484 EXPERIMENT STA.TION RECORD. 



Twenty-first annual report of the commissioner of public roads for tlie 

 year ended October 31, 1914, E. A. Ste\t.ns (Ann. Rpt. Comr. Pub. Roads 

 [N. J.], 21 {19 H), pp. 107, pis. 6). — This report describes and states the cost of 

 roads improved in New Jersey in 1914 and includes the state highway engi- 

 neer's report and a report of laboratory and experimental worli. 



Papers presented at the Pan American E-oad Congress (Good Roads, JfS 

 {1015), No. 19, pp. 2Jf9-259). — The following special papers are given: Dust 

 Suppression and Street Cleaning, by W. H. Connell ; Equipment for High- 

 way Work, by A. H. Blanchard ; Highway Bridges and Structures, by W. S. 

 Gearhart ; and Uniformity for Highway Statistics and Data, by H. E. Breed. 



Operation analysis of new machines which cheapen the moving of earth on 

 road work, A. B. McDaniel (Engin. Rec, 12 {1915), No. 5, pp. 126-128, figs. 

 .1, ) . — The conditions affecting the cost of operation of new types of graders and 

 scrapers and the light steam shovel are analyzed, and the ysefulness of the 

 full-circle steam shovel in tearing up old paving and making shallow cuts in 

 hard material and the economy of hauling graders and scrapers by tractors 

 are brought out. 



Relative twenty-year economy of various types of roads and pavements 

 {Engin. and Contract., 44 {1915), No. 5, pp. S9-91, figs. 2). — According to this 

 comparison, the cheapest road from the standpoint of 20-year cost for both 

 urban and rural service is the vitrified brick road built of brick on edge. In 

 order to realize the full economy of the brick road the brick must be laid on 

 edge. With reference to the relative 20-year economy of rural roads, it is 

 brought out that the small community which has to pay a high rate of interest 

 for its money is in a much better position to afTord a high-grade macadam road 

 than a more important community more fortunately situated as far as obtain- 

 ing money at a low rate of interest is concerned. 



Maintaining concrete and brick roads in Illinois, B. II. Pifpmeikr (Eiigin. 

 News, 7Jf {1915), No. 7, pp. SlO-313, figs. S).— A description of the methods of 

 maintaining concrete and brick pavements on .state-aided highways in Illinois 

 is given, together with cost data on practically all the more Important state 

 roads. A special motor truck, made by rebuilding a small runabout, and a 

 portable heating kettle outfit are used in this work. The data show that the 

 average cost of maintenance when the truck was used was about one-third less 

 than where the portable hand kettle was used. The cost of filling cracks and 

 joints ranged fi*om 0.1 to 0..57 cts. per square yard of pavement, varying usually 

 in proportion to the discontinuity of the pavement. " PYom a maintenance 

 standpoint it would be an advantage to have as few joints as possible. Four 

 years' experience in maintaining concrete pavements in Illinois indicates that 

 joints, even though protected with armor plates, require about the same atten- 

 tion as do the ordinary cracks." 



Bebuilding rural roads in the Southern States, G. B. Buchanan {Engin. 

 Ncics, 7.'f {1915), No. 10, pp. 4-'f6-US, figs. 4).— The peculiarities? of southern 

 rural road improvement are explained in the light of antebellum conditions, 

 and methods and costs of reconstructing corduroy roads are given. 



An investigation to determine the relative resistance to wear of concrete 

 made of different aggregates {Engin. aM Contract., 44 {1915), No. 8, pp. 144-- 

 147, figs. 21). — Tests to determine the influence on resistance to wear by con- 

 crete roads of the character and quality of stone used for the coarse aggregate 

 are reiwrted. These tests consisted of abrasive and gouging te^sts of 36-in. 

 rings of 1:2:4 concrete 8 in. thick. The gouging test was designed to repre- 

 sent the action of horseshoe calks. 



In the abrasive tests " it was found in the case of the gravel specimens that 

 when subjected to the action of the shot the gravel would kick out and produce 



