316 REPORT ON NATIONAL MUSEUM, 1886. 



block is trimmed down to a line. Then the irregular surface is worked 

 down by the point, which is driven by the hand hammer. After point- 

 ing, are used the pean and the patent or bush hammers in turn, begin- 

 ning with the 4-cut and thence working down with the 6-cut, 8-cut, 10- 

 cut, and 12-cut, or until the desired surface is obtained. The condition 

 of the hammered surface at the completion of one of the hammerings 

 should be such that each cut in the hammer traces a line its full length 

 on the stone at each blow. 



The single cut or pean hammer should leave no uuevenness exceed- 

 ing one-eighth of an inch, and each finer cut reduces the unevenness 

 left by the preceding. 



The 12-cut should leave no irregularities upon the surface of the 

 stone other than the indentations made by the impinging of the plates 

 in the hammer. The lines of the cut are made so as to be vertical in 

 exposed vertical faces when the block is in position. On horizontal 

 and unexposed faces they are cut straight across in any convenient di- 

 rection. With sawn surfaces of course much of the preliminary work 

 is done away with, as the surface is already sufficiently smooth. It is 

 at present customary to saw only such stone as are designed for polish- 

 ing or some kind of smooth finish. 



In preparing a stone for polishing the surface is first made smooth as 

 possible by sawing or by the means above designated. It is then fur- 



which is of stone, was erected about 1730. Hence we must conclude that the art of 

 splitting stone in this manner was known to some at least as early as this date. 



It is stated (Grueber, Die Baumaterialieu-Lehre, pp. 60, 61) that in Finland, even at 

 the present day, granite is split from the quarry-bed through the expansive force of 

 ice. A scries of holes, from a foot to 15 inches apart and from 2 to 3 feet deep, accord- 

 ing to the size of the block to be loosened, is driven along the line of desired rift after 

 the usual custom. These holes are then rilled with water and tightly plugged. The 

 operation is put off until late in the season and until the approach of a frost. The water 

 in the holes then freezes, and by its expansion fractures the rock in the direction of 

 the line of holes. Blocks of 400 tons weight are stated to be broken out in this way. 

 A more ancient method consisted in simply plugging the holes with dry wooden 

 wedges and then thoroughly saturating them with water, the swelling wood acting 

 in the same way as the freezing water. Another ancient and well-known method con- 

 sisted in building a fire around the stone, and when it was thoroughly heated striking 

 it with heavy hammers or throwing cold water upon it. In splitting stone the ancient 

 Eomans are said to have sprinkled the hot stone with vinegar, though whether they 

 thereby accelerated the splitting or caused the stone to break along definite lines is 

 not known. Quartz rocks, it is stated, can be made to split in definite directions by 

 wetting them while hot, or laying a wet cord along the line it is desired they shall 

 cleave. The wet line gives rise to a small crack, and the operation is completed by 

 striking heavy blows with wooden mallets. According to M. Eaimondi, the ancient 

 Peruvians split up the stone in the quarry by first heating it with burning straw and 

 then throwing cold water upon it. To carve the stone and obtain a bas-relief, this 

 writer contends that the workmen covered with ashes the lines of the designs which 

 they intended to have in relief, and then heated the whole surface. The parts of the 

 stone which were submitted immediatel3 r to the action of fire became decomposed to 

 a greater or less depth, while the designs, protected by ashes, remained intact. To 

 complete the work the sculptor had but to carve out the decomposed rock with his 

 copper chisel. 



