324? Mr. J. S. Enys's Remarks on the Granite found 



Inches. Inches. Sq. In. Power. 



The capping wayl^ . |2 Wedges, 



measured J J \\ Ripper. 



The tough ditto 24? by 15 = 360 3. ..3 Wedges. 



This, as far as one trial can do so, more than proves the 

 stone-cutter's assertion; — the cleaver likewise added that the 

 tough way was struck rather harder than the other. The 

 cleaving can be effected on any diagonal line, but the fracture 

 is untrue ; it is almost invariably true both on the capping 

 and cleaving lines, though less on the tough way. 



In cleaving granite two varieties of gear are in use, Wedges 

 and Cues, — the latter so called from the ox-shoes, which were 

 first used for the purpose; and Rippers and Feathers. The 

 ripper is sometimes called a Tearer ; it is only a tapered bar of 

 iron, in fact a circular wedge ; it is used in deep holes formed 

 by a borer or jumper ; the last is well known in quarries, the 

 former is beat by a man with a sledge-hammer, and turned in 

 the hole by a boy who holds it. The wedge is placed in a groove 

 cut about three inches deep. The cues and feathers are thin 

 slips of iron acting in a similar manner, and are respectively 

 placed against the sides of the groove or hole when the wedge 

 or ripper is placed between them, and struck down with a 

 sledge-hammer, generally of 30 pounds weight. One ripper 

 is considered more than equivalent in pow r er to three wedges : 

 these last are chiefly used for cleaving small blocks of 2 or 3 

 feet. The holes are bored about 1 foot apart, so that a large 

 rock requires a great number of rippers, which are struck alter- 

 nately, and slide down without any great friction between the 

 feathers, and cause a pressure sufficient to cleave down 20 or 

 25 feet in depth. For deep cuts of 24 feet or even less, it is most 

 usual to drive down the rippers in the evening until the iron 

 begins to feel warm, and leave them for the night; in the en- 

 suing morning a fine hair-line fracture will be found, which is 

 easily increased ; whereas should it have been attempted to 

 drive the rippers at once, the iron would be destroyed before 

 the rock would be split. 



On the other side of the Channel, wedges only were observed 

 to be in use : perhaps this may account for the small size of 

 the granite blocks used in the construction of the docks at 

 Brest. Powder has been sometimes used near Penryn, par- 

 ticularly in capping, and 1 or 1 \ pound of it has been known 

 in a 9-feet hole to have effected a true fracture 18 feet long 

 by 9 feet wide. 



It would be advantageous to the cleavers, or under-con- 

 tractors for the supply of granite, if engineers, architects and 





