The Richmond Virginian. (Richmond, Va.) 1910-1920, 1912-04-01

| recent number of the Scientific Amer
/ lean. says OF road building in this Sec
| ton Of the country:
! I'm the Southern and Southwest
| ern States especially there are large
! sections where sand and clay are read
! lily obtained. Clay and sand, when
mixed In proper proportions. make
a very good road surface for moderate
| trafic. The sand Is very hard and
F., admirably suited to resist abrasion.
| lacking only in adhesion or In bind
! ing power to form a firm road sur
! face. The binding value Is supplied
! by the clay. Only enough clay should
/, be added to GIL the voids. as its only
| purpose Is to act as binder. To
secure the best results the sand should
| be sharp and fairly coarse. while the
clay should possess n high binding
value and be OF fairly constant vol
! ume. that Is, II should vary but little
| In volume with different amounts of
| moisture. Some OF the so-called ball
clays," or sticky ciays, while very DIFF
! hcut to Incorporate uniformly with
| the sand. when properly mixed with
a suitable sand. form very good
road surface. The bail-ciays give
| much better results than loan or
shaking clays Such a road surface
| seems to be affected but little by
| moderate automobile traffic. Surfa ce
| treatments OF different kinds of oils
have been tried on the sand-clay
roads: but so far these applications
have been productive Of but little
good. The aterial seems to be too
| dense to permit even q quite iiouid
oil when applied hot to penetrate ap-
preciably into the surface.
| In tn. .veeter portion OF the agr,-
cultural Gi5.r.cts Of the South the cost
| Of this t.-m OF construction Is very
| low. ranging from about $399 to 5000
| per mile. This IL no more than some
| OF our States are finding thai II costs
annually TO maintain the macadam
raads subject to heavy automobile
traf1ic. In the South the automobile
Traffic IL rs yet comparatively light. so
that we have very little definite
| knowledge OF how the sand-cIay roads
are going to behave under heavy auto
fraffic. All we can say Is that so far,
| under moderate traffic. tho results OBJ
| tanned from this class OF construc-
| ton are most gratifying. The advan-
tages OF the sand-clay road have
| proved so great in the South that IL
would be advisable for many other
| rural regions to consider the posi-.
| biiity OF using this class Of construc-
| tion before adopting other and more
expensive methods
| Gravel suitable for building country
| roacs IL found In many localities
Some OF the ebert gravels. esnectallv
those of Alaba ma and Tennessee. pro
duce road notsinferior to the ordi-
| nary plain macadam. Many OF ,ne
glacial gravels. such as those Of In
diana. also make q satisfactory road
Tor moderate traffic. The r.rer or
creek EraVAla Avn
usually too rounded and devoid Of
binding material to be suitable for
ROAD building. except for use in the
foundation or In making concrete. etc
Gravel roads require considerable at
tenfion TO maintain them In proper
condition, and II Is not probable tina,
they will ever prove satisfactory ,,n.
der heavy automobile trafic. There
are, however. many rural sections
where the gravel road will answer
the needs OF the community. and they
snouiu De ADOPTED In preference 4.
more expensive types.
How They Get Power.
There still seem to be a good many
people who do not understand why
the six-cyiinder motor has SO Target,
displaced the four cylinder. and the
statesmen are busy explaining the r.a
! son these days In single sentence
| II II this: Fhe stx-cyfinder engine has
continuous torque," as the epxi-
neers call ft--that In, delivers power
continuously. instead OF applying II n,
intervals and In jerks One, two and
lour-cyiinder engines cannot possibly
have this advantage.
All gasoline motors deliver power
oy explosions. like shooting a bullet
a y,
piston. which turns the shaft connect.
ins. the engine with rear axle and so
makes the wheels 30 Unless somo-
thing were interposed to break up the
| shocks. the car would seem to be pro-
PEELED by series OF blows. There
fore. the ny wheel was introduced TO
maintain an even engine speed.
OBVIOUSLY the milder the force az
the explosions and the closer together
they come, the smaller and lighter
the fly wheel may be made So auto.
mobile inventors have worked fror,
the beginning In the direction of de-
velopins an engine In which the explo-
sio should be as nearly as possible
continuous and would not have to DO
30 fovceful
In the one-cylinder engine power Il
applied only cne-ouarier of the time.
II is AZ II q man riding q bicycle and
using only one foot pushed down On
the pedal and chen waited until ths
pedal went all the way round 1ni
came up a second time before he
pushed again. The effect Is q jcr2y
motion. You might expect that u
feur- cylinder engine could apply pow-
or steadily. but as inas.er OF fact II
IL necessary TO release the power -
the piston approaches the dead ceater
ut the end Of each stroke. No push
Is exerted on the piston during inc
last ffth OF the stroke. SO there Is still
A jerk when the power IL applied 40
the running 4ear.
Tho problem Of smooth running
engine that should apply its power
smoothly had reached this point when
]. Frank DuryeA--who built the ff-st
successful American automobile AMI
has been a pioneer In motor-car de-
velopment ever since--worked out the
ak cylinder motor. In the ''six'' the
idle pauses OF the fewer-cyIinder tybes
Of engine are completely eliminated.
The strokes not only meet, but they
overlap each other. Before the first
cylinder has stopped applying power
the second begins. and 70 on. In other
words. each revolution Of the engine
s----------.----
~ ~