CHAP. XI.] WINTER FELLING. 115 



viewed under the commercial aspect, it is not lilsely to be 

 disregarded. 



The quantity of tannin contained in the bark of the 

 Oak, as ascertained by Sir Humphry Davy, varies as 

 follows, viz. : In Coppice Oak it is 32 ; middle sized, 29; 

 and Oak cut in the autumn, 21 per cent. 



The timber and bark merchants variously estimate 

 the quantity of bark proportionate to the contents of the 

 timber; and no doubt there is a very considerable 

 difference in the weight afforded by trees of equal 

 ages, whether grown in forests or in open situations, 

 Mr. Monteith states, in his " Planter's Guide," that— 



An Oak 40 years old yields, for every cubic 



foot of timber 9 lbs. to 12 lbs. of bark. 



And if 80 to 100 years old yields, for every 



cubic foot of timber 10 lbs. to 16 lbs. ,, 



The question of the propriety of felling in the winter in 

 preference to any other season is of considerable import- 

 ance, and its bearing upon the durability or otherwise of 

 the timber may be gathered from the following par- 

 ticulars, taken from a " Treatise on Dry Rot," by 

 Ambrose Bowden. He states that — 



" The Sovereign of thi Seas, built at Woolwich in 

 1635, was constructed of timber barked in the spring 

 and felled in the succeeding winter, a strong conviction 

 existing that such timber was superior to any other in 

 point of durability. Forty-seven years later this ship 

 was pulled to pieces and rebuilt, and the greater part of 

 the materials were found to be in sufficiently good con- 

 dition for re-employment. 



" The Royal William, built at Portsmouth in 17 15 tp 

 17 19, after being slightly repaired at three different 

 times, was finally taken to pieces in August, 181 3, after 

 a service of ninety-four years. The extreme durability 



I 2 



