214 On the transverse Strength of Timber. 



named Langbargh, from its form, a name which it has imparted 

 to the whole wapentake*. 



This singular lidge is composed of blocks or masses, generally 

 oblong, and King across the vein, parallel to one another, in a 

 form approaching to that of basaltic pillars, yet without any re- 

 gularity of shape or size. The interstices are filled with a kind 

 of ferruginous earth, or decayed whinstone, and the blocks are 

 coated with a crust of the same colour : the recent fracture, 

 which is rough and granular, presents a dark blue colour, with a 

 number of small shining crystals. The stone is exceeding hard, 

 and is excellent metal for making roads, Mr. Bailey, in his Sur- 

 vey of Durham, (p. 32.) justly remarks, that it •' seems to have 

 been in a state of fusion when it filled up the fracture, as the seam 

 of coal, for some feet distance on each side, is turned into a 

 sooty substance, which becomes a cinder as the distance from the 

 whinstone increases, and bv degrees assumes the natural appear- 

 ance of coal with all its properties: which takes place about 50 

 yards from the whinstone." What impression it has marJe on the 

 aluminous schistus, which it traverses in our alum hills, has not 

 been ascertained : but in Langbargh quarry we see the south side 

 of its bed, against which it has leaned, appearing smooth and 

 firm, as though it had been baked, 



XXXVII, On the transverse Strength and Resilience of Timber., 

 By Mr. Thomas Tredgold. 



To Mr. Tilloch. 



Sir, — X HE growth of our own ship-timber has always been 

 considered to be of great importance to this country; but on ac- 

 count of the slow growth of the oak, the demand, it is probable, 

 will soon far exceed the produce of the British Islands: therefore, 

 the introduction of the larch, v.'hich has been very extensively 

 planted by a few patriotic individuals, is very justly esteemed an 

 object of national importance, as the rapid growth of the larch 

 far exceeds that of most of our native trees, and " it is remark- 

 ed," says Dr. Hunter, '* that those trees which have been planted 

 in the worst soils, and most exposed situations, have thriven the 

 bestf." 



The timber of the larch is durable; it does not burn readily, 



* The original name Langberg signifies Long-hill : the ancient name of 

 Rosebury was Ohtneberg or Hogtenberg = High-hill. The vvapentake 

 courts were formerly held at Langbargh, and the stewai'd still holds his 

 court, pro forma, beside Langbargh quarry. 



•f" Notes on Evelyn's Silva, i. 280. 



and 



