THE STORY OF NINETEENTH-CENTURY SCIENCE 



had taken place within historic times, it was clear that 

 some other explanation must be sought. 



Dr. Mayer himself hit upon what seemed a tenable 

 solution at the very outset. Starting from the observed 

 fact that myriads of tiny meteorites are hurled into the 

 earth's atmosphere daily, he argued that the sun must 

 receive these visitants in really enormous quantities 

 sufficient, probably, to maintain his temperature at the 

 observed limits. There was nothing at all unreasonable 

 about this assumption, for the amount of energy in a 

 swiftly moving body capable of being transformed into 

 heat if the body be arrested is relatively enormous. Thus 

 it is calculated that a pound of coal dropped into the sun 

 from the mathematician's favorite starting-point, infin- 

 ity, would produce some six thousand times the heat it 

 could engender if merely burned at the sun's surface. 

 In other words, if a little over two pounds of material 

 from infinity were to fall into each square yard of the 

 sun's surface each hour, his observed heat would be ac- 

 counted for; whereas almost seven tons per square yard 

 of stationary fuel would be required each hour to produce 

 the same effect. 



In view of the pelting which our little earth receives, 

 it seemed not an excessive requisition upon the meteoric 

 supply to suppose that the requisite amount of matter 

 may fall into the sun, and for a time this explanation of 

 his incandescence was pretty generally accepted. But 

 soon astronomers began to make calculations as to the 

 amount of matter which this assumption added to our 

 solar system, particularly as it aggregated near the sun 

 in the converging radii, and then it was clear that no 

 such mass of matter could be there without interfering 

 demonstrably with the observed course of the interior 



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