DUST PREVENTION AND ROAD PRESERVATION, 1914. 37 



very poor condition; the seal coat is gone, and quite a number of 

 potholes have been formed, especially on the south side. 



SUPPLEMENTARY REPORT OF EXPERIMENTS MADE AT NEW YORK, 

 N. Y., AND RIDGEWOOD, N. J., 1910. 



OIL-CEMENT CONCRETE. 



The original report of these experiments was published in Circular 

 No. 94, and the reports of annual inspections appeared in Circulars 

 Nos. 98 and 99, Office of Public Roads, and in U. S. Department of 

 Agriculture Bulletin No. 105. The following report covers an in- 

 spection made in October, 1914. 



Experiments at New York, N. Y. 



This roadway was torn out in its entirety the wee"k of September 

 27, 1914. The general condition of the surface of the road had 

 gradually deteriorated from the condition shown by the inspection 

 reported in December, 1913, and it was decided by the road main- 

 tenance department of the Borough of Richmond that the entire 

 roadway should be torn up and a new one laid. It has therefore 

 been replaced by bituminous concrete on a cement-concrete founda- 

 tion. 



Experiments at Ridgewood, N. J. 



Experiment No. 1. — The oil-cement concrete floor of the bridge over 

 Saddle River was covered with a bituminous surfacing, as reported 

 in the inspection made in December, 1913. The bituminous-macadam 

 surfacing is in first-class condition, and the oil-cement concrete is not 

 exposed. 



Experiment No. 2. — The oil-cement concrete floor of the bridge 

 over the Hohokus River is apparently in similar condition to that 

 reported in December, 1913, excepting for the fact that it is a little 

 more worn. The surface is even and smooth and has a rather flat 

 cross section. The wear on this bridge floor still continues in the 

 center of the roadway, since the sides for a width of from 3 to 4 feet 

 from each edge are protected by dirt and leaves. In the center the 

 large stones of the aggregate show on the surface, and at the ends of the 

 bridge the edges of the concrete are rounded off to meet the surface 

 of the adjoining macadam road. 



SUPPLEMENTARY REPORT OF EXPERIMENT MADE AT BOISE, IDAHO, 



1910. 



OIL-GRAVEL MACADAM. 



The origins] reporl of this experiment was published in Circular 

 No. 94, and reports of annual inspections were given in Circulars 

 No ,98 and 99, Office of Public Roads, and in U. S. Department of 

 Agriculture Bulletin No. L05. The following report covers an inspec- 

 tion made on January 2, L9 15: 



