544 



SCIENCE 



[N. S. Vol. XLVII. No. 1222 



general repairs can be made successfully with cold 

 bituminous preparations. 



The efficiency of the application of cold bitumi- 

 nous materials for surface treatments on gravel and 

 hroTcen stone roads: Julius Adleb. In the devel- 

 opment of bituminous surface treatment practise 

 during the past ten years, the most important step 

 forward has been the recognition of the funda- 

 mental necessity of a road well built in every re- 

 spect, and having a mosaic surface especially 

 adapted to receive the bituminous material. In 

 the selection of the latter, a greater and desirable 

 degree of uniformity of practise will follow upon 

 a clear understanding of the characteristics which 

 identify them as most suitable to serve the two 

 functions of: (a) Priming; (fe) smoothing and 

 rendering impervious the road surface. The pre- 

 cise limits of suitability of bituminous-treated 

 roads can hardly be determined deiinitely in 

 traffic units because of the difference in materials 

 in use, and combined traffic and climatic conditions. 

 From an economical standpoint, they represent a 

 high annual miaintenance charge which is an argu- 

 ment in favor of their use in the preservation of 

 existing roads, rather than in a program of new 

 construction. The full possibilities in their use, 

 however, will not be realized until high-grade orig- 

 inal construction, scientific selection of materials 

 and systematic maintenance are all combined. 



Present status of granite block pavements : C. D. 

 Pollock. This paper describes the improvement 

 of the granite blocli pavement from its early form 

 to the latest types of smooth surface, close jointed 

 pavements. The latest and best joint fillers are 

 shown and likewise the various cushions or beds 

 for the blocks. The great improvements which 

 have been brought about in making granite blocks 

 and also in laying this pavement, in recent years, 

 are due entirely to the cooperation between the 

 engineers and the quarrymen. The engineers 

 learned enough of quarrying to draw specifica- 

 tions calling for the best practicable block and the 

 qnarrymen have exerted themselves to make that 

 block. 



Battler tests for paving bricTc of various depths: 

 WiLLiiM C. Perkins. Discussion of the rattler 

 used for testing paving brick and a short history 

 of same. The testing of paving brick of different 

 depth and the theoretical determination of an al- 

 lowance or differential for same. Discussion of a 

 modification of the abrasive charge in rattler in 

 the testing of paving brick. 



Motor truclcs and long distance highway trans- 

 portation: Maurice B. Greenough. Statistics 



show that the railroads have nearly if not quite 

 reached the limit of their capacity for freight 

 hauling. At the same time there is a growing 

 shortage of cars. They themselves have advo- 

 cated the use of motor trucks on the public high- 

 ways for short hauls to relieve congestion. In- 

 creased highway construction and organized effort 

 to encourage the use of highways are essential to 

 make the potential relief an actuality. 



The construction and maintenance of highways 

 under war conditions: Arthur H. Blanchard. 

 Since the United States entered the war, motor 

 truck transportation on country highways has 

 rapidly developed due to the following causes: 

 Pirst, the marked increase in the tonnage and 

 bulk of shipments; second, the lack of railroad 

 equipment to efficiently handle freight and ex- 

 press transportation; third, the inadequacy of 

 railroad terminal facilities; fourth, the United 

 States government priority orders; and fifth, the 

 intensified consideration of economic problems, 

 the solution of which would lower prices of the 

 necessities of life. Suggestions relative to con- 

 struction and maintenance of highways under war 

 conditions: (1) Maximum use of motor truck 

 transportation of materials and machinery; (2) 

 amendment of onerous traffic regulations which 

 prevent economic use of motor trucks; (3) modi- 

 fication of state laws to permit construction and 

 maintenance of highways by day labor; (4) 

 award of contracts to responsible contractors on a 

 cost plus a profit on labor and rental of equip- 

 ment, all materials being furnished by the state or 

 county; (5) modification of contracts and specifi- 

 cations which place all liabilities on contractors; 

 (6) maximum use of labor-saving machinery; (7) 

 maximum utilization of convicts and prisoners of 

 war; (8) construction and maintenance of mili- 

 tary highways by the United States government. 



The second session was held on the afternoon 

 of December 28 in the Lecture Hall of the Mellon 

 Institute, Vice-president Dr. Henry S. Drinker in 

 the chair, with an attendance of about one hun- 

 dred ten. This meeting was a joint session with 

 Section C; Society for the Promotion of Engi- 

 neering Education; Engineer's Society of West- 

 ern Pennsylvania; Pittsburgh Section, American 

 Electro-Chemical Society, and the Pittsburgh Sec- 

 tion, American Chemical Society. The program of 

 the session was as follows: 



Vice-presidential address, some needs of engi- 

 neering : Dr. Henry M. Howh. Printed in the is- 

 sue of Science for January 25. 



