CORRECTION. 



In addition to the Correction in Vol. iii, No. 3, January 20, 1921, on page 

 149, Vol. iii. No. 2, November 20, 1920, line 13, for 92.57 read 89.10; page 154, 

 lines 15, 28, and 32, for read O+IO; page 155, line 3 of the figure legend, 

 for O read 0+10. 



