PARK AND CEMET ERY. 
181 
to fourteen cents per square yard, 
while if the surface is specially pre- 
pared, or new stone used, the cost of 
a macadam surface treated with 
“tarvia” or oil may vary from twenty 
to fifty cents per square yard. Very 
few macadam surfaces that have been 
used for any length of time are in a 
condition to receive this sort of treat- 
ment without some re-dressing or 
new stone, so the minimum figure 
given above will often be very great- 
ly exceeded. 
The method of treatment referred 
to is what we call the penetration 
method, which generally applies as 
the bitumen used is heavy enough to 
act as a binder between the particles 
of stone. It must be heated when 
applied, and to be effective it must 
penetrate a certain depth. The meth- 
od of application is as follows: The 
bitumen, either oil or tar, is heated 
in portable wagon tanks (after being 
thoroughly mixed in a large tank) to 
at least 200 degrees Fahrenheit and 
then spread upon the road surface un- 
der steam pressure of from twenty 
to fifty pounds through a hose with 
a spraying nozzle, handled by a com- 
petent man, making sure it is applied 
evenly. Immediately after the ap- 
plication and before it has time to 
set firm, a thin layer of clean stone, 
not over one-half inch in thickness 
should be used, then rolled, but not 
too much, as many a good road has 
been permanently ruined by too much 
rolling after the bitumen has been 
applied. 
To apply bitumen and get good re- 
sults, the stone must be dry and the 
weather warm. If applied in cold 
weather it will begin to crack and 
break in a few months, and if the 
cracks are numerous the only repair 
that can be successfully made is to 
spike up the whole surface, harrow it 
to bring the coarse stone to the top, 
or add a layer of new stone, roll down 
well and then put on a new applica- 
tion of bitumen. The time of the 
year when the greatest damage is 
done to driveways treated by the sur- 
face or penetrative method is the 
winter or spring when the frost and 
excessive moisture have left the mac- 
adam in a somewhat loosened and 
weakened condition and when the 
bitumen is more or less brittle from 
the cold. When in this state a road 
surface apparently in good condi- 
tion will sometimes go to pieces bad- 
ly in a few days. Another thing to 
be considered is the character of the 
vehicles using the roadway. Plain 
rubber tires are comparatively harm- 
less on any sort of bituminous sur- 
faced roadway where the particles are 
sufficiently bound together to pre- 
vent their being loosened, and where 
the protective coating of bitumen is 
not broken through. But the grind- 
ing and pounding of iron-tired traffic 
has a much more serious effect 
where the layer of bitumen is com- 
paratively thin, especially during the 
season when it is brittle and easily 
ground off by heavy traffic. 
We find much more evidence of 
this in our freight yards than on the 
driveways to our passenger stations. 
As the use of a driveway increases 
and as the grade and traffic passing 
over it improves, just in proportion 
does the objection increase to the 
repeated use of so disagreeable a sub- 
stance as road oil. Like many other 
crude things of life it is tolerated 
when nothing better is known or 
nothing better can be afforded. We 
find it much cheaper to buy the bitu- 
men from a large manufacturer, 
mixed in proportion as desired, than 
On September 11 and 12, 1911, there 
was held at Yellowstone National 
Park a conference of national park 
superintendents, officials of the De- 
partment of the Interior having super- 
vision over national park affairs, rep- 
resentatives of other branches of the 
Federal Government whose work 
brings them into relation with the 
national parks, concessioners in the 
parks, and representatives of the rail- 
roads directly interested in the trans- 
portation of tourists to the parks. 
This conference served as a medium 
for the exchange of ideas and sug- 
gestions for the betterment of the 
national parks and has been produc- 
tive of much improvement in their 
administration. 
The Secretary of the Interior has 
decided to hold a second conference 
at the Yosemite National Park, Cali- 
fornia, on October 14. This second 
conference will be along the same 
general lines as the Yellowstone con- 
ference of last year, including dis- 
cussion of road building, general ad- 
ministration, sanitation, et cetera, and 
particular attention will be given to 
the question of the admission of auto- 
mobiles to the parks from which they 
to do our own mixing, as we only 
use a small quantity at one place. 
Cities that use large quantities will 
find it cheaper to buy the material 
in a crude state and mix with a ma- 
chine or by hand in a large vessel 
made for the purpose. No skill 
is required to mix bitumen, but one 
should be sure and get the proper 
amounts of tar, asphalt and oil. 
I will say in conclusion that we al- 
most invariably use a tandem roller 
of not over ten tons. We like it bet- 
ter than the Springfield roller, as the 
ground covered by the tandem is 
much greater than the Springfield — 
therefore you can roll fresh bitumen 
much quicker and complete the road 
before it has time to harden — leaving 
a smooth surface and no marks. Af- 
ter we complete a driveway we do 
not allow any vehicles of any kind 
on it for from eighteen to twenty- 
four hours. This gives it ample time 
to harden so the wheels will not 
make ruts in it, thereby spoiling the 
surface of the road. 
are now barred. The only persons 
going from Washington are Mr. 
Clement S. Ucker, chief clerk of the 
Department, who will act as secre- 
tary of the conference, and Mr. 
Frank Bond, chief clerk of the Gen- 
eral Land Office, who has charge of 
national monuments under the juris- 
diction of the Department of the In- 
terior. 
The following National Park super- 
intendents will attend: 
W. F. Arant, Crater Lake, Klamath 
Falls, Oregon. 
R. H. Chapman, Glacier, Belton, Mon- 
tana. 
S. E. Shoemaker, Mesa Verde, Mances, 
Colorado. 
E. S. Hall, Mt. Rainier, Ashford, Wash. 
W. J. French, Platt, Surphur, Okla. 
Capt. W. M. Whitman, Sequoia and 
General Grant, Three Rivers, Cal. 
C. M. Ziebach, Sully’s Hill, Fort Totten, 
North Dakota. 
W. M. Boland, Wind Cave, Hot Springs, 
S. D. 
Lt.-Col. L. M. Brett, Yellowstone, Yel- 
lowstone P., Wyoming. 
Maj. W. W. Forsyth, Yosemite, Yo- 
semite, Cal. 
H. H. Myers, superintendent. Hot 
Springs Reservation, Hot Springs, Ark. 
H. M. Hallock, medical director. Hot 
Springs Rerservation, Hot Springs, Ark. 
Wichita, Kas., may have five new 
parks, at a cost of some $35,000 for 
the land, if the efforts of the Civic 
Clubs of the city are successful. Op- 
tions on sites have been secured. 
There has been no official recog- 
;'-A l A 
PARK NEWS. 
fLfclUi 
THE NATIONAL PARK CONFERENCE 
