20 SYLVA BRITANNICA. 



measure, some inches. Upon the whole, this bears 

 every mark of having been a short-stemmed, 

 branchy tree, of the first magnitude ; spreading its 

 arms in all directions round it. Its aperture is a 

 small, ill-formed gothic arch, hewn out, or enlarged 

 with an axe, and the bark now curls over the 

 wound a sure sign that it continues growing : and 

 hence it is evident, that the hollow oaks of enormous 

 size recorded by antiquaries, did not obtain such 

 bulk whilst sound ; for the shell increases when the 

 substance is no more. The blea, and the inner 

 bark, receive annual tributes of nutritious particles, 

 from the sap, in its progress to the leaves ; and from 

 thence acquire a power of extending the outer bark, 

 and increasing its circumference slowly. Thus a 

 tree, which at three hundred years old was sound, 

 and five feet in diameter, like the Langley Oak, 

 would, if left to perish gradually, in its thousandth 

 year become a shell of ten feet diameter." 



"Hence," says Mr. Rooke, "we find by this 

 curious investigation of the growth of Oaks, that a 

 tree of about thirty feet in circumference may be 

 supposed to have attained the age of a thousand 

 years. Upon this calculation we may conclude, 

 that the Great Salcey Forest Oak, which is only 

 within two inches of forty-seven feet in circum- 

 ference, cannot be less than fifteen hundred years 

 old." It is equally probable that it should be more. 

 Mr. Marsham calculated the Bentley Oak to be 



