April 11, 1913] 



SCIENCE 



573 



Boft in hot weather — nor become brittle in cold 

 weather. 



It should be composed of such materials that 

 would be and remain stable under all conditions 

 and not evaporate or lose its most valuable prop- 

 erties. 



It should be applied in the best and most ap- 

 proved manner, so as to produce the best results 

 capable for the quality of the bitumen. The sur- 

 face of the brick should be made perfectly clean, 

 free from dust and moisture. The bitumen should 

 be applied at the proper temperature — in a proper 

 manner and under favorable weather conditions. 

 After application of the bitumen the surface 

 should be covered with either fine granite or trap 

 chips, torpedo sand or a coarse sand. 



Such a bituminous coating would make the ideal 

 brick pavement. 



Small Stone Block Pavements : A. H. Blanchakd, 

 professor of highway engineering, Columbia 

 University, New York City. 



Illustrated with lantern slides of European and 



American pavements of this type. 



The Organization of Town Highway Departments: 



Feed Buck, assistant deputy commissioner. New 



York State Highway Department, Albany, N. Y. 



There are three essential points to be observed 



in formulating any plan for the improvement of 



the highways of any commonwealth. 



(a) A series of improved thoroughfares con- 

 necting the principal centers of population. 



(6) A series of improvements to the highways 

 which form the principal tributaries to those first 

 mentioned. 



(c) All highways in the commonwealth not in- 

 cluded in the first two classes. 



No plan for financing a scheme of higliway 

 improvement has yet been advanced which will 

 make possible the improvement of a total of more 

 than 12 per cent, of the mileage of any state, of 

 the character indicated for classes (a) and (6) 

 within the next 15 or 20 years ; and any plan which 

 contemplates the improvement of 12 per cent, of 

 the mileage of any commonwealth without giving 

 attention of some kind to the remaining 88 per 

 cent., fails in large measure of attaining its full 

 value to the commonwealth as a whole. 



Roads comprising class (c), in this article, are, 

 in the state of New York, under the jurisdiction 

 of the Bureau of Town Highways, and since the 

 organization of that bureau, very gratifying re- 

 sults have been accomplished. 



With no greater town taxes than were raised 



under the old "Labor System," about 3,600 

 miles of good town macadam roads have been 

 built, about 8,400 miles of good gravel roads, and 

 about 50,000 miles have been properly shaped 

 and crowned and standardized as to width. 



By furnishing plans and encouraging town 

 superintendents to construct culverts and short- 

 span bridges with their own local labor, utilizing 

 local materials wherever possible, in 1911 there 

 was effected a saving, in actual cash, to the tax- 

 payers of the state more than three hundred and 

 fifty thousand dollars, not taking into any account 

 the vastly superior strength and durability of the 

 structures so erected. 



The results of the plan in New York seem to 

 clearly prove that a thoroughly organized, well 

 equipped town highway department is one of the 

 essential parts of any general scheme of highway 

 improvement. 

 BricJc Pa/oements for County Highways: W. C. 



Perkins, Niagara Falls, N. Y. 



Presented by the author, and illustrated by 

 lantern slides. 

 A City Traffic Census: W. H. Messenger, S.B., 



assistant engineer, Bureau of Highways, Brook- 

 lyn, N. Y. 



The above bureau inaugurated a permanent cen- 

 sus of its vehicular traffic in June, 1912. The 

 forms used divide traffic into two large classes, 

 rubber-tired and iron-tired, with appropriate sub- 

 divisions of each class. Starting with a small 

 squad of six men, working eight hours a day, rain 

 or shine, observations have been made at some 400 

 points mostly in duplicate. Duplicate observations 

 are separated by a period of 15 days. A few night 

 and Sunday records have been taken. 



Results are tabulated to give the density and 

 tonnage. The density is computed for number per 

 foot of roadway per minute, per line of traffic 

 per minute, and on the basis of traffic units as 

 used by the London Traffic Branch. Tonnages are 

 founded on extensive inquiry among those best 

 knowing weights of different vehicles of business 

 and recreation, and are assembled to give daily, 

 weekly and annual amounts per foot of width of 

 roadway, to the end that durability or total life 

 may eventually be found for all classes of pave- 

 ment. 



The results thus far obtained have been used 

 by the city planning committee, and are daily 

 called for in connection with the determination of 

 the class of pavements to be laid on certain streets 

 in the immediate future. 



