288 EXPERIMENT STATION RECOED. 



Report of public works of Dutch India {Verdag Burgerl. Openh. Werken 

 Nederland. Indie, 1910, pt. 4, pp. 269, pis. 31). — This report deals with irriga- 

 tion and with the conveyance, diversion, and storage of water supplies includ- 

 ing both projected and finished works. Detailed plans, maps, charts, and 

 hydraulic and other data accompany the report. 



Behavior of cup current meters under conditions not covered by standard 

 ratings, F. C. Scobey (U. S. Dept. A<gr., Jour. Agr. Research, 2 {1914), ^o. 2, 

 pp. 77-83, pis. 2, figs. 2). — Tests made to determine the applicability of standard 

 ratings when the meter is held near the water surface, near the sides or bottom 

 of the channel, or out of horizontal, and to determine the effect of the move- 

 ment of the meter in the water when the " integration " method is used, and 

 of dulling the pivot bearing of the meter, are reported and discussed, the results 

 obtained being compared with those of a standard rating 



The main point brought out is that the cup current meter should be actually 

 rated at the surface and bottom of the channel if it is to be operated at these 

 points. The importance of keeping the meter horizontal is also clearly indi- 

 cated. The added friction due to dulling the pivot bearing had more influence 

 at low velocities, and for velocities greater than 1 ft. per second the sharpness 

 of the pivot was immaterial. When held close against the vertical concrete 

 wall of the channel so that the open and closed sides of the turbine were 

 brought next to the wall alternately, the meter ran true to the standard curve 

 but disregarded the cycloidal motion of the water. 



All vertical movement of the meter when the vertical integration method 

 was used tended to turn the wheel in the same direction as did the flowing 

 water. For slower movements of the meter this tendency was insuflicient 

 to overcome the internal friction in the meter, but when it was operated in 

 running water the water overcame the internal friction and the force due to 

 the vertical movement of the water was still available to turn the wheel and 

 cause it to overregister. " It appears that a cup meter underregisters at all 

 points nearer the surface than about 0.3 ft., and also while very near the 

 bottom. Therefore, in a process of vertical integration with a cup meter there 

 is a tendency to overreglstration at all times due to the vertical motion, and 

 a tendency to underregistration while the meter is passing from 0.3 ft. below 

 the surface up to the surface and back to that point and while near the bottom." 

 Cost and methods of clearing land in the Lake States, H. Thompson and 

 E. D. Strait (U. 8. Dept. Agr. Bill. 91 (1914), PP- 25, figs. 10).— This bulletin 

 gives detailed cost data and discusses laud clearing in Michigan, Wisconsin, 

 and Minnesota by explosives alone, by explosives used in connection with 

 stump pullers or block and tackle, by stump pullers alone, and by power ma- 

 chinery. In addition data of the work of clearing 20 different tracts are 

 presented. 



There are said to be approximately 11,954,628 acres of logged-off land in 

 Michigan, 10,792.100 acres in Wisconsin, and 11,768.000 acres in Minnesota, 

 a large part of which will make good agricultural land if cleared and properly 

 managed. 



"Cutting and burning the second growth, pasturing for several years, and 

 keeping down all sprout growth is the most economical method of handling all 

 logged-off lands before stumping them. Explosives play an important part in 

 clearing land. On the heavier soils dynamite, with 20 to 30 per cent of nitro- 

 glycerin or its equivalent, is to be preferred. Cooperative buying in large 

 quantities is recommended. Stump pullers reduce the cost of stumping on 

 lighter soils. On the heavier soils the difference between the cost of clearing 

 by explosives and by the use of stump pullers is very slight. 



