EVERYDAY SCIENCE 



CHAPTER I 

 THE OPEN SKY 



Go forth under the open sky and list 

 To Nature's teachings. BRYANT. 



The Sun. Our earth seems so large to us, when we 

 think of the time required for a trip around it, that we meas- 

 ure smaller things by com- 

 parison with it. But the 

 sun is so tremendous that 

 the earth is little more 

 than a dot compared with 

 it. To make a trip by 

 fast express from San 

 Francisco to New York 

 requires about four days, 

 and the average rate of 

 travel is about thirty 

 miles an hour. If such a 

 train could follow the line 

 of the earth's equator at 

 this steady rate, it could 

 complete the circuit of the 

 earth in a little less than 

 thirty-five days. But if 



MT. WILSON SOLAR OBSERVATORY, THE 



150-FooT TOWER TELESCOPE 



Probably the most effective instrument 



there is for studying the sun. 



it were possible to make 



a similar trip around the surface of the sun, more than 



ten years would be required for the journey. 



