It is referred the part of the tree tree trunk to use as materials of various uses to the wood . Because a tree is a creature, a property is different, and there is not the same thing by one of them with the tree of the same kind either, and I am handled, and there is a case to need a special device. The time to the winter is done with an optimum of the felling in the summer in Japan belonging to rain-related temperate regions from the autumn when the metabolism of the tree falls, and, by the season, as for the thing which I felled in this time, it is it in strong wood to sepsis and a harmful insect.