42 BULLETIN 257, U. S. DEPARTMENT OF AGRICULTURE. 



SUPPLEMENTARY REPORT OF EXPERIMENTS MADE AT NEWTON, 



MASS., 1908. 



ASPHALTIC PREPARATIONS, TAR PREPARATIONS, RESIDUAL OIL, AND MOLASSES- 

 OIL-LIME. 



The original report of these experiments was published in Circu- 

 lar No. 90, and reports of annual inspections were given in Circulars 

 Nos. 92, 94, 98, and 99, Office of Public Roads, and in U. S. Depart- 

 ment of Agriculture Bulletin No. 105. No repairs have been made 

 during the past year, and the following report covers an inspection 

 made on October 5, 1914. 

 ! 

 Experiments Nos. 1, 2, 3, 4, 5, 6, and 7 (Asphaltic Preparation — Mixing Method). 



The first four of these sections, which have been reported as 

 badly worn and hi need of resurfacing, have continued to deteriorate 

 so that almost none of the original surfacing shows. All of these 

 sections are badly rutted and full of holes, with the exception of one 

 piece of road, about 30 feet in length, at or near the beginning of 

 experiment No. 3. This is in practically perfect condition for the 

 entire width of the roadway. 



Experiment No. 5 in its entirety is now in about the same condition 

 as the first four experiments and is in need of resurfacing. 



Experiment No. 6 continues to be in very good condition. 



Experiment No. 7 contains about 20 places varying from depres- 

 sions to holes, with about 14 holes which vary from 6 inches in diame- 

 ter to an area of 4 square feet. It is evidently deteriorating rapidly 

 through the "cupping" action. The three holes reported in Circular 

 No. 99 as needing patching now show only traces of the binder, but 

 there is a good mechanical bond in the foundation stone. 



! Experiment No. 8 (Residual Petroleum — Mixing Method). 



■/ The eight small holes which were reported in U. S. Department of 

 Agriculture Bulletin No. 105 have developed so that they' vary from 

 6 inches in diameter to an area of 2 square feet. On this section there 

 are indications of rutting and raveling near each quarter-point. The 

 section should be patched and surface-treated if further deterioration 

 is to be prevented, otherwise it seems probable that an inspection next 

 year will show that it will need resurfacing. At the westerly side of 

 Langdon Street there is evidence of a trench having been dug across 

 the entire roadway in order to supply a fire hydrant, and the old 

 material has been thrown back without any attempt at surface 

 patching. 



Experiments Nos. 9 and 10 (Refined Water-gas Tar — Mixing Method). 



These experiments appeared to be in practically as perfect condition 

 as reported in U. S. Department of Agriculture Bulletin No. 105. 



