Mabch 10, 1911] 



SCIENCE 



»93 



the association and chairman of Section D, pre- 

 sided at all meetings of the section and at the 

 joint session of Sections B and D. 



The officers for the Washington meeting of the 

 section are as follows: 



Vioe-president — C. S. Howe, Case School of Ap- 

 plied Science. 



Retiring Vice-president — A. Lawrence Rotcli, 

 Blue Hill Observatory. 



Secretary — G. W. Bissell, Michigan Agricul- 

 tural College. 



Member of the Council — ^A. F. Zahm, Washing- 

 ton, D. C. 



Member of General Committee — 0. F. Marvin, 

 University of Kansas. 



Sectional Committee — J. E. Boyd, Ohio State 

 University; A. H. Blanchard, Brown University; 

 C. M. Woodward, Washington University; W. J. 

 Humphreys, Mount Weather Observatory; G. 0. 

 Squier, U. S. A. 



Herewith are titles and abstracts of the papers 

 presented : 



The Amount of Stream-flow in the Northern 



Prairies: E. F. Chandler, University of North 



Dakota. 



In the prairie regions of the northern United 

 States, there have been until lately no stream- 

 flow records available. Within the past decade, 

 the U. S. Geological Survey and other agencies 

 have maintained fairly ' extensive records here. 

 It is now known that in this region the stream- 

 flow or " run-off " is far less than formerly sup- 

 posed. In North Dakota, as a particular example, 

 it is seen that some former estimates were as 

 much as 500 per cent, in error, for the average 

 annual run-oft is less than one inch and the total 

 of a single year is frequently less than one half 

 inch. 



The run-oft' from any drainage area depends 

 upon its topography, geological structure, etc., 

 and upon its total rain-fall and the seasonal dis- 

 tribution and intensity of the rains. But where 

 the run-oflf is as small as here considered, it is 

 very improper and misleading to follow the fre- 

 quent custom of speaking, of the run-off as a 

 percentage of the rainfall. 



The only basis upon which any reasonable esti- 

 mates can be made is a comprehensive set of rain- 

 fall and stream-flow records extending through a 

 long period of years. Eain-fall records alone are 

 not sufficient; this statement applies especially 

 to regions where the stream-flow is only a small 

 percentage of the rainfall. 

 Consequence of Solution of Air in the Hydraulic 



Air Compressor: F. W. McNair and Geo. A. 

 KoENiG, Houghton, Mich. 



Brief description of the Taylor compressor at 

 the Victoria Mine, difficulty with lights in the 

 mine, plan of the mine, conditions due to " com- 

 pressor air " as affecting lights and men, com- 

 ment on efficiency of compressor, desirability of 

 further investigation; being a brief rfeum4 of the 

 results of an investigation made in the spring of 

 1907 by the authors. 



A Comparison of English and American, Traffic 

 Regulations: A. H. Blanchard, Brown Uni- 

 versity, and H. B. Drowne, Providence, R. I. 

 From the standpoint of the highway engineer 

 the following regulations should be made a part 

 of the laws relative to the use of highways by 

 various kinds of traffic. The proposed regula- 

 tions are based on conclusions arrived at after a 

 careful consideration of the effect of various 

 classes of traffic on road surfaces as exemplified 

 by American and European practice. 



1. All horse-drawn vehicles shall be equipped 

 with a light or lights. 



2. All vehicles, either horse-drawn or motor- 

 driven, having iron tires and using the improved 

 state roads shall be provided with tires of widths 

 such that for a 2-foot wheel 500 pounds shall be 

 the maximum pressure per linear inch of width 

 per wheel, but an additional pressure of 30 pounds 

 per inch shall be allowed for each additional 

 3 inches in diameter. The maximum width of 

 tires for horse-drawn vehicles shall be 6 inches. 

 All iron tires must be smooth. The width out 

 to out of all classes of vehicles, including the 

 superimposed load, shall not exceed 8 feet. 



3. The maximum speed of motor cars on all 

 highways shall not be greater than is reasonable 

 and proper, having regard to all classes of traffic 

 and local environment. 



4. Vehicles shall be so constructed that the 

 driver or operator shall sit on the left rather 

 than on the right. 



5. Motor cars (including traction engines) 

 hauling trailers shall keep to the right side of 

 the center of the road. No more than three trail- 

 ers shall be allowed in any train. Pneumatic 

 tires or tires made of soft or elastic material 

 shall not be equipped with chains, metal studs 

 or some other non-skidding device of this char- 

 acter except in the case of passenger veliicles 

 carrying not more than seven persons. 



6. The intensity of powerful acetylene lights on 

 motor vehicles, including those running on rails, 

 shall be diminished on the approach of other 

 vehicles. 



