884 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



New Hampshire Hio;hways; 43, Highway Bridges and Culverts 

 (revision ()f Bulletin :)0) ; and 44, The Physical Testing of Rocks for 

 Road Building. Bulletin No. 36 is one of the most important of our 

 bulletins. It supersedes a publication which was originally pre- 

 pared for the Alaska, Yukon and Pacific Exposition, and is now 

 widely used by the road trains. No. 37 is a revision of Bulletin 31. 

 No. 38 should be used in connection with Bulletin 34 and explains 

 the methods used in the Chemical Laboratory of this office for test- 

 ing tar and oil dust preventives. Bulletin 39 is the first publication 

 of this office on the subject of bridges and culverts; other publica- 

 tions on this subject will be issued during the coming fiscal year. 

 Bulletin No. 40 is the second of the series of bulletins telling of the 

 road-material resources in the various States of the Union. No. 41 

 is the result of a very elaborate inquiry dealing with mileage and 

 road expenditures throughout the United States. The edition of 

 this bulletin was very limited, and a second edition has been issued 

 as House Document No. 582. No. 42 deals with a special investiga- 

 tion concerning New Hampshire highways, prepared by this office 

 with the cooperation of the governor of New Hampshire. It is the 

 most elaborately illustrated of any of the publications of this office. 

 No. 43 is a revised edition of Bulletin 39. Owing to misunderstand- 

 ing among engineers as to the scope of assistance offered by this 

 office, it was deemed necessary to issue No. 39 in a revised form, 

 which would explain more fuUy just what the office is prepared to 

 undertake in the field of bridge engineering. No. 44 is a very com- 

 plete account of the rock tests conducted by this office and by the 

 Massachusetts State Highway Commission before the testing labora- 

 tory was established in this office. To a certain extent this publica- 

 tion is a revision of Bureau of Chemistry Bulletin 79, which was 

 issued in 1903. 



Two circulars were issued, both dealing with studies of bituminous 

 products. Circular 96 treats of " Napthalene in Road Tars," and 

 Circular 97 is entitled " Coke-Oven Tars in the United States." 



Two yearbook articles were published separately after appearing 

 in the Yearbook for 1911. These are No. 535, " Progress and present 

 status of the good-roads movement in the United States," and No. 

 638;, " Bituminous dust preventives and road binders." 



The foregoing documents, together with the Annual Report of the 

 Office of Public Roads for 1911, make up the 16 publications which 

 were issued during the past fiscal year. 



During this year the work of preparing a bulletin on the subject of 

 " Oil-mixed Portland-cement concrete," was completed, but since 

 the bulletin was not published in the fiscal year 1911 it will be dis- 

 cussed in the next annual report. 



New publications are in course of preparation on the following 

 subjects : The condition and administration of roads in foreign coun- 

 tries; road maintenance; short-span bridges and culverts; inorganic 

 road materials; the work of the office of public roads; the expansion 

 and contraction of concrete roads; the preparation of refined water 

 gas tar binders; the methods of testing bituminous road materials 

 (supplementary to bulletin 38) ; and the investigation of reinforced 

 concrete slabs. 



