L. A. Bauer — Gravity Determinations at Sea. 13 



even for the same ocean, e.g., the Atlantic, it would 

 not be possible to compare directly gravity anomalies 

 between New York and Hamburg, with Hecker's between 

 Hamburg, Rio de Janeiro and Lisbon. He does not 

 explain completely bow he actually connected ocean results 

 with pendulum stations ; for example, how he distributed the 

 correction from one land station to another. Why he did not 

 refer his Atlantic Ocean results likewise to his pendulum 

 stations, e.g., at Rio de Janeiro and Lisbon, he does not say. 

 All this confusion has come about because of Hecker's method 

 of adjustment, as already explained, whereby he discards the 

 shore and port boiling-point observations ah initio and gets his 

 unknown coefficients from a least-square adjustment of ocean 

 observations. Having done that, he finds that the port 

 observations computed with these coefficients give results not 

 only very discordant among themselves but also with the 

 pendulum observations. He then has the difficult problem of 

 connecting his ocean results with land pendulum stations by 

 means of more or less discordant port and shallow water 

 stations. 



Tables I and II were drawn up from the figures in Hecker's 

 1910 publication ; a plus sign means that g at the place in ques- 

 tion is greater than it would be did the local disturbing cause 

 not exist, and a minus sign means, of course, the reverse. It 

 must be recalled that the tabidated Ar/'s are those as derived 

 from Hecker's adjustments ; if we may assume them correct, a 

 mere glance shows at once that the disturbances in g are, in 

 general, larger over the oceans than usually observed on land. 

 Table I would show that the difference in Ag for two oceanic 

 points may reach - 4 and even - 67 cm . 



Table I.— The Average, the Maximum, and the Minimum Values of 

 Gravity Disturbances as Shown by Hecker's Ocean Observations. 



(Eevised figures 1910.) 



Route 



A 



OR 



zo 



Agr 





Average 



Maxi'um 



Mini'um 



Range 



Hamburg — Rio de Janeiro 



Rio de Janeiro — Lisbon 



Spain — Suez — Colombo 



Colombo — Sydney . . 



Sydney — Honolulu— San Fran- 

 cisco 



1901 

 1901 

 1904 

 1904 



1904 



1904 

 1909 



47 

 35 

 33 



28 



41 



33 

 15 



cm 



±0-048 



56 



83 



61 



106 



54 

 31 



cm 

 + 0-172 

 + 0-142 

 + 0-289 

 + 0-214 



+ 0-393 



+ 0-310 

 + 0-079 



cm 

 -0095 

 -0123 

 -0-106 

 -0106 



-0-273 



-0-067 

 -0-052 



em 

 0-267 

 265 

 395 

 0-320 



666 



San Francisco — Honolulu — Yo- 

 kohama 



Black Sea (Odessa — Batum) 



0-377 

 0-131 



Entire Work, 1901—1909 





232 



±0-066 



+ 0-393 



-0273 



0-666 



