“It would be much simpler if we could do it that way, but unfortunately the distance is not the same in any two different kinds of trees, or even in the same tree,” replied Cecil. “There are many things that affect the growth of trees. For instance, if a young tree is crowded for light and room, the rings will be very close together. Then if the surrounding trees dies or are cut down and the crowded condition relieved, the young tree will grow much faster and the distance between two rings may be the same as that between seven or eight rings during the period of slow growth. Two trees growing side by side, although they may be of the same species, may have entirely differently spaced annual rings.”