1915. 57 
At the time of the inspection made on February 25, 1916, the con- 
dition was substantially as follows : 
Section 1, which was not re-treated during the past season, appeared 
in no need of re-treatment. 
Section 2 had become rough and uneven, owing both to settlement 
under traffic in extremely wet weather and to disintegration of the 
surface. One large hole had developed on the south side at a point 
where traffic entering from Fourteenth Street fails to turn closely 
enough to the north corner and in consequence shears away the south 
edge for several feet. This section has also a number of potholes and 
spots where the mat was entirely worn away. Extensive repairs will 
be necessary as soon as the weather permits. 
Section 3 suffered as usual on account of seepage from the terrace 
that lies along the south side of the section. An effort was made to 
drain this section and a small part of section 2, but sufficient funds 
were not available to complete the work. 
Section 4 has remained in excellent condition. Only one small 
area at the south end has required any attention. The break at this 
point was due to the impact of traffic passing from the asphalt drive- 
way to the surface treatment. 
SUPPLEMENTARY REPORT OF EXPERIMENTS AT CHEVY CHASE, MD., 
1912. 
BITUMINOUS CONCRETE, CEMENT CONCRETE, OIL-CEMENT CONCRETE, VITRIFIED 
BRICK, BITUMINOUS SURFACE TREATMENTS ON CONCRETE. 
The original report of these experiments was begun in Circular No. 
99 of the Office of Public Roads and completed in U. S. Department 
of Agriculture Bulletin No. 105. Report of inspection made on 
March 14, 1915, was published in Department Bulletin No. 257. The 
following report covers the condition of experiments on February 
28, 1916. 
Experiment No. 1. — Bituminous Concrete, Topeka Specification. 
The general appearance of the experiment is the same as at the last 
inspection. Imperfections then noted still exist in addition to those 
noted here. There is one bad break at the north side of the turn into 
Bradley Lane. Both surface and concrete gutter are broken and 
indicate some unusual blow. The depression noticed about midway of 
the section near the curb has increased in size and depth. A second 
cup-hole 200 feet north of Bradley Lane, near the east side of the 
road, and a third one, 60 feet from the north end of the limestone 
section, were noted. In the last 60 feet of this section, 10 or 12 slight 
imperfections appear. On the trap section a noticeably increasing 
waviness occurs along the gutter for a width of 2 to 2 i feet. 
