OF ARTS AND SCIENCES. 



421 



rw, n , • /.00003898 n^co/. 



The mean error of one observation = w = ± .OOzob 



„ „ „ the result = ^/^^ = ± .00083U 



The probable error of one observ'n. = .67449 \/^ — -^^ — = ± .00159 



J> M V 



the result =.67449 



/. 00003898 



¥7X8 



± .00056278 



T am indebted to Professor Trowbridge for much kind advice 

 and assistance in the course of my work. 



