252 THE STORY-BOOK OF SCIENCE 



ing the earth with light and heat, ripening the yel- 

 low harvest, giving perfume to the flowers, taste to 

 fruit, life to every creature. 



Then Uncle Paul, in the shade of the juniper- 

 trees, began his talk. 



"What is the sun? Is it large, is it very far 

 away? That, my children, is what I should now 

 like to teach you. 



"To measure the distance from one point to an- 

 other, you know of only one means: that of laying 

 off, as many times as it will go, the unit of length, 

 the meter, from one end to the other of the dis- 

 tance to be measured. But science has methods 

 adapted to the measuring of distances that one can- 

 not travel in person; it tells us what must be done 

 to find the height of a tower or mountain, without 

 going to the top, without even approaching the base. 

 They are methods of the same kind as are employed 

 to calculate the distance that separates us from 

 the sun. The result of the astronomer's calcula- 

 tions is that we are distant from the sun 38 millions 

 of leagues of 4000 meters each. This distance is 

 equivalent to 3800 times the circumference of the 

 earth. I told you that, to make the tour of the ter- 

 restrial globe, a man, a good walker, capable of walk- 

 ing ten leagues a day, would take about three years. 

 He would need, then, nearly twelve thousand years to 

 go from the earth to the sun, supposing that the 

 journey were possible. The longest human life is in- 

 comparably too short for a journey of this length 

 ever to be accomplished by one person ; and a hun- 

 dred generations of a hundred years each, succeed- 



