TTie Reader is requested to make the following Correctmit: 



In formulae A'). rea(/ V=f^z,—lJ.WW-\-iJ./[(z,+ A)»d*,+{x, +B) ^djS,] 



In ( V'),for z^ + y» read x" + y' 



Before [A"), for "and is" read "and supposing Wj,^ j= 0, and is" 



In formula (B") of First Supplement, for z read x. 



