319 
PARK AND CEMETERY. 
ity as that applied in 1907, at a cost of 
about iAz cents per square yard. The 
oil proved to be of an entirely different 
character, and as nearly as could be 
determined contained paraffin to such an 
extent that there was little binding qual- 
ity. At each rain the oil emulsified and 
the surface of the road would grind up 
into a thick, black, greasy mud, leaving 
the road in a deplorable condition. The 
covering of the oil with sand, thus 
avoiding the necessity of closing the 
streets, was tried, but the sand with the 
poor oil, tended to disintegrate the sur- 
face so that it scaled off in large 
patches. 
This year we have treated several 
miles of streets with a 65 per cent 
asphaltum oil. The same preparation of 
the roads was made as before. The oil 
was applied in a similar manner, after 
which stone screenings were spread on 
to a depth of about one-half an inch 
and thoroughly rolled. The first re- 
sul,ts promised to equal the experiment 
of 1907. The roads were hard and 
smooth within a few days after being 
treated, but at the first rain they were 
in the same condition as in 1908, the 
caqse, I believe, being solely in the 
quality of the oil used, and not in the 
method tried. Despite these unsatisfac- 
tory results, there has been some good 
derived from the use of these oils. 
While the road was in had condition 
during rainy periods, it dried out 
and became hard and smooth and nearly 
dustless in a few hours after a rain. 
The use of a heavy grade of asphaltum 
oil as a binder in place of sand or clay 
has given fair results. On an old road 
a layer of 4 inches' of IJ^ inch stone was 
spread and rolled t6 an even surface. 
The oil was heated to 150 deg. F., and 
then applied to the 1>4 inch stone. One 
and eight-tenths gallons was used to the 
square yard at a cost of 10^^ cents. 
Stone screenings were then spread over 
the road and thoroughly rolled. Wher- 
ever the rolling brought the oil to the 
surface, screenings were added to take 
up the surplus oil. One objection which 
I have noticed in this road, which may 
develop into a serious one, is a ten- 
dency for the road to spread and creep 
under traffic. 
I consider it essential in surface treat- 
ment that the road be allowed to stand 
from four to six hours after putting on 
a covering of sand or screenings. The 
oil then has a chance to penetrate the 
hard surface of the road, so that when 
sand or screenings are added and rolled 
in, there is formed a bond with the old 
surface which is not obtainable other- 
wise. The percenta.ge of asphaltic base 
in the oil to be used depends in a great 
measure on the road to be treated, and 
the traffic conditions also enter largely 
into determining this question. 
I am of the opinion that the surface 
treatment with an oil having the proper 
quality and quantity of asphalt base will 
secure to us a resistant and resilient 
wearing surface which wdll withstand 
the traffic in residential suburban cities. 
The cost of this treatment would not 
exceed 5 cents per square yard per year. 
The elimination of the dust nuisance 
would be practically accomplished. 
While I believe it is possible to suc- 
cessfully solve these questions by the 
method proposed, yet I am not indiffer- 
ent to the uncertainty of success due to 
the possibility that the oils will not be of 
the same quality from year to year. 
The solution, therefore, of this mat- 
ter seems to depend more on the qual- 
ity of the oil used than in the method of 
application.. If we are to continue the 
use of asphaltum oils as the means to 
preserve and render dustless telford and 
macadam roads, careful attention and 
study must be made to determine just 
the quality of oil that will give us these 
results, and specifications should be so 
drawn as to insure securing the oil of 
the required quality. 
DISCUSSION. 
The President: I have been working- hard 
on this ciuestion of bituminous binders, and 
have obtained some rather peculiar results. 
The results are such that they can hardly 
be callexl satisfactory. i have tried surface 
oiling with oils of dilferent weights, 25 per 
cent and 50 per cent, and with asphaltum 
oils of SO or 0 0 per cent. The surface 
SPREADING SCREENINGS OVER OIL AND ROLLING. 
