STREAMFLOW EXPERIMENTS 405 



(g) Volume to crest of flood on A: 



In this first period (40 days out of a total of 07 for the whole 

 f^ood) the most probable discharge of B was 2.115 ins. O. W. and its 

 actual discharge 2.T27 ins. O. W., or an excess of 39 per cent. 



Rough calculations indicate that on some days in the early stages of 

 the flood stream B may have discharged 100 per cent more than would 

 have been expected under forest conditions. 



3. Relations in the summer rainy period : 

 (a) From end of flood to July j/; 



In this 18-day period the flow of stream B was 0.242 ins. O. \V., or 

 only 0.8 per cent above that to be expected. 



{b) Month of August: 



The discharge of stream B was .341 ins. O. W., or 2.4 per cent in 

 excess of the expected. 



(c) Month of September: 



The discharge of stream B w^as .331 ins. O. \V., or 4.4 per cent in 

 excess of that to be expected, all things considered. 



(rf) A check on the three preceding calculations, by one calculation 

 for the whole period, shows no appreciable correction to be applied to 

 the months. This shows an excess in the discharge of B of 2.8 per cent 

 for the whole period. 



{e) Last five days of September: 



This period is almost always rainless and permits us to examine the 

 relation of the streams wdien not influenced by any current precipita- 

 tion. In 1920 all of the 5 days were without rain. 



Calculations for 1920 indicate stream B w-as running 2 per cent above 

 the usual, at this time. 



4. Relations for the period October 1, 1919, to beginning of flood 

 in 1920, the freezing period : 



Admittedly, in .the effort to cover this long period by one calculation, 

 only a rough approximation to the most probable flow of stream B is 

 possible. Unless a number of years' results give very consistent eflfects 

 ascribable to denudation, it w^ill be necessary to devise formulae for 

 different parts of the winter period. The whole, however, is to be 

 thought of as one for the storing-up of water for the next growing 

 season. 



