883 



From these values results: 



P* +P,7. + •. =P. 4- Pi. 6 4-P,7. + ...=P. +P». + Piso + •• ; (6) 

 and thus: 



p„. =0, P,. = 0, p,, = -2.10-5. (7) 



Supposing the coetTicients />« for large values of n to be of this 



order of magnitude also if [1 J 7^ 0°, we see that we are allowed 



to use the formula 



de 

 without, on this account, iiaving to fear an error in the resulting 



_ 1 "-1 / d a'\ 



(8) 



value of 



d« 



larger than half a unit of the fifth decimal, if 7i ^ 90. 



In the next table I have collected the values of — - — , computed 



de 



according to this formula; for [IJ = 0° 1 took n = 270, for the other 



a' 

 values of [11 n=:135; the values of the constants e and - are 



a 



those of the table on page 3 of the "Investigations". 



The function ^-^- is an even function of [Ij ; putting [IJ = 



q sin IÜ, q being a constant, the development becomes 

 d/([ll) 



de 



=: \p (tv) = S kin COS 2 nW 

 »i=0 



(9) 



I take q = -{- 36', thus putting [11 = + 36' sin w\ if from this 

 last equation we compute a value of lo in the tirst quadrant for 

 each value of [IJ from the preceding table, we have the value of 

 ip(M>) for six values of w and thus six linear equations, from which, 



