410 Miss F. E. Cave-Browne-Cave. Influence of the [Dec. 20 y 

 Table IV. Correlation of Daily Rise at Halifax and Wilmington. 



of very little significance. But it does occur in a very marked way for 

 the time relations when we correlate the daily rise at the two stations. 

 This analogy strengthens our belief that the intervals of maximum 

 correlation are of great importance from the standpoint of atmospherical 

 physics, and our desire to see the practical meteorologist's explanation 

 of the matter is correspondingly increased. 



7. The magnitude of the correlations which have been found to 

 exist between the readings on consecutive days at Wilmington and 

 Halifax, suggests the possibility of predicting barometric heights at 

 the latter station, with a fair degree of accuracy from the heights 

 observed at Wilmington on the previous day. In the paper by 

 Professor Pearson and Dr. Lee already referred to, a table is given 

 showing the barometric heights at Stonyhurst on 50 days, calculated 

 from the simultaneous readings at Southampton and Laudale. The 

 difference between the calculated and observed heights at Stonyhurst 

 was small in every case, the mean value being about ^/'. At that 

 time no correlations had been calculated between observations taken 

 on different days; but the values now obtained make it possible to 

 apply the theory to actual prediction. In predicting for Halifax from 

 a single station more than 1000 miles away, we are naturally unable 

 to obtain such good results, but, on the other hand, we have the 

 advantage of calculating the probable heights at Halifax a day before- 

 hand. In order to see how far the prediction is verified, forty dates 

 were taken at random, one in summer, and one in winter for each 

 year. It was impossible to allow the best intervals, 16 hours in 

 summer, and 23 in winter, as we do not possess readings for 

 Wilmington taken at the required times, and the predictions have, 

 therefore, been made with the interval of 26 hours for the first 10 years r 

 and 25 for the second. 



* Positive when the readings are taken later at Halifax. 



