104 LIFE OF A TREE. 
since in the form of wood, and of living 
plants. Now sometimes persons have found in 
beds of coal pieces, which, though quite con- 
verted into coal, still exhibit the marks of the 
rings of which we have been speaking. These 
persons, knowing that each ring was the sign of 
a year in age, have counted them up, and have 
thus been able to tell how many years old the 
tree was before it was changed into coal. And 
not only so, but as the rings are wider or nar- 
rower apart, according as the seasons are fine and 
favourable for the formation of wood, or as they 
are cold and unfavourable to that process, they 
have been able to learn also, almost, we might 
say, What kind of weather it was at the particular 
period when these very trees were alive, which 
must have been at least many centuries ago! 
This gives us a good illustration of the delight- 
ful and interesting information, which even a 
moderate knowledge of any science will enable 
us to enjoy. Henceforward, when the reader 
passes a tree felled by the woodman, and lying 
by the wayside, let him spend a few minutes 
over it in counting up the rings, which he will 
readily detect at the cut end; and he may have 
