Explanatory Remarks and Observers 21 



is the result of seven determinations made during the interval 9 h l to ll h 3, local 

 mean time, inclusive"; 6 h l to 20 b 3(dv) is to be read "eye readings of the sus- 

 pended magnet were made regularly at short intervals from &l to 20 h 3, local 

 mean time." For observatories and other fixed stations, where observations were; 

 made frequently, it has appeared desirable to give only the mean values of the 

 magnetic elements as determined at approximately the same local mean times on 

 each of the days grouped in the date column (see entries for Watheroo Observa- 

 tory and footnote, p. 57). The local mean times are given according to civil 

 reckoning and are counted from midnight as zero hour continuously through 24 

 hours; 16 h , for example, means 4 o'clock p. m. 



The declination values, as also of inclination, are in general given in degrees, 

 minutes, and tenths of minute of arc. For instruments which are not regarded 

 as capable of yielding great accuracy only the nearest minute is given. The 

 tabulation of values of the horizontal intensity has already been explained above. 



The instruments used are shown in the columns "Mag'r" (magnetometer) 

 and "Dip Circle." When the number of an instrument in magnetometer column 

 is italicized, it means that a dip circle has been used in getting the declination 

 by means of the compass attachment, and that total instead of horizontal inten- 

 sity was observed. A designation in the column Dip Circle, e. g., 206.12, stands 

 for "Dip circle No. 206, needles Nos. 1 and 2"; 222.1256, for "Dip circle No. 

 222, needles Nos. 1, 2, 5, 6"; 171.12(78) for "Dip circle No. 171, needles Nos. 1 

 and 2 of No. 171 and 7 and 8 of another circle," as explained in Table 4, giving 

 "Inclination Corrections." 



OBSERVERS. 



In the last column of the Table of Results, the observer responsible for the 

 observations is shown by his initials. Those engaged from time to time in the 

 execution of the present work were as given in Table 5. 



When observations were made jointly by two observers, this fact is shown 

 by the combination of their last initials, as indicated in the latter part of Table 5. 



For the land observations secured by members of the ocean party the abbre- 

 viations C III, C IV, C V, and C VI have been used for the various cruises of 

 the Carnegie. Observers on the cruises for which this volume contains results 

 were as follows: 



C III: J. P. Ault, commander; with Observers H. M. W. Edmonds, H. F. Johnston, I. A. 

 Luke, and N. Meisenhelter. 



C IV: J. P. Ault, commander; with Observers H. M. W. Edmonds, H. F. Johnston (to 

 April 1916), I. A. Luke (to October 1916), H. E. Sawyer (from April to Novem- 

 ber 1916), N. Meisenhelter, F. C. Loring (to October 1916), B. Jones (from April 

 1916), A. D. Power (from November 1916), and L. L. Tanguy (from November 

 1916). 



CV: H. M. W. Edmonds, commander; with Observers A. D. Power, B. Jones, L. L. 

 Tanguy, J. M. McFadden, and W. E. Scott, 



C VI: J. P. Ault, commander; with Observers H. F. Johnston, R. Pemberton, A. Thomson, 

 H. R. Grummann, and R. R. Mills. 



