BUREAU OF PUBLIC EOADS. 387 



Investigations are being continued upon reinforced concrete slabs, 

 wear measurements of experimental concrete roads, and the pressure 

 developed against concrete forms under various heads at diHerent 

 stages of pouring concrete. 



ROAD AND BRIDGE FOUNDATION TESTS. 



Investigations have been continued upon pressures resulting from 

 hydraulic fills. This work was conducted in cooperation with the 

 Miami conservancy district, and the results of investigations have 

 been worked into such shapes as to be of considerable value to engi- 

 neers. Field tests with apparatus devised in the office have also been 

 made on earth fills in the vicinity of Washington. A paper upon 

 " Tests to Determine Pressure Due to Hydraulic Fills '' was pub- 

 lished in the April number of Engineering News. 



It is planned to conduct investigations relative to pressure distri- 

 bution through soils serving as subgi^ade for various types of pave- 

 ments. Information along this line is urgently needed by highway 

 engineers owing to the increasingly heavy loads which roads are now 

 being called upon to carry. 



FARM-IRRIGATION INVESTIGATIONS. 



The Division of Farm Irrigation continued its established lines 

 of work with some curtailment on account of war necessities and the 

 loss of employees to the military service. While maintaining the 

 continuity of studies already in progress, effort has been mad'e to 

 render these of immediate practical value, especially where increased 

 food production might be encouraged thereb}'. Thus, by the publi- 

 cation of practical bulletins, by correspondence, and by the personal 

 efforts of employees in the field, improved methods of utilizing water 

 in irrigation have been effected and the farmers in irrigated sections 

 have been induced to put forth greater efforts on account of the as- 

 sistance given. 



For the double purpose of effecting economy in administration and 

 of bringing the activities of the division into immediate touch with the 

 western country, its headquarters were transferred during the spring 

 of 1918 from Washington, D. C, to Berkeley, Cal. The wisdom of 

 this move was demonstrated promptly, as many appeals for advice 

 and assistance from farmers and communities were met, which could 

 have received only belated attention at best under the former ar- 

 rangements. The design and installation of small reservoirs and 

 pumping plants, and the preparation of land for irrigation in re- 

 sponse to calls, especially from more or less isolated communities, were 

 much facilitated by this change of headquarters. 



Although advancing prices and cost of equipment and shortage 

 of labor have cut down materially the extension of pumping for 

 irrigation from underground sources in many localities of the West, 

 it has been possible to maintain some degree of this extension by 

 the demonstration of cheaper methods of well-sinking and pumping 

 in sections where established methods had been based on local prac- 

 tice without reference to methods developed with better success in 

 similar conditions elsewhere. Notably on the Great Plains, this 



