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WILLIAM HERBERT HOBBS 



cruise over the Black Sea, Hecker has now so revised his figures 

 that they are no longer recognizable, and many of the excessive 

 values for Ag. for one reason or another have disappeared alto- 

 gether. 1 This is true, for example, for the third entry in the list 

 quoted in table III. Hecker's methods have been more sharply 

 challenged by Bauer 2 upon the ground that his instruments were 



TABLE III 



North Sea and British Channel 



* Author's interpolation. 



TABLE IV 

 Between Cape Verde Islands and Equatorial Ridge 



* Author's interpolation. 



not sufficiently standardized and checked during the work, and 

 because his methods were in other respects open to criticism. In 

 his first paper Bauer has sought further to discredit Hecker's 

 corrected figures upon the ground that the values for Ag. vary 

 more widely from Hay ford's than did those of the first series. This 

 point of view is interesting as indicating that local anomalies in 



1 O. Hecker, "Bestimmung der Schwerkraft auf dem schwarzen Meere sowie 

 neue Ausgleichung der Schwerkraftmessungen auf dem atlantischen, indischen und 

 groszen Ozeane," Verofentl. d. Zentralbureaus d. Intemationalcn Erdmessung (N.F.), 

 No. 20 (Berlin, 1910), pp. 1-160, 4 pis. (especially pp. 151-60). 



2 L. A. Bauer, "On gravity determinations," etc., Am. Jour. Sci. (4), XXXI 

 (19 11), 1-18. See also Hecker's remarks on "Ocean Gravity Observations" (a reply 

 to Hecker), ibid., XXXIII (191 2), 245-48. 



