DUST PREVENTION AND EOAD PRESERVATION, 1916. 71 
YOUNGSTOWN, OHIO, 1909. 
SLAG, SLAG AND LIME, SLAG AND WASTE SULPHITE LIQUOR PREPARATION, AND SLAG 
AND TAR. 
The original report describing these experiments was published in 
Office of Public Roads Circular No. 92, and subsequent reports of 
annual inspections in Circulars Nos. 94, 98, and 99, and in Bulletins 
Nos. 105, 257, and 407, U. S. Department of Agriculture. The fol- 
lowing report describes the condition of the various experiments on 
December 4, 1916, and furnishes a brief resume of previous reports. 
The experiments are discussed in the order of their section numbers, 
beginning at Mahoning Avenue. 
Section No. 1 , blast-furnace slag — The condition of this section was 
unchanged materially since the inspection in December, 1915, except 
that the middle of the road was no longer pulverized, and pronounced 
depressions about 2 inches deep have developed in the wheel tracks 
at about 150 feet and 175 feet from the north end. A hole dug about 
200 feet from the north end of the section showed the depth of slag 
to be about 8 inches. A laboratory examination of a sample of this 
slag showed (1) that the slag particles were carbonated on the surface 
and (2) a cementing value of 55. 
Section No. 2, blast-furnace slag and lime — The south one-half of 
this section showed two wide, shallow ruts, with a slight accumula- 
tion of fine loose material along both edges of the road, and over this 
part of the section the crown of the surface had disappeared almost 
entirely. The remainder of the section had not changed materially 
in appearance since the inspection of December, 1915, except that 
the ruts had become slightly more pronounced and a few of the 
foundation stones were showing in the surface. Holes dug at 125 
feet from the north end and 30 feet from the south end showed the 
depth of slag to be 6 1 inches. A sample of this slag showed (1) that 
the slag particles were carbonated on the surface and (2) a cement- 
ing value of 115. 
Section No. 3, blast-furnace slag and waste sulphite liquor prepara- 
tion — The north end of this section, for a distance of 100 feet, was 
resurfaced with slag sand in the fall of 1916. The next 100 feet 
showed a rather loose surface with two broad, shallow ruts, though 
the depression along the center of the road noted in December, 1915, 
had almost disappeared. The remainder of the section (300 feet) 
was worn uniformly and in good shape, except for depressions in the 
ruts near the middle of the section, which cover an area of about 
2 square yards, and the west edge of the road had been partially 
destroyed to a width of about 1 foot for a distance of about 100 feet 
from the south end. The latter damage was caused by failure to 
maintain the shoulders in proper shape. The south end of the sec- 
