BUILDING AND ORNAMENTAL STONES. 313 



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

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

 ence to Plate III. Iu 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, however, the stone must be evenly 

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

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

 *• Milestones " and Berea grits of Ohio. Iu the New York quarries the 

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

 the necessity of channeling.* 



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

 all those of granite rock for throwing off 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. 



(5) 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 purpose, 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 pieces 

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

 "plug" placed between. The quarry mau then moves along this line 

 striking with his hammer each wedge in its turn till the desired strain 

 is produced and the stone falls apart. 



There is a chance for a greater display of skill in this work than may 

 at first appear. Nearly every stone, however compact, has a distinct 

 grain and rift, along which it can be relied on to split with comparative 

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



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

 \Op. cit, p. 38. 



