34 CONVERSATIONS ON THE 



and their roots have plenty of room to spread, 

 as in England, where forests are scarce, and 

 the trees stand a great way apart ; in our 

 forests they grow close together, and therefore 

 we do not often see such huge fellows." 



" Is there no way of telling how old an oak 

 is, Uncle Philip ?" 



" Not till it is cut down ; then if you look 

 at the end, you will find a number of circles, 

 one within the other, from the bark to the 

 centre ; each of these circles counts for a year, 

 and oaks have been felled in which three and 

 even four hundred of these rings have been 

 counted." 



" What makes the circles, Uncle Philip ? do 

 you know?" 



" I can tell you what men who have studied 

 the nature of trees say about it : they tell us 

 that the sap-vessels, which lie just under the 

 bark, are soft and spongy in the summer, and 

 harden and get to be firm wood in the winter ; 

 when spring comes again, fresh sap rises in 

 another circle of vessels, pushing the bark 

 outwards ; and this in turn hardens again in 

 the winter, and so it goes on year after year, 

 forming new circles until the tree dies. And 

 now, boys, I believe I have told you enough 



