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. E. Farmer,! 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 that if 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. 

 t Mr. Phineas Stevens, of Andover. Ibid, II., 370. 



5 



