520 Dr. A. D. Waller. Various Inclinations of the [Mar. 6, 



Dr. E. — The superior angle a can be estimated without difficulty from the values of the right and left 

 superior spikes — 



12-5 + 7-5 20 . . _„„ 



tan a = ' = — = 4. a = 76 . 



12-5-7-5 5 



But the mixed character of the right and left lateral spikes, viz., positive followed by negative, does 

 not afford assured data for calculation (see text, p. 512). Taking into the formula the positive values 

 7"5 and 5, the angle comes out as 22°. Taking a positive value 7'5 and a negative value —25, a = 105°. 

 Taking the negative values —12 5 and —25, a = 34° of reversed current direction. But I place no 

 reliance on these figures. 



