408 



Reports on Special Researches 



ing the curves for these two sections, making use of such observations as were available, 

 that this assumption was approximately justified. If an attempt were made to utihze 

 the diurnal- variation curves for separate sections of the cruise, it would involve using curves 

 in which the form was determined by observations on a comparatively small number of 

 days, and such a procedure was not deemed desirable. In any case, the use of the mean 

 diurnal-variation curve for the tohole period involved is roughly justified for the correction 

 of the mean values over that period. The diurnal- variation curves were obtained only for 

 X, n+,and R,&nd in the reductions made in Table 85, it has been assumed, as an approxima- 

 tion, that the form of the curve would be practically the same for rj+ as forn_, X+, and X_. 

 This assumption is, of course, only a rough approximation, for, among other things, it 

 attributes no diurnal variation to n+/?i_; but, as will readily be appreciated, it was not 

 practicable to carry out complete diurnal-variation determination of all the elements. 



In Table 85, the Atlantic-Ocean values from Brooklyn to Colon have been omitted 

 because it is felt that the observations there were too few in number to render them char- 

 acteristic of the whole ocean. Further, as already stated, the vessel was relatively near 

 land when these observations were taken, so that from this standpoint also the data can 

 hardly be considered as typical of ocean values. As a matter of fact, the inclusion of these 

 values in the total means would hardly affect the result m view of their small number. 

 It will be seen that there is no marked difference between the means for the Pacific and sub- 

 Antarctic Oceans, and, indeed, the quantities representmg the mean of the mean values for 

 each of these regions are sensibly the same as the direct means for the whole set. 



It is of interest to compare the values recorded in Table 85 with mean values obtained 

 by other observers, on land and sea. Tables 86-92 contam a collection of values obtained 

 by various observers in different locaUties. They have been drawn largely from pages 

 205-209, and page 265 of the article by E. von Schweidler and K. W. F. Kohhausch on 

 " Atmospharische Elektrizitat und des Magnetismus" (a section from vol. 3 of "Handbuch 

 der Elektrizitat und des Magnetismus," edited by L. Graetz). Some of the values recorded 

 as land values were really measured over lakes, but except in the case of lakes of large 

 area, the characteristics which control such measurements may reasonably be supposed to 

 be those of the land. 



COLLECTION OF LAND AND OCEAN VALUES OF ATMOSPHERIC-ELECTRIC ELEMENTS AS 

 OBTAINED BY VARIOUS OBSERVERS IN DIFFERENT LOCALITIES. 



Table 86. — Ionic Content {Land Valxies). 



Observer 



Ludeling .... 

 Liideling. . . . 

 Schweidler , . . 

 Schweidler . . . 



Ebert 



Ebert 



Simpson 



Gockel 



Wagner 



Hes3 and von 

 Sensel. 



Dorno 



Daunderer. . . 

 Speranski .... 

 Kohlrausch. . 



Berndt 



Dobson 



Dobson 



Place 



Swinemiinde 



Potsdam 



Seewalchen (Up. Austria) 



Mattsee (Salzburg) 



Munich 



Jachenau (Up. Bavaria) . 



Karasjok (Lapland) 



Freiburg (Switz.) 



Kalocza (Hungary) . 

 On the Danube, 

 Vienna. 



Davos 



Aibling (Bavaria) . . 



Moscow 



Seeham (Salzburg) . 



Amazon 



Kew 



Eskdalemuir. 



Period 



1904.... 

 1904 . . . . 

 1904 . . . . 

 1905.... 



1905 



1905 . . . . 



1904 



1904-05. 



1909. 

 1909. 



1907-10 



Summer 1906 . . 



1906-10 



Summer 1912-1.3 . 



1911-12. 



1911-12 



583 

 770 

 937 

 728 

 1103 

 1271 

 792 

 708 



1083 

 792 



198 

 1062 

 708 

 646 

 375 

 438 



358 



458 

 625 

 792 

 604 

 875 

 1625 

 687 

 521 



832 



708 



854 

 625 

 625 

 354 

 321 



183 



1.27 

 1.23 

 1.18 

 1.21 

 1.26 

 0.78 

 1.15 

 1.36 



1.30 

 1.12 



1.24 

 1.13 

 1 03 

 1.06 

 1.37 



1 96 



References 



Ergebnisse der Met. Beob. in Potsdam, 1902, p. 1,1905. 



Do. 

 Wien. Ber., vol. 113, p. 1433, 1904. 

 Wien. Ber., vol. 114, p. 1705, 1905. 

 Phys. Zeit., vol. 6, p. 614, 1905. 



Do. 

 PhU. Trans. R. Soc. A, vol. 205, p. 61, 1905. 

 Met. Zeit., vol. 23, p. 53 and 539, 1906; vol. 25, p. 9, 



1908. 

 Wien. Ber., vol. 118, p. 1625, 1909. 

 Wien. Ber., vol. 120, p. 139, 1911. 



Licht und Luft im Hochgebirge, Braunschweig, 1911. 



Phys. Zeit., vol. 10, p. 113, 1909. 



Met. Zeit., vol. 29, p. 557, 1912. 



Wien. Ber., vol. 123, 1914. 



Met. Zeit., vol. 31, p. 446, 1914. 



Geophysical Memoirs No. 7, vol. 1, p. 167, 1914. The 

 values given have, however, been corrected to corre- 

 spond to the value 4.8X10-'"; E. B. V. for the 

 plcctrnnio chiirge. 

 Do. 



