Natural History. 4W 



and one hundred and thirty years, and then furnish a lar^e (juan- 

 tlty of buildinj^ wood. The duration of the life of the elm de})ends 

 much upon the soil ; in a dry soil it becomes aajed, as it were, in 

 forty, tiily, or sixty years. Elms which have been lopped live for 

 a shorter period than the others. Those which grow by the road 

 side, or in thin plantations, may he cut when seventy ©r eighty years 

 of age. In general, the increase of hard woods, as the oak and 

 the elm, is small at first; it successively augments until the twentieth 

 or twenty-fifth year, is then uniform until the age of sixty to eighty 

 years, after which it sensibly diminishes. 



For these and other reasons, it is important that trees should be 

 cut down when they are at their mature state, and not simply when 

 they undergo no further increase. When the period has arrived 

 after which the increase of the tree would be less and less from 

 year to year, then the tree should be felled, for no advantage ac- 

 crues from its remaining longer in the ground. The indications 

 of tlie mature state of a tree are by no means so evident as those of 

 decay, but still certain signs of these states, as well a9 of the vigor- 

 ous condition of the tree, may always be observed. 



I. Signs announcing the vigour of a tree. — The branches, espe- 

 cially towards the top, are vigorous : the annual shoots strong and 

 long ; the leaves green, vigorous and thick, principally at the sum- 

 mit, and falling late in autumn ; the bark is clear, fine, united, and 

 nearly of the same colour from the foot to the large branches. If 

 at the bottom of the veins or divisions of the thick bark there ap- 

 pear smaller divisions which follow from below upwards in the direc- 

 tion of the fibres, and live bark be observed at the bottom of these 

 divisions, it is an indication that the tree is very vigorous and 

 rapidly increasing in size. If some of the lower branches stifled 

 by the others are yellow, languishing, and even dead, this is an 

 accidental effect, and is no proof of the languor of the tree. Finally, 

 it is a sign of vigour when branches are seen at the summit of the 

 tree rising above and being much longer than the others ; but it is 

 to be observed that all trees with round heads do not throw out 

 branches with equal force. 



II. Signs which indicate that the tree is mature. — Generally the 

 head of the tree is rounded; the shoots diminish in length each 

 year, and the furthest shoots add to the length of the branches only 

 by the length of the bud ; the leaves are put forth early in spring 

 and become yellow in autumn before those of vigorous trees, and 

 at this time the lower leaves are greener than the upper. The 

 branches incline towards the horizon, and form angles sometimes 

 of sixty or seventy degrees. These apparent signs, and the thin- 

 ness of the layer deposited by the sap, indicate that the tree makes 

 but small additions to itself, and now it should be cut down. The 

 nature of the earth should be examined, as well also as the kind of 

 tree, to enable a judgment whether the tree should be left to in- 



