SCIENCE-SUPPLEMENT 



automatically recorded from one end of the spec- 

 trum to the other. The record takes the shape of 

 a curve which mounts to different heights with 

 reference to its base Une, and these lieights are 

 proportional to the heat in the various rays of 

 the spectrum. The absorption bands due to the 

 chemical elements in rthe sun, and those due to 

 some of the elements and compounds of gaseous 

 na1;ure in the earth's artmoaphere, are indicated as 

 depressions in this sinuous curve. In this way the 

 effects of the earth's atmosphere upon the sun 

 rays may be determined and allowed for, so that 

 the intensity and quality of the rays as (they 

 would be outside the atmosphere, on the moon, 

 for instance, where there is none, can be com- 

 puted. When this is done, the intensity of the 

 sun's heat freed from atmospheric influences is 

 found to be variable. ' ' 



The form of distribution of the solar spectrum 

 gives an indication of the temperature of the sun. 

 Just as the blacksmith's iron as he heats it be- 

 comes faintly glowing, then a brighter red, then 

 yellowish, then white hot, so the sipectra of the 

 srun and other stars depend for the arrangement 

 of the intensities of the different colors upon the 

 temperatures which prevail in these sources of 

 light. The -measurements of the Smithsonian 

 Institution indieate a temperature for the sun 

 aipproximating 0,000 degrees C. 



NO SCIENTIFIC BASIS FOR PREDICTING 

 CALIFORNIA QUAKE 



The fact that the earthquake zone in California 

 is analogous geologically to the devastated region 

 :in Chile has raised some apprehension here as to 

 the probability of a quake or tidal wave in Cali- 

 fornia. 



Since tlie disaster of 1906, considerable seien- 

 *ific research on tlie causes of the crust movements 

 on the west coast has been conducted which may 

 eventually lead to definite earthquake predictions. 



But Dr. H. 0. Wood, in charge of investiga- 

 tions for the Carnegie Institution of Washing- 

 ton, when seen at the Mount Wilson Observatory, 

 said : 



"There is no scientiifle basis for any estimate of 

 probability of an earthquake in California follow- 

 ing upon the recent siiock in Chile. No indica- 

 tions of any impendiug shock have been noted 

 here. Sometimes several great earthquakes have 

 occurred in places far distant from one another 

 ivithin a relatively short time interval so as to 

 suggest causal group occurrence but more com- 

 monly there is no such apparent grouping in the 

 occurrence of great shacks. ' ' 



About 150 niiles off the coast of California, 

 there is a sharp break in the ocean bottom that is 

 as steep ag the east slope of the Sierra Nevados, 

 according to Dr. William E. Bitter, director of 

 the Seripps Institution for Biol«gical Eeseareh, 

 who located it by extensive soundings when he 

 was on the oeeanographie expediition of the 

 Alhatross in 1904. It has been suggested that 

 this is a plane of weakness that might give rise 

 to an earthquake at sea. Such a crustal slip 

 would probably create a serious tidal wave such as 

 that which swept the Chilean eoast in the wake 

 of the recent shocks. 



But investigations into the history and folklore 

 of the country are reassuring. They indicate that 

 no tidal wave ever swept the California coast, ac- 

 cording to Dr. Bitter. There is not even a tra- 

 dition of sudden encroachment of the sea upon 

 the land. 



HOW CHILEAN QUAKE HAPPENED 



How Chile's death-dealing earthquake, wliich 

 shattered cities and engulfed their helpless inhab- 

 itants with tremendous tidal waves, originated at 

 soa off the coast of that country, is explained by 

 Dr. W. J. Humphreys, meteorological physicist of 

 the U. S. Weather Bureau, from the seismographio 

 records made by the earth's tremors at this point. 

 For four hours the pen of the highly sensitive 

 instrument drew the picture of the movements ia 

 the earth, which wrought such havoc among the 

 Ohilean towns in a few minutes. 



Earthquakes, Dr. Humphreys said, are pro- 

 duced by a sUpping or breaking of the crust of 

 the earth as a result of strains. These strains 

 may be caused by the shrinking of the interior of 

 the earth through temperature changes, changes 

 in loads due to rapid erosion taking material from 

 one place to another in the course of a few hun- 

 dred years, or from the tendency of higher land to 

 flow out to sea. 



From what is known of the present quake, it 

 seems to have been caused by higher land moving 

 out to sea. The actual break in the crust oc- 

 curred at some distance from shore, and this sud- 

 den change in the ocean floor at that point pro- 

 duced a tidal wave. As there were several such 

 waves, there must have been several faults or 

 breaks in the earth's crust at the sea bottom 

 which created the different huge billows in the 

 incompressible water. It is probable that this 

 crack extended for a hundred miles or more and 

 that the wave created was detected in the Philip- 

 X)iues or other distant Pacific points. 



Breaks, such as caused the shocks and waves 



