882 



SCIENCE 



[N. S. Vol. XXXIX. No. 1015 



quented and even the more dangerous regions, and 

 j'et, in spite of the great distances travelled and 

 all the excessive difficulties encountered, the entire 

 survey has thus far been made without the occur- 

 rence of a single fatal accident. 



Isostacy and the Size and Shape of the Earth: 



"William Bowie. 



The determination of the size and shape of the 

 earth would be a simple matter if its geoid or sea- 

 level surface formed a geometrical figure, but as it 

 does not the actual problem is a difficult one. 

 These deviations, it was shown, are due to differ- 

 ences in the vertical distribution of mass in ad- 

 jacent isostatic regions. When corrections for the 

 effects of topography and isostatic compensation 

 are applied to the astronomically observed posi- 

 tions the deviation of the geoid from the spheroid 

 surface is largely eliminated. 



The shape but not the size of the earth may be 

 determined from the observed values of the force 

 of gravity at stations widely separated in latitude. 

 Here again a correction for topography and iso- 

 static compensation is necessary for the best re- 

 sults. Absolute values of gravity can be obtained 

 only "with a long series of observations, and there- 

 fore nearly all gravity determinations are made 

 by the relative method. Those of the Coast and 

 Geodetic Survey are based on the absolute value at 

 Potsdam. 



Investigations made by the U. S. Coast and 

 Geodetic Survey during recent years show that the 

 area of the United States, taken as a whole, is 

 in a state of perfect isostacy, and that areas of 

 limited extent deviate only slightly from that 

 state. The paper will later appear in full. 



Seismology: Otto Klotz. 



The most improved seismological apparatus, the 

 data obtained by them and the conclusions log- 

 ically deduced from this data were all discussed 

 at some length. A full and interesting account, 

 together with many illustrations, was given of a 

 recent installation of seismological apparatus that 

 registers in magnified form even those small vi- 

 brations of the earth 's crust caused by the passage 

 of ocean waves. 



The Factors of Climatic Control: W. J. Hum- 

 phreys. 



It was explained that such things as land ele- 

 vation, oceanic circulation and volcanic dust in the 

 high atmosphere are among the most important 

 factors of climatic control, assuming of course 

 approximate constancy of atmospheric composi- 

 tion and solar radiation. 



Both the direct or primary and the indirect or 

 secondary effects of each of these factors were 

 explained in some detail and illustrated by statis- 

 tical curves. 



It is expected that the paper will later appear 

 in full. 



There was also one joint meeting with Section 

 C — Chemistry, at which the following papers were 

 presented : 



Geoehemical Besea^ch: John Johxston. 



A general account of some of the main lines of 

 geoehemical work which are now being pursued 

 in the geophysical laboratory of the Carnegie In- 

 stitution. 



The Ternary System Lime- Alumina-Silica: G. A. 



Eankin. 



The author discussed the results of an extended 

 investigation of this system, which is important 

 from a geological standpoint as well as from the 

 fact that these three oxides are the essential in- 

 gredients in the manufacture of portland cement 

 clinker. The fields of stability of all the sub- 

 stances which may be encountered in this system 

 have now been determined satisfactorily; so that 

 it is now possible to state precisely what happens 

 when any mixture of the above three oxides is 

 heated, and hence incidentally to specify the es- 

 sential constituents of portland cement clinker. 

 W. J. Humphreys, 

 Secretary of Section B 



SOCIETIES AND ACADEMIES 



ACADEMY OP SCIENCES OP ST. LOUIS 



At a meeting held June 1, Professor Nipher gave 

 a brief account of a new method of decomposing 

 water. 



A continuous discharge from electrodes in sepa- 

 rate beakers was made to pass through a capillary 

 tube, forming a siphon connecting the water in the 

 two beakers, water was decomposed at the elec- 

 trodes and within the siphon. More than 50 times 

 as much explosive gas was discharged from the 

 siphon as was collected in the tubes around the 

 electrodes. Distilled water which had been 

 freshly boiled was used. 



A full account of this result will be given in a 

 volume now in the hands of the publisher, which 

 will give a full account of the results of Professor 

 Nipher 's experimental work during the last five 

 years. 



C. H. Danporth, 



Secretary 



