa % xt
late brickiayers received Is cents per hour:
IA PAYERS. II to 1T The best
~ contract. The sets are laid on q concrete
led composed Of four parts broken stone. two
PARTS broken brick. two parts gravel. and ono
BART best Portland cement. This concrete
nay be y. 8. or II inches thick. according to
he traffic and the nature OF the ground. All
he material must be clean. For macadamiz-
ng whinstone is mostly used
The roads Of Scotland are often very good
indeed and there Is admirable stone for them
n abundance. The Scotch havo excellent
;ranites. the Guernsey being called the most
urable. The cost Of an ordinary road. eighteen
Get wide, Mr.. Held puts at about $1,000
nile. The first stop In constructing u new
lle on each side OF the roadbed. the tile asa
ule being laid three feet below the surface.
nd varying in size from 3 to Is inches or more.
he cost Of laying being 8 to 4 cents per yard
Mess over inches. The mode OF constructing