THINNING AND PRUNING. 33 
young trees grow more rapidly than old ones, they are more 
valuable as fuel. Round wood of oak or maple gives more heat 
than that which is so large as to require to be split. This fact 
shows the wastefulness of burning on the ground the under- 
growth and the trimmings, in clearing for cultivation or cut- 
ting for cord wood. Heart wood is heaviest, and the weight 
diminishes on proceeding outwards to the surface or upwards 
to the top of the tree, but much less in old trees than in young 
growing ones. ‘The sap. wood of oak was found by Decandolle 
to fall short of the heart wood in weight, in the proportion of 
6 to 7. 
It has long been known that summer or early autumn 
is the season most favorable for the felling of timber, where 
the object is strength and durability. One reason why timber 
has not usually been cut at that season is, that most of those 
who fell trees are at that season occupied with their farming. 
The felling of trees is their winter employment. Nearly a 
quarter of a century ago, Timothy Pickering showed by ex- 
periments which he adduced, and by sound reasoning, that 
summer is better than winter for this purpose.* A writer 
in the N. BE. Farmer,t who “‘has wrought more timber than 
most men, and for more uses than any he knows of,” says, he 
has found soft maple, cut in September, three times more lasting 
than ash or walnut cut in winter; that he has found the sap- 
wood of oak, cut in February and March, partly decayed in 
September, and the sap-wood of timber cut in May and June, 
decayed in a year, while the sap-wood of trees felled in Septem- 
ber was perfectly bright and sound after two years; and that, 
from many observations he has made, he is satisfied that Sep- 
tember is the best time for felling trees; and thatif the tree be 
disbarked in June, and allowed to stand till September, the tim- 
ber will be stronger and more durable. He has seen this proved 
with regard to elm, walnut (hickory,) and maple, which are 
considered the most perishable of the trees used for timber. 
* See Vol. I., No. 3, for August, 1822, of the N. E. Farmer. 
+ Mr. Phineas Stevens, of Andover. Ibid, II., 370. 
5 
