Of the oak. 



The Nature of its Produdtion ; tbe differe^it Degrees of Goodnefs hi 

 Oak Timber; and tie Caufes of that Difference. The Autlor's 

 Opinion as to tie proper Seafon for felling Timber. 



J.N order to form a true judgment of the nature of this Tree, and 

 the better to comprehend the following defcriptions of the * veflels, 

 which compofe the lame, let us firil attend to Plate I- ^g. i -}-, 

 BCD, and imagine it to reprefent the furface of an Oak when 

 cut tranfverfely or acrofs the middle, on which furface eighteen 

 circles appear ; which circles are the clear and undoubted marks of 

 eighteen years growth, the tree being increafed every year by the 

 addition of one circle, (and in the latter of thofc years the circles are 

 the largeft, though not all of equal magnitude, but in proportion 

 to the fertility of each year.) The fmall portion of this wood, 

 defcribed in the next figure is marked in the fixteenth circle by the 

 letter E. Farther, fuppofmg the tree to be fawn acrofs, as above- 

 mentioned, and afterwards planed or polifiied, we fliall obferve 

 throughout the furface, fireaks or creafes, reaching from the centre 

 A, to the circumference B, and thefe are veilels conveying the nu- 



* Cy the word veflch, are to be undciflood, throughout this Work, fmall tubes, or pipes, 

 ■running in different diredlions, in tlie fubjedts treated of. 



f This figure, which in the original, is only fo many circles, the Tranflator has caufed to 

 be engraved from a piece of Oak of the fize here dcfci ibcd ; at F is reprefcnted a knot which 

 was in the tret. 



