DO \OLCAXIC EXPLOSIONS AFFECT OUR CLIMATE? 



181 



j\Ian escaped the injuries received by 

 the other animals by seeking sheher. 

 Many of the people reported severe 

 headaches, pains in the throat and lungs, 

 and sore eyes while the dust and fumes 

 were in the air. Two or three people in 

 Kodiak died during the eruption, but 

 their deaths are considered as being 

 merely hastened by exposure and by 

 breathing the dust and as not due pri- 

 marily to the eruption. 



]\Ian was indirectly affected by the 

 eruption through the injury to other ani- 

 mal life and to vegetation. The scarcity 

 of salmon during the summer of 1912, 

 the injury to crops and grass, and the 

 destruction of srame and fur animals 



must all be counted as indirect, but none 

 the less serious, injuries to man. The ef- 

 fect on the salmon, through the probably 

 complete filling of all the smaller lake's 

 by the ash, which will for years work 

 down the streams and hillsides into them, 

 and through the possibly permatient de- 

 struction of the spawning grounds, is 

 probably the most serious of these in- 

 juries. 



\'egetation will be affected only tem- 

 porarily, the soil will probably be im- 

 proved, and the people can feel assured 

 that not in many years, and possibly not 

 in centuries, can the volcano accumulate 

 enough force to cause another eruption 

 of this character. 



DO VOLCANIC EXPLOSIONS AFFECT OUR 



CLIMATE? 



By C. G. Abbot 

 Director AsTRoriivsiCAL Odskrvatory, Smithsonian Institution* 



J nth Photographs by George C. Martin 



IX THE month of June. 1912, I was 

 engaged in making measurements 

 at Bassour, Algeria, on the quantity 

 of heat coming to the earth from the 

 sun. At the same time my colleague, Mr. 

 F. E. Fowle, was engaged in making 

 similar measurements at Alount Wilson, 

 in California. Recent work of the As- 

 trophysical Observatory had strongly in- 

 dicated that the sun is a variable star. 

 The fluctuations in the amount of the 

 solar radiation seemed to be of variable 

 magnitudes, seldom exceeding 5 per 

 cent, and occurring in irregular periods 

 of from 5 to 10 days. 



The work on which this conclusion 

 was based had been done at Mount Wil- 

 son, in California, and it was not impos- 

 sible that local atmospheric conditions 

 may have had such an influence there 

 that the observed changes might possi- 

 bly be of atmospheric origin. To ex- 

 clude this possibility it was necessary to 

 show that the same results would be 

 reached by simultaneous observations at 

 another station so remote from Mount 



* Published by permission of the Secretary 

 of the Smithsonian Institution. 



Wilson that the local circumstances 

 would be entirely different. 



Hence it was that an expedition occu- 

 pied the station in Algeria in 1911. and 

 again in 1912. As we shall not have 

 occasion to refer again to the main pur- 

 pose of the expedition, it will suffice to 

 say here that, so far as yet reduced, 

 high values of solar radiation obtained 

 in Algeria coincide in time with high 

 values obtained at Mount Wilson, and 

 vice versa : so that the results seem to 

 strongly confirm the supposed solar va- 

 riation. 



DUST FROM ALASKA OBSERVKO IN AI.f.ERIA 



While observing on June 19, 1912. I 

 noted streaks resembling smoke lying 

 along the horizon, as if there were a 

 forest fire in the neighborhood of the 

 station. These appearances continued, 

 and were soon joined by others more 

 noticeable. After a day or two we 

 began to see peculiar mottled figures 

 like those of the mackerel sky. although 

 absolutely no clouds were present. The 

 phenomenon became so marked that we 

 ceased entirelv our observations of the 



