OFFICE OF PUBLIC EOADS. 



769 



previous year. In addition to these, 5 special surveys and 4 bridge 

 ms]iections, involving the jireparation of ])lans and estimates, were 

 made. 



In the routine testing of road materials in the laboratories a 

 notable gain was shown as com])ared with any previous year. The 

 total number of such tests was 1,168 as compared with 735 for the 

 fiscal year 1909, wliich in turn was the largest for any one year since 

 the establishment of the Ollice. 



The laboratory investigation and testing of bituminous binders 

 has grown to be a very imj)ortant and extensive section of the labora- 

 tory work. Suitable facilities were not provided, however, for these 

 investigations until near the close of the fiscal year. 



The collection of data relating to road mileage begun in December, 

 1909, was about one-half completed at the close of the fiscal year. 



On the whole, it may be conservatively stated that the work of the 

 fiscal 3^ear 1910 exceeded the work of the best previous year in amount 

 by at least 50 per cent. The personnel is better organized and more 

 famihar with the duties required of it; the methods for conducting 

 work have become more nearly standardized; and a better system 

 prevails along all lines. In the efhciency of work done the Office 

 nas certainly made a gain commensurate with the increase in the 

 amount of work. 



The detailed reports of the work i)erformed under each project 

 are given in this report as follows. 



OBJECT-LESSON AND EXPERIMENTAL ROADS. 



Object-lesson roads are constructed for the purpose of giving prac- 

 tical instruction to local road builders of the methods of road building. 

 The Oilice furnishes, at government expense, one or more engineers, 

 who make the necessary surveys, estimates, and specifications, 

 supervise construction, and give theoretical instruction, while the 

 local authorities furnish all machinery, materials, and labor. During 

 the past 3^ear 6 roads which had been begun in the last fiscal year 

 were completed, 49 were begun and comjifeted during the year, and 

 2 were unfinished on June 30, 1910, and will be reported in the next 

 annual report. Classed according to materials of construction 

 these roads were as follows: 3 bituminous macadam, 1 oil-gravel, 6 

 macadam, 6 gravel, 27 sand-clay, 10 earth, 1 concrete, 1 slag, and 1 

 brick. For the purpose of comparison the following table is given, 

 showing the number of square yards of each type of road constructed 

 during the fiscal years 1905, 1906, 1907, 1908, 1909, and 1910: 



Object-lesson roads constructed during 1905, 1906, 1907, 1908, 1909, and 1910. 



73477°— .VCK 1010- 



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