54 



1'r. (,\ Chree. //</*>//'/"//. 



Aii idea of the degree of accuracy in the two cases is ail'or<lr<l liy tho 

 two following tables. The first gives the observed values of KO on the 

 days of regular observation since Calibration IV was made ; the second 

 gives the corresponding values found for the fundamental intr : \.-il.-. 

 In the first table I give separately the values found when an allowance 

 for the observed difference between the leads is omitted and applied. 



Table XXL Observed Values of IV 



Table XXII. Observed Values of th Fundamental Interval (leads 

 not interchanged). 





The data in 

 Kew results. 



Tables XXI and XXII are 

 They were taken during a 



a very fair sample of the 

 time when the difference 



