DUST PEEVENTION AND EOAD PEESEBVATION, 1915. 69 



Section No. 4. — Blast-Furnace Slag and Repined Ooke-Oven Tar. 



The greater portion of this section was constructed over a deep 

 fill and, as noted in previous inspection reports, initial failure was 

 due to unequal settlement. The surface over the fiU and the short 

 stretch to the north has disintegrated and numerous holes and depres- 

 sions have formed, ranging from a square foot to a square yard in 

 area. The south 50 feet of the section, which has not suffered from 

 settlement, remains practically intact and presents a smooth, true 

 surface. The wearing surface was cut through with great difficulty 

 and it was necessary to use a sharp pick in order to remove a small 

 section for examination. 



Section No. 5. — Blast-Furnaob Slag. 



As noted in former inspection reports, this section is lower at its 

 junction with section No. 4 by about 1^ inches. The ruts in the 

 portion lying in the damp cut remain. The south one-third of the 

 section, which at the last inspection was in very satisfactory condi- 

 tion, has developed two depressions at 165 feet and 135 feet, respec- 

 tively, from the south end. Both were about 2J inches in depth 

 and showed signs of raveling. 



Section No. 6. — Blast-Furnace Slag. 



This section has not changed materially during the past year. The 

 ruts are wide and more pronounced than in the preceding sections, 

 but there is less loose pulverized material in the middle of the road. 

 There are two rather deep depressions in the traveled way near the 

 middle of the section and three long, deep ones in the east rut in the 

 north 100 feet of the section. However, there was no evidence of 

 raveling in any of these depressions. 



Section No. 7. — Blast-Furnace and Open-Hearth Slag. 



The condition of this section has not changed appreciably in the 

 past 12 months. The surface as a whole is firm and well bound and 

 noticeably harder than any of the other sections, except that portion 

 of No. 4 which stiU remains intact. 



Several years ago the fill near the south end of the section settled 

 irregularly and a deep hole was formed. This has not been repaired 

 and continues to be a menace to traffic. 



SUPPLEMENTARY REPORT OF EXPERIMENTS AT GARDEN CITY, BUCK- 

 UN, FORD, AND DODGE CITY, KANS., 1908. 



SAND-CLAY. 



The original report of these experiments is contained in circular 

 No. 90, and reports of subsequent annual inspections arc published 

 in Circulars Nos. 92, 94, 98, and 99, Office of Public Roads, and in 



