ON THE DETERMIKATION OF GRAVITY AT SEA. 



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Fig. 3. 



Types of records obtained with one of Hecker's self-recording enclosed barometers 

 on four different days, showing approximate time-scale and the engraved fiducial 

 lines, which are 2'84 mm. apart on the barometer tube. Sept. 12 and Oct. 8 were 

 very rough days. The reproductions represent positives, hence the black portion 

 represents the mercury in the tube. The depths are in fathoms. 



1919. 



