BUILDING AND ORNAMENTAL STONES. 313 



blows by heavy sledge-haniiners in the hands of the quarrymen 

 until the rock falls apart. This process will be made plain by refer- 

 ence to Plate III. In some of the quarries of softer sandstone no ma- 

 chines at all are used, the channeling being done entirely with picks 

 and the stone forced out by means of iron bars alone, or split out with 

 plug and feather. To allow of this, hovA'ever, the stone must be eveuly 

 and thinly bedded, and the dilferent sheets adhere to one another 

 with but slight tenacity, as is the case with certain of the New York 

 *' blnestones " and Berea grits of Ohio. In the New York quarries the 

 vertical joints are said to be so numerous as to practically do away with 

 the uecessity of channeling.* 



Powder is still largely used in most of the smaller quarries^ and in 

 all those of granite rock for throwing otf large masses. If properly 

 used with these harder varieties, it is doubtful if any serious harm re- 

 sults, but in the quarrying of marble and other soft stones, its use can not 

 be too strongly condemned. As suggested by Sperrt the rapid disinte- 

 gration of the Carrara marble is no doubt caused in part by the in- 

 cipient fractures induced through the crude methods of quarrying em- 

 ployed. Excepting when, as in the case of granite, no other means can 

 be employed, explosives of all kinds are to be avoided. When neces- 

 sary, they should be used in a lewis hole, whereby direction may be 

 given to the force of the discharge and the shock distributed over large 

 surfaces. 



(f)) CUTTING AND DRESSING STONE. 



In cutting and dressing stone the same slow hand processes that were 

 in vogue hundreds of years ago are still largely employed. There have 

 been, it is true, many machines invented for this i)urpose, but the ma- 

 jority of them are far from satisfactory in their working qualities, or 

 the cost of running them is so great that they can be used only by the 

 larger and wealthier firms. After a large mass has been split from the 

 quarry bed it is broken into blocks of the required size and shape by 

 means of wedges. A series of holes, three-fourths of an inch in diam- 

 eter and a few inches deep, is drilled along the line where it is desired 

 the stone shall break, and into each of these two thin half round i)ieces 

 of soft iron called " feathers " are placed, and a small steel wedge or 

 " l)lug" placed between. The quarryman then moves along this line 

 striking M'ith his hammer each wedge in its turn till the desired strain 

 is ])roduced and the stone falls apart. 



There is a chance for a greater disi)lay of skill in this work than may 

 at first appear. Nearly every stone, however conq)act, has a distinct 

 grain and rift, along which it can be relied on tos[)lit with comparative 

 ease and safety. To know the rift and be able to take ]noper advantage 



* F. W. Sperr. Report Tenth Ceusus, p. 37. 

 Wp. cit., p. 38. 



