SUMMARY. 77 



equations, which thus provide a means of computing the wilting 

 coefficient when direct determinations are not feasible. 



m ., . _ . , moisture equivalent 



* iltmg coefficients lM (1±Q QQ7) • 



m ., . _ . hygroscopic coefficient 

 Wilting coefficients—^ (1±0 . 018) 



__.. . „ . moisture-holding capacity— 21 

 Wilting coefficients- 2.90 (1+0.021) ' 



TO ., . „ . 0.01 sand-0.12 silt— 0.57 clav 

 ^iltmg coefficients — (1±0.025) ' 



The second term of the quantity within the parentheses shows the 

 probable error of the relationship in each case and constitutes a 

 measure of the relative accuracy of the different methods. 



The moisture-equivalent method, in which the measurements are 

 made with the aid of the centrifugal machine exerting a force 1,000 

 times that of gravity, is the most accurate and satisfactory of the 

 indirect methods. 



230 



