PARK AND CEMETERY. 
430 
our rule is to dig down and find it. 
Over in Kansas they found and con- 
tracted for a heavy oil at eighty cents 
])er barrel of forty-two gallons, f. o. b. 
Kansas City, and this is the oil we 
are still using. It is not the crude 
oil as it comes from the wells, as our 
crude oil has but little value as road 
oil. It is a residuum from which tire 
distillates naphtha and kerosene have 
been removed and has a paraffine 
base. 
In Los Angeles they have a na- 
tive oil with asphaltic base which they 
use direct from the wells. An oil 
with asphaltic base is a better road 
oil than one with a paraffine base. Our 
oil has a specific gravity of 20 to 21 
Baume. 
Oils and other substances which are 
lighter than water are referred to 
readings on the Baume hydrometer. 
This is an instrument used in tech- 
nical work to obtain relative specific 
gravity. Distilled water is used as a 
standard, and its reading is ten on 
the hydrometer. The heavier the oil 
is, the closer it approximates to ten, 
all readings being kept at a constant 
temperature, 15 deg. C. or 60 deg. F. 
Our oils were at first all tested by 
the city chemist, but as his reports 
were of little value, owing to scien- 
tific statements contained, we finally 
purchased a hydrometer and make our 
own tests for specific gravity. 
For the advantageous handling of 
oil we put in a switch track on the 
Belt Railway and built two steel re- 
ceiving tanks of 8,000 gallons capacity 
each* at a cost of $715. These tanks 
were built at such an elevation as 
would permit of unloading from tank 
cars into them by gravity, thence into 
sprinkling carts by same method. 
In 1907, beginning in May, our en- 
tire system of macadam roads was 
SPRINKLING WAGON 
With Oiling Attachment 
treated with an application of oil, and 
during that year most of them were 
given two applications. We used 
thirty-three cars of oil and the cost, 
including oil and labor, w'as $10,- 
671.11, or about two-thirds as much 
as the old method of sprinkling with 
water. The results were in every 
way more satisfactory. It gave us 
dustless roads, impervious to water, 
and held in place the finer material 
as cover to the macadam, which, un- 
der the sprinkling with w'ater prac- 
tice, was torn loose by automobiles 
and washed into the gutters by rain 
and sprinkling, or blown away by the 
wind or dust. 
No W'ater from rain or snow pene- 
trates the oiled surface and the road 
is dry as soon as the rain ceases or 
the snow melts. The freezing and 
thaw'ing of the winter and spring 
breaks the surface but little. 
The first application of oil to a 
road is the most expensive. More 
care and work are required to pre- 
pare the street, and more oil is used. 
In the first application, the oil pene- 
trates further than in subsequent 
ones. We figure the cost of the first 
treatment at one and one-half cents 
per square yard, against one cent par 
yard for later applications. One gal- 
lon of oil covers from three to four 
square yards of surface. 
Before applying, the road should be 
swept as clean as possible to insure 
better contact and penetration and to 
lessen its picking up. For this we 
use the ordinary rotary street broom, 
although it can be done as well with 
the hand push broom. The sweepings 
are left along the’ edge of the gutter 
to protect the cement work from the 
oil. 
Oiling a road is dirty work, and 
care must be taken to protect the 
crossing to the public, keep the work- 
men from tracking up the cement 
work, and to preserve and restore the 
street as quickly as possible. To do 
this, the best practice is to barricade 
one-half of the street in the block to 
be oiled, before any oil is spread. As 
soon as the half block is oiled and 
broomed until there are no bare spots 
or pools of oil, the -sweepings along 
the gutter, together with sufificient 
limestone screenings to form an ab- 
sorbent, should be flirted over the 
freshly oiled surface. It is good prac- 
tice to follow this dressing with a 
light road roller, especially if the 
travel over- the road is light. Where 
there is much travel, the rolling is not 
so essential, and wo do not always do 
it, hut open the street at once. The 
APPLYING THE OIL. 
BROOMING AFTER THE WAGON TO 
PREVENT POOLS. 
Other half of the street may then be 
treated immediately in the same man- 
ner, or left for some more convenient 
time. 
The pavement should of course be 
dry, as oil and water just won’t mix, 
and the hotter the pavement, the 
better. In cool weather we find it 
necessary to heat the oil so it will 
flow freely. For this purpose we have 
each of our receiving tanks piped 
with l4-inch steam pipe from a four 
horse-power boiler, purchased for 
that purpose at a cost of $67.50. This 
is set up close to the tanks and en- 
closed in a knock-down boiler house. 
When, as it often happens, the oil 
stands in the sprinkling cart over 
night and is too heavy to flow well, 
we heat it in the cart with a steam 
hose from a road roller. My advice 
would be, always heat the oil; it pen- 
etrates better, picks up less and covers 
more. 
For distributing the oil on the road, 
we use the ordinary street sprinkler, 
discharging the oil into a perforated 
tin trough under the outlet valves, 
which is hung parallel to the wagon 
axle. This trough is about seven feet 
long, six inches wide and six inches 
deep. The size of the perforations 
depends on the kind of oil used. One- 
quarter inch holes about one and one- 
half inches apart serve for sucli oil 
