Evening star., 1909-04-27
BIG CARS BURN ROADS
Speeded Like Lightning, They
Burn Up the MaCadam.
TESTS MADE THIS MORNING
Oiled Speedway Proves Better Than
Dust-Dry Conduit.
MANY CAMERAS IN ACTION
Distinguished Party Witnesses Of
fetal Experiments Under Direction
of Department Of Agriculture.
MANY CAMERAS IN ACTION

Autos going at from fifty-six to sixty
miles an hour flashed before a battery
Of cameras on the upper stretch of the
Conduit road this morning and tore up
the road surface for the good OF future
road-making. 1t was part of series of
tests that the Department of Agriculture
has been making to solve the dust prob
lem and determine the wear caused by
fast motor cars on macadam road sur
faces. 1t was hard on the road. to be
sure, but will ultimately help the cause
Of road-making.
After the tests on the Conduit road
which has only an ordinary macadam
surface, the cars all came back to Wash
ington and there was a similar series
of tests on the Speedway, where the sur
face has been oiled. The object, as re-
corded by the cameras, was to show that
the oiled surface, while it is not an alb
solute dust preventive, Is great pal
liative. the best thing. in fact, that has
been developed up to date.
Among Those Present We're
There was a small but distinguished
| party present at the tests. There was
Logan Waller Page. the director of the
| office OF public roads: l.. A. Coolidge,
Chairman Scott Of the House committee
on agriculture. Hennen Jennings, a prom
| 1nent highway engineer; Maj. Sylvester,
chief OF police: Quartermaster General
Alishire OF the War Department. Lieut.
Hanna, representing the office of public
buildings and grounds; ]. ID. Whelpley,
Emerson Hough, James Orme, Edward
Mclean. Samuel Luttrell, Fred Parsons,
I. B. Spense and several others.
A stretch OF about two miles Of the
Conduit road, above the Cabin John
bridge, had been guarded by policemen,
and no traffic was allowed over 1t during
the trials. This was necessary precau-
tlon, as the big cars at racing speed
were about as dangerous as meteorites or
woman carrying an umbrella.
Tests at High Speed.
All Of the runs were made at high
speed, as the object was to see what the
shearing effect Of the driving wheels
was on the road surface The Orme,
Mclean and Luttrell cars were all Of
the speedy type, and they were hurled
over the straight stretch of road at
railroad speed. Mr.. Whelpley acted as
| reached the first camera he fired a
pistol as a signal to snap the picture
and for the driver to throw out his
clutch and allow the next picture to be
taken with the car simply coasting un-
der its own momentum.
How the Tests Were Made.
The object Of the tests today was to
settle the still undecided question whether
the disruption Of the road surface is due
entirely to the speed Of the broad, soft
tires. or whether It comes chiefly from the
shearing effect that the driving wheels
Of the automobile exert on the road.
With this object in view the photogra-
piers who were making the records of
the tests were stationed on the road
twenty-five yards apart. There was in
very fast lense. and fifty yards farther
down the road a second camera of the
same sort. Midway between the two was
moving picture machine.
When the automobile reached the first
camera 1t was snapped. The driver then
threw out his clutch and the remaining
| two pictures were taken merely during
the acquired impetus Of the machine
The object of this was to see whether or
not the dust raised by the rear wheels
subsided at all after the power was shut
off
The whole trouble with the automobile
problem as affecting roads has been that
the macadam and telford roads were con-
Structed with a view to standing the wear
of the iron-shod wheels and iron-shod
hoofs. The theory was that the hard
hoofs and wheels would break up the
stones composing the surface of the roads
into fine dust, and this would be carried
by the rain into the interstices of the
road, forming practically a solid shell
over the surface and improving with con-
slant use This proved to be true enough
SO long as the roads were used by wagons
with hard tires travelling at comparative
ly slow speed. With the advent of the
automobile, however. the road was sub
jected to entirely different usage. The
soft tires did not crack the surface stone
and the suction from the wheels and the
body of the car raised the dust in Clouds
and this was carried away, leaving the
surface of the road exposed with the es-
sential binder missing. The resulting
trouble was more than in the annoyance
caused by the dust to residents along the
road, the depreciation of property and the
spelling of adjacent crops and foliage.
High Cost and the Remedy.
The cost for up-keep of the road be-
came prohibitive and almost impossible
at any price, owing to the rapid removal
of the surface dust on which highway en-
gineers depended for automatically re-
pairing the wear OH the surface.
The problem now confronting the road
Office is the production of asdustless road,
one which does not depend for it's life
on the dust produced by iron-wheel traf-
fic. 1t has been thought that this prob
lem would be solved in part by oling the
road, as has been done on the Washing
ton speedway and in many other parts
of the country and it has been attempted
by coating the road with asphalt and hot
coal tar. All of these methods are salts
factory in their way, but their cost is too
great for general application.
The road Office, while it is greatly trou-
bled in meeting the automobile problem,
does not wish for an instant to do away
with the automobile. 1t regards it as one
of the greatest instruments of civilization,
and wishes to evolve a road which will
withstand the new variety of wear and
tear as successfully as did the macadam
road for hundred years before.
Conduit Road Experiments.
Some months ago series of expert
ments were held on the Conduit road
by Logan Waller Page and DR. Alle1 ton
S. Cushman. respectively director and
assistant director of the office of public
roads of the United States Department
of Agriculture, for the purpose of study
ing the phenomenon of dust removal by