SCIENCE 



[N. S. Vol. XXXII. No. 833 



On the " First Cruise of the Carnegie in the 

 North Atlantic, which began at Brooklyn in Sep- 

 tember, 1909, and was closed at the same point 

 in February of this year, determinations of the 

 boiling point of pure water were made with the 

 view of obtaining the necessary corrections to the 

 aneroids aboard. Careful scrutiny of these ob- 

 servations gave the impression that with proper 

 refinement in instrumental equipment and in 

 method of observation, it would be possible to ob- 

 tain data from which ocean gravity anomalies 

 might be determined by the same method employed 

 by Dr. Hecker in his cruises of 1901, 1904 and 

 1909 — the so-called boiling point barometer 

 method. 



In order to determine wherein refinement was 

 necessary and what the chief sources of error were, 

 and their relative quantitative effects, the speaker 

 made a careful review of previous ocean gravity 

 observations. As a result of Ms combined study 

 of the existing data and of the recent observations 

 on the Carnegie he was led to the following con- 

 clusions on Becker's ocean gravity work: 



1. No wholly satisfactory measure of the abso- 

 lute accuracy of the existing ocean gravity results 

 can be secured by a mere perusal of the publica- 

 tions. If an independent examination is made and 

 such checks applied as are possible, and when all 

 sources of error are considered, it will not be sur- 

 prising if it be found that many of the most re- 

 cently published results are in error by an amount 

 approximating to 0.1 cm. or about l/10,000th part 

 of g. In view of the pioneer nature of the work, 

 opportunities presented for repeating observa- 

 tions, under different conditions, over regions 

 previously traversed, should have been more fully 

 embraced than was done. 



2. One of the chief sources of error is to be 

 ascribed to inconstancy of the corrections of the 

 boiling point thermometers caused by their con- 

 tinued and protracted use; the error thus arising 

 may at times transcend in importance all other 

 ones. Not sufficient attention was paid to purely 

 instrumental changes and corrections. Thus, for 

 example, corrections for the boiling point ther- 

 mometers of the Atlantic Ocean work of 1901 were 

 used practically unaltered throughout the subse- 

 quent cruises of 1904 and 1909 — after having been 

 once supplied by the Physikalische Reichsanstalt, 

 the corrections were never again redetermined. 

 The belief that such purely instrumental changes 

 would fully be taken accoimt of in the adjustment 

 is shown to be fallacious. 



3. A source of error not considered is that 

 due to possible imperfections of the vapor tension 

 tables which must be used to convert boiling point 

 temperatures into corresponding atmospheric 

 pressures. An examination of the existing tables 

 for the interval here under consideration, about 

 99° to 101° C, indicates that the errors of even 

 the latest tables may at times be sufficient to 

 cause an error in g of 0.1 cm. This error is not 

 a constant one but varies with the boiling point 

 temperatures; it is, hence, not wholly eliminated 

 even in differential results. 



4. Insufficient evidence has been given to prove 

 that, in the reduction of the observations, it is 

 best to omit those made on board vessels at an- 

 chor. A method of adjustment which already 

 assumes practically what is to be proved, and 

 which necessitates the rejection of data secured 

 under supposedly the best conditions, weakening 

 thereby the connecting link between the ocean 

 results and the shore pendulum stations, can 

 hardly be regarded as the best possible one. In- 

 stead some logical method of observation and of 

 adjustment must be striven for which will take 

 advantage to the fullest possible extent of the 

 shore and harbor results. 



5. The problem of sufiiciently reliable ocean 

 gravity results still awaits solution. 



(The foregoing abstract was prepared by the 

 author. ) 



R. L. Fabis, 

 Secretary 



THE AMEEICAN CHEMICAL SOCIETY 

 NEW TOBK SECTION 



The second regular meeting of the session of 

 1910-11 was held on November 11. 



The following papers were presented: 



" The Electron Conception of Valence," K. G. 

 Falk and J. M. Nelson. 



" The Influence of Vapors on the Surface Ten- 

 sion of Mercury," Morris Loeb and S. E. Morey. 



" Electrochemical Oxidation of some Hydrazine 

 Salts " and " The Electrochemical Corrosion of 

 some Metals in Sodium Trinitride," J. W. Tun'en- 

 tine. 



Following these papers, Mr. Henry G. Pearson, - 

 editor of the India Bubber World, gave an illus- 

 trated lecture on " The Rubber Country of the 

 Amazon." 



C. M. Joyce, 



Secretary 



