1902.] 



Correlation betiveen Barometric Heights. 



465 



" On the Correlation between the Barometric Height at Stations 

 on the Eastern Side of the Atlantic." By Miss F. E. Cave- 

 Browne-Cave, Eesearch Student of Girton College, Cam- 

 bridge, with some assistance from Karl Pearson, F.B.S., 

 University College, London. Eeceived June 3, — Bead June 

 19, 1902. 



(1.) In a memoir on the correlation and variation of the barometric 

 height at divers stations in the British Isles' 55 ' by Professor Karl 

 Pearson and Dr. Alice Lee, it is suggested (i) that interesting results 

 might be obtained by correlating the barometer at stations on the east 

 .and west sides of the Atlantic, allowing an interval of time between the 

 observations (see p. 459), and (ii) that with a certain distance between 

 stations, the correlation! would be found to be negative, i.e., a high 

 barometer at the one station corresponding to a low barometer at the 

 second (see p. 467). 



(2.) In order to deal with these points, steps were taken in 1897 to 

 collect the necessary material. Twenty years, 1879 — 1898 inclusive, 

 were selected for consideration, and the early morning barometric 

 observations for these years, copied from material provided by the 

 kindness of the British Meteorological Office for the following East 

 Atlantic stations : — B0d0, Floro, Skuclesnaes, Valencia, Lisbon, and 

 Funchal. These give a very fair chain of stations from the north of 

 Norway to Madeira. On the west side of the Atlantic we obtained 

 data for the same years for Halifax and Toronto by aid of the 

 Director of the Canadian Meteorological Service. So far as we can 

 judge the Canadian returns appear satisfactory and satisfactorily 

 copied, and we have heartily to thank the Director for nominating an 

 efficient and careful copyist. An appeal to the American Weather 

 Bureau in Washington, and later to the Smithsonian Institute, led the 

 latter institution to kindly offer a copy of the American data for New 

 York, Wilmington, and Key West, free of expense to us. We regret, 

 however, that the copy thus procured has been discovered after some 

 work upon it to be unreliable. We still trust, however, that we 

 may be able to proceed to work on accurate copies of the American 

 observations. 



(3.) Meanwhile a preliminary study has been made of the East 

 * ' Phil. Trans.,' A, vol. 190 (1897), pp. 423—469. 



f The first application of the mathematical theory of correlation to meteorology 

 occurs in the paper just cited. Samples of harometric correlation tables are 

 there printed, and it is shown how the mean height of the barometer at Station A 

 for a given height at Station B may be expressed in terms of standard deviations 

 and correlation coefficients. An elementary account of correlation will be found 

 in the ' Journal of the Eoy. Statis. Soc.,' vol. 60, pp. 1—44, by G-. U. Yule. 



