536 Mr. L. Scliwendler on the General Theory 



a = h is therefore the second regularity-condition, the fulfil- 

 ment of which makes the relative disturbance of balance by a 

 variation of K and A, as small as possible. 



Substituting now a' = U in the expression of the D disturb- 

 ances, and remembering that 



R' = K', 



we get 



D / 2 = 5 i 7 SR / , 



Thus D'! and D' 2 , for constant s, X', and t/, become smaller 

 the smaller ^ f is, while D' 3 becomes smaller the smaller 



T . 



^is. 



Now remembering that 



T i+v+pf' 



and 



(i»+ P ")(i+i'+p>)+i(i'+ P ') 

 . i+v+p" 



. £_ \i + l"+p"f 



* * W~i{(l"+p'%i+l r +p')+i(J!+fOY 



T _ i + l" + p" _ 1 



For a tolerably good line Z" + p" as well as V + p' can be 

 taken as small in comparison with i ; hence, approximately, 



J _ 1 _ 1 



and 



K' > 



from which it follows that also for the compensation method 

 p 1 and p" should be selected as large as possible. 



But p = a +f does not give a condition besides that we know 

 we should select a and / absolutely not small. 



